Female Carriers Research Articles

Lower Endogenous Estrogens in APOE4‐Positive Postmenopausal Women Associated with Lower Regional Brain Volumes

AbstractBackgroundDuring the menopause transition, levels of estradiol (E2) ecline. Although these changes are likely key determinants of cognition and brain structure during the menopause transition, how they are related to brain volume in women at elevated risk of Alzheimer’s disease (AD) is not known. We predict associations of endogenous E1 and E2 levels to regional brain volumes will depend on APOE4 carrier status, such that the associations between lower levels of E1 and E2 and lower regional brain volumes will be more positive among APOE4 carriers.MethodsParticipants were enrolled in MsBrain, a cohort study of postmenopausal women (n = 191, mean age 59.4 +/‐ 3.4 years, 45 APOE4 carriers, 84.3% white). Serum E1 and E2 were assessed using liquid chromatography‐tandem mass spectrometry. Cortical volume was measured and segmented by FreeSurfer software using individual T1w MPRAGE images. Cross‐sectional associations of interest were analyzed with APOE4 genotype (carrier versus noncarrier; excluding APOE2)ormone levels, and their interaction, as predictors and regional brain volumes (33 regions per hemisphere) as outcome measures using lme4 Package in R. Models controlled for, years of education, and body mass index.ResultsNeither APOE4 carrier status nor hormone levels were associated with brain volumes . However, significant interactions were observed between APOE4 carrier status and E2 levels in relation to volume of the right (p<.05) and left isthmus cingulate (p<.01), right and left middle temporal lobe (p<.05), and the left posterior cingulate (p<.05), such that the positive association between E2 and regional brain volumes was more positive among APOE4 carriers (Figure 1). Further, there was a significant interaction between APOE4 carrier status and E1 levels in relation to volumes of the right and left inferior parietal lobe (p<.05), right (p<.05) and left isthmus cingulate (p<.05), left cuneus (p<.05), left precuneus (p<.05), and left lingual gyrus (p<.05)(Figure 2).ConclusionAlthough some of these findings would be expected by chance, results suggest that lower levels of endogenous estrogens may be a risk factor for regional brain volume loss in female APOE4 carriers compared to non‐carriers.Supported by NIH RF1AG053504 and R01AG053504 (Thurston & Maki)

Amyloid‐, tau‐, and FDG‐PET in amyloid‐negative patients clinically diagnosed with early‐onset Alzheimer’s disease in the LEADS study

AbstractBackgroundNegative AD biomarkers are commonly found in patients with a clinical diagnosis of late‐onset AD, but little is known about biomarker‐negative patients diagnosed with sporadic Early Onset AD (EOAD, <65yo). We explored data from the Longitudinal Early‐onset Alzheimer’s Disease Study (LEADS) to identify such participants and explored amyloid‐, tau‐, and FDG‐PET.MethodsWe identified 380 patients who i) met clinical criteria for MCI or dementia due to AD, and ii) completed baseline amyloid‐PET (Florbetaben) and tau‐PET (Flortaucipir). Of these patients, 93 (24.5%) were amyloid‐PET negative based on a combination of visual read and quantification (“EOnonAD”). A subset of EononAD participants completed FDG‐PET (n = 63), 5 had follow‐up amyloid‐PET and 2 had follow‐up tau‐PET. 63 age‐matched cognitively normal controls were also included. Image acquisition and processing followed ADNI protocols.ResultsCompared to amyloid‐positive patients (EOAD), EononAD patients were less frequently female or APOE4 carriers, and less severely impaired (Figure 1). EononAD patients had a mean Centiloid of 5.6 (Figure 2A). At the group level, temporal Flortaucipir‐SUVR was low (1.20.3, not significantly different from controls), although 3 cases had Flortaucipir‐SUVR>2 (Figure 2A). Visual inspection showed these cases had asymmetric AD‐like Flortaucipir‐PET patterns (Figure 2B). Within patients with EononAD, amyloid‐ and tau‐PET were correlated (Spearman’s ρ = 0.29, p = 0.005), even when excluding the 3 high Flortaucipir‐SUVR outliers (Figure‐2C). 5 patients had follow‐up amyloid‐PET: 2 showed major amyloid‐PET increase (+20 CL over 3 years), exceeding the 25 CL threshold at follow‐up, while the other 3 remained amyloid‐negative (Figure 2D). Two patients had follow‐up Flortaucipir‐PET: a low‐Flortaucipir case remained low, and one of the three high‐tau cases showed increased signal over time (Figure 2D). Group‐level FDG‐PET analysis showed frontal, temporal, and/or parietal hypometabolism in EOnonAD (Figure 3A). However, individual maps showed high heterogeneity: while ∼50% showing no clear hypometabolism (normal‐looking FDG), the remaining cases showed heterogeneous patterns suggestive of various underlying etiologies (e.g., FTLD‐like or AD‐like patterns, Figure 3B).ConclusionsAmyloid‐PET negative patients included in LEADS are heterogeneous. While a minority of cases might have underlying AD with subthreshold amyloid‐ and/or tau‐PET values, FDG‐PET showed heterogeneous patterns suggesting underlying etiologies include various degenerative and non‐degenerative causes.

Sex‐specific neuropsychiatric burden distinguished by APOE4 status and cortical thickness

AbstractBackgroundThe APOE ε4 (APOE4) allele is a genetic risk factor for Alzheimer’s disease (AD). Prior work by our group found a significant association between the APOE4 allele and presence of psychosis as well as overall increased neuropsychiatric symptom (NPS) burden in female APOE4 homozygote AD patients, with no effect present in males. In this study, we sought to examine the relationship between APOE4 carrier status and sex on NPS burden from a neuroimaging perspective, with the aim to determine what brain regions may be driving this effect.MethodA cohort of 752 AD patients were selected from the National Alzheimer’s Coordinating Center (NACC) database: 104 APOE4 homozygotes (40F|64M), 304 APOE4 heterozygotes (160F|144M) and 310 APOE4 non‐carriers (131F|179M). Presence of NPS was identified using the Neuropsychiatric Inventory (NPI). Structural T1‐weighted images were downloaded from the NACC imaging dataset and cortical thickness measures corresponding to frontal, cingulate, temporal and parietal regions were assessed. Statistical analysis included a Bayesian multilevel regression where cortical thickness was modeled as an outcome variable against an interaction between sex and APOE4 homozygote status (0|1), while controlling for heterozygote status, APOE4 non‐carrier status, age, sex and MMSE as predictor variables. Within‐ and between‐groups mean differences in thickness were measured as a probability density estimate (Highest Density interval), and partial correlation was used to examine NPI correlates to thickness.ResultFemale APOE4 homozygotes displayed a high probability (>90%HDI) of greater cortical thickness in the posterior cingulate and isthmus cingulate regions bilaterally and reduced cortical thickness in temporal regions (Figure 1). Cortical thickness in the fusiform cortex was positively correlated to greater NPI burden (p<0.05) among female homozygotes, and negatively correlated to NPI burden among female heterozygotes. Cortical thickness in males, regardless of carrier status, did not correlate to NPI burden in any region.ConclusionThis study highlights an important relationship between the fusiform cortex and NPI burden in female APOE4 carriers, marking a female‐specific effect. Future work should further disentangle sex differences in APOE4 status and psychosis with a focus on the fusiform cortex as a potential region of interest.

Amyloid‐, tau‐, and FDG‐PET in amyloid‐negative patients clinically diagnosed with early‐onset Alzheimer’s disease in the LEADS study

AbstractBackgroundNegative AD biomarkers are commonly found in patients with a clinical diagnosis of late‐onset AD, but little is known about biomarker‐negative patients diagnosed with sporadic Early Onset AD (EOAD, <65yo). We explored data from the Longitudinal Early‐onset Alzheimer’s Disease Study (LEADS) to identify such participants and explored amyloid‐, tau‐, and FDG‐PET.MethodWe identified 380 patients who i) met clinical criteria for MCI or dementia due to AD, and ii) completed baseline amyloid‐PET (Florbetaben) and tau‐PET (Flortaucipir). Of these patients, 93 (24.5%) were amyloid‐PET negative based on a combination of visual read and quantification (“EOnonAD”). A subset of EononAD participants completed FDG‐PET (n = 63), 5 had follow‐up amyloid‐PET and 2 had follow‐up tau‐PET. 63 age‐matched cognitively normal controls were also included. Image acquisition and processing followed ADNI protocols.ResultCompared to amyloid‐positive patients (EOAD), EononAD patients were less frequently female or APOE4 carriers, and less severely impaired (Figure 1). EononAD patients had a mean Centiloid of 5.6 (Figure 2A). At the group level, temporal Flortaucipir‐SUVR was low (1.20.3, not significantly different from controls), although 3 cases had Flortaucipir‐SUVR>2 (Figure 2A). Visual inspection showed these cases had asymmetric AD‐like Flortaucipir‐PET patterns (Figure 2B). Within patients with EononAD, amyloid‐ and tau‐PET were correlated (Spearman’s ρ = 0.29, p = 0.005), even when excluding the 3 high Flortaucipir‐SUVR outliers (Figure‐2C). 5 patients had follow‐up amyloid‐PET: 2 showed major amyloid‐PET increase (+20 CL over 3 years), exceeding the 25 CL threshold at follow‐up, while the other 3 remained amyloid‐negative (Figure 2D). Two patients had follow‐up Flortaucipir‐PET: a low‐Flortaucipir case remained low, and one of the three high‐tau cases showed increased signal over time (Figure 2D). Group‐level FDG‐PET analysis showed frontal, temporal, and/or parietal hypometabolism in EOnonAD (Figure 3A). However, individual maps showed high heterogeneity: while ∼50% showing no clear hypometabolism (normal‐looking FDG), the remaining cases showed heterogeneous patterns suggestive of various underlying etiologies (e.g., FTLD‐like or AD‐like patterns, Figure 3B).ConclusionAmyloid‐PET negative patients included in LEADS are heterogeneous. While a minority of cases might have underlying AD with subthreshold amyloid‐ and/or tau‐PET values, FDG‐PET showed heterogeneous patterns suggesting underlying etiologies include various degenerative and non‐degenerative causes. ”

Not all regions are created equal: identifying regions and cell types associated with cognitive resilience in the AD‐BXD model population

AbstractBackgroundThe relationship between regional cell composition, brain pathology, and memory impairment in Alzheimer’s disease (AD) remains incompletely understood. The specific brain regions and tracts (and their interactions) that explain the heterogeneity of cognitive decline with AD are not clear. By integrating brain‐wide immunohistochemistry and cognitive outcomes we can achieve unbiased detection of regions of interest (ROIs) and identify cellular correlates of cognitive resilience for causal testing.MethodImmunohistochemistry(IHC) was completed to evaluate neurodegeneration (NeuN), gliosis (Iba1&GFAP), amyloid beta(Aβ) pathology(AB1‐42), and cell bodies(Thionine) in adult (6 months(m)) and middle‐aged (14m) mice of the AD‐BXD genetic reference panel (n = 227). Using the QUINT workflow, hemibrain slices were systematically segmented and registered to the Allen Brain Atlas to gain a global perspective of percent cell and pathology coverage. IHC traits were correlated with contextual fear conditioning outcomes to identify regions whose stain composition is associated with memory performance.ResultsContrary to our prior work using ELISA‐based Aβ measurement, we find that Aβ quantified via IHC at the presymptomatic time point (6m) is strongly correlated with differences in short‐ and long‐term memory in 14m female 5XFAD carriers. Furthermore, the degree of astrogliosis at 6m in cortical, striatal, and thalamic regions acts as a predictor of cognitive outcomes at 14m. While age‐related decreases in NeuN load were not observed, wide variation in neurodegeneration levels could be attributed to strain differences and 14m NeuN load was positively correlated with 14m long‐term memory among this female 5XFAD population. Highlighting the importance of genetic background on AD progression, we were able to categorize strains as resilient or susceptible to pathological and cognitive decline and evaluate the overlap of these traits. Strains that exhibit the unique identity of being pathologically susceptible but cognitively resilient offer a novel opportunity to investigate the underlying mechanisms of protection from cognitive decline with AD.ConclusionIntegrating brain‐wide IHC and behavioral data, we were able to identify regional and cellular correlates that may predict downstream cognitive outcomes. Detection of these biomarkers may prove a valuable resource to disseminate the insidious prodromal stages of AD in which biochemical changes precede apparent clinical symptoms.

Clinical characteristics of carriers of pathogenic LDLR and АРОВ mutations

Aim. To analyze the clinical characteristics of carriers of pathogenic LDLR and АРОВ mutations, as well as the prognostic value of Dutch Lipid Clinic Network Score (DLCNS) as applied to carriage of АРОВ or LDLR.Material and methods. The study included 1233 outpatient lipid clinic patients. Biomaterial samples from 421 patients with the hereditary dyslipidemia were studied using Next Generation Sequencing (NGS) to identify carriage of familial hypercholesterolemia (FH)-associated genes (LDLR, АРОВ, PCSK9, LDLRAP1), as well as polymorphism of the APOE gene. Statistical processing was performed using descriptive statistics methods.Results. According to the data obtained, the most significant predictors of pathogenic LDLR mutations are the levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), family history of coronary artery disease (CAD), and previous coronary artery bypass grafting. The level of LDL-C, family history of cerebrovascular accident or CAD, and arcus senilis were more significant for verifying the carriage of pathogenic АРОВ mutations. Using screening potential carriers of FH using the DLCN or Simon-Broome diagnostic criteria, the probability of FH may be underestimated due to the discrepancy between the scale criteria and the prognostic contribution of clinical or anamnestic data. These scales do not take into account the estrogen status of potential female carriers of FH.Conclusion. Thus, diagnostic criteria for identifying potential FH vary among different patient groups. Their diagnostic significance depends on sex, and in women, on reproductive status. Only part of DLCN and Simon-Broome criteria can be applied to assess the FH likelihood, and to a greater extent for carriage of LDLR, but not АРОВ.

Delineation of an inverted tandem Xq23-26.3 duplication in a female featuring extremely short stature and mild mental deficiency

BackgroundPartial duplications involving the long arm of the X chromosome are associated with mental retardation, short stature, microcephaly, and a wide range of physical findings. Female carriers usually have no clinical phenotype. Occasionally, they may also have heterogeneous features due to non-random inactivation of the X chromosome.MethodsThe peripheral blood sample was collected from the patient and subjected to a few genetic testing, including chromosomal karyotyping, Chromosomal microarray analysis (CMA), Optical genome mapping, short tandem repeat (STR) analysis for Determination of parental origin, and X chromosome inactivation (XCI) analysis.ResultsWe have identified a de novo Xq23-Xq26.3 duplication in an adult female featuring extremely short stature and mild mental deficiency. Chromosome analysis detected a duplication on Xq23-q26.3 with a size of approximately 20 Mb. The duplication region has encompassed a number of genes, among which ARHGEF6, PHF6, HPRT1 and SLC9A6 are associated with X-linked mental retardation. Further analysis suggested that the duplication has derived from her father, was of the inversion duplication type and involved various degrees of skewed X chromosome inactivation.ConclusionCorrelation with her phenotypes might indicate new mechanisms by which the X chromosome may lead to short stature and mental retardation. Our findings thereby may shed more light on the phenotypic implication of functional disomy of X-chromosome genes.

Female Hemophilia in a Set of Triplets

Female Hemophilia In A Set Of Triplets Introduction: Hemophilia A (HA) and B (HB) are the most common inherited bleeding disorders. Gene sequencing identifies specific mutations and their associations with plasma factor levels and clinical phenotypes. Both HA and HB are X-linked recessive disorders, where the female carriers pass the gene onto their descendants. Males who inherit the mutated gene from their mothers develop the disease, whereas females are carriers due to having one normal gene, they typically do not display the characteristic features of hemophilia and have moderately low factor VIII levels of less than 40%. Female carriers may have bleeding symptoms, yet they do not experience as severe morbidities as the male hemophilia patients, due to having higher plasma factor VIII levels. Rarely female carriers can be severely affected and may have plasma factor VIII activities comparable to those with severe hemophilia. Here we are presenting a set of triplets, where the male infant and one of his sisters have severe hemophilia while the other sister is a hemophilia carrier. Methods: A set of triplets a male and two female neonates were born after 33 weeks of gestation to a healthy mother. Female neonates were dichorionic but shared the same placenta. The male infant had a circumcision at six weeks of age, which was complicated with prolonged bleeding. He was brought to the hospital and was diagnosed with severe HA. (Table.1). Infant #2 was admitted to the hospital for skin rash at age 8 weeks. She had staphylococcal scalded skin syndrome and was treated with vancomycin and cephalexin. She was noted to have prolonged bleeding from needle puncture sites. She was diagnosed with severe HA. The bleeding was controlled with tight packing. After a week of treatment her rash cleared, and she was discharged home. (Table 1). Infant #3 She was a healthy baby with no bleeding problems. (Table 1). Results and conclusions: We presented three infant-triplets-with factor VIII deficiency; infant #1 and infant #2 have severe HA. Infant #3 is an asymptomatic carrier. They all have the same mutation as their asymptomatic carrier mother. Infant #1 the male infant developed severe HA due to having the hemophilia allele on his “X” chromosome. Infant #3 a female infant is an asymptomatic carrier. She inherited the hemophilia allele on the X chromosome from her carrier mother and has an X chromosome bearing the normal allele, thus is able to produce factor VIII of 40%. Infant #2 the other female infant had severe HA, with a factor VIII activity of <0.3%. Female hemophilia is rare occurrence. Hemophilia treatment center (HTT) population profile (PP) reported that of the 1,676 females attending to HTC, 47.6% of them had less than 40% factor level, 0.48% of them had severe, 1.4% had moderate and 17.9% had mild hemophilia[Haemophilia. 2021:27(6):1037-1044. Doi:10.1111}. This can occur, in the setting of monosomy X (Turner syndrome-XO), due to having one X chromosome carrying the hemophilic gene or in the setting of compound heterozygosity: the female product of a father with hemophilia and the mother being a carrier. Similarly, hemizygosity of the hemophilic gene on both parents would result in hemophilia in their daughters. Another mechanism that plays a role in the pathogenesis of female hemophilia is the “X chromosome inactivation (XCI). This has been described as the most common cause of female hemophilia. One of the two X chromosomes in females is randomly and permanently inactivated in cells to ensure the balance with one X chromosome of males and limit the overproduction of potentially toxic gene proteins. The degree of inactivation determines the plasma levels of the gene products, in hemophilia the factor levels. The chromosome analysis of infant #2 revealed normal 46XX. Structural chromosomal abnormality is ruled out as she did not have Turner syndrome “XO”, or “45XY” with androgen insensitivity syndrome, nor did she have compound heterozygosity or hemizygosity of the X chromosome. The father had normal coagulation studies and factor VIII activity. Therefore, we believe infant #2 had extremely skewed XCI and the inactivation is skewed in favor of hemophilic X chromosome. This mechanism resulted in severe HA in this infant. The infants are now seven months old and have no bleeding problems, as infant #1 and #2 are on prophylaxis with emicizumab (Hemlibra), they both have 1% factor activity by chromogenic assay and do not have inhibitors. (Table 1)

Comparison of Projected Hemophilia a Populations Residing in Hospital Referral Regions with and without Hemophilia Treatment Centers in the US

Introduction: Among the approximately 53,000 people with hemophilia A (PwHA) in the US, a majority receive care at federally supported hemophilia treatment centers (HTCs). PwHA treated at HTCs have more favorable outcomes and are more likely to receive advanced therapies than PwHA receiving care external to the HTC network. Identifying geographic, socioeconomic and racial disparities among populations residing in hospital referral regions (HRRs) with and without HTCs will support efforts to improve care access and advance health equity. The objective of this study was to evaluate geographic, socioeconomic and racial differences in modeled US populations of PwHA who reside within HRRs with and without HTCs. Methods: Characteristics of HRRs with and without HTCs were compared using the Centers for Disease Control and Prevention (CDC) HTC listings. The study cohorts included individuals who resided in HRRs with and without an HTC based on modeled US populations of projected PwHA (pPwHA). The number of males with hemophilia A in each HRR was calculated at a rate of 12 cases per 100,000 males in the region of interest based on CDC estimates, and the number of females who were carriers of hemophilia A was calculated at a rate of 0.6 female carriers per male case as defined by the International Society of Thrombosis and Haemostasis Scientific and Standardization Committee. Demographic characteristics for each HRR were derived from the 2020 5-year American Community Survey; zip code tabulation areas were crosswalked to 5-digit zip codes and aggregated to HRRs.Differences in population characteristics in HRRs with and without HTCs were evaluated for statistical significance using the Wilcoxon rank sum test. Results: In 307 HRRs in the US, 109 had an associated HTC, while 198 did not (Figure). However, larger mean (SD) populations comprised HRRs with HTCs than those without (3,183,191 [2,752,401] vs 906,047 [814,847]; P<0.001; Table). Findings from this modeling work indicate that 78% of pPwHA reside in HRRs with an HTC. HRRs with HTCs served populations with greater proportions of Asian (5.3% vs 3.0%) and Black (14% vs 11%) individuals than those without HTCs ( P<0.001 for both). Compared with those in HRRs without HTCs, individuals residing in HRRs with HTCs had a wider range of median incomes ($27,978-$184,456 vs $35,087-$138,168; P<0.001) and a greater likelihood of falling above the 150% federal poverty line (77.9% vs 76.3%; P=0.014). Additionally, those residing in HRRs with HTCs were less likely to drive to work (75.0% vs 79.0%) and more likely to take public transit (4.4% vs 1.7%) or walk (3.0% vs 2.1%) than people in HRRs without HTCs ( P<0.001 for all). Conclusions: This analysis estimated that in the US, 4 of 5 pPwHA reside in an HRR with HTC access. HRRs with HTCs served larger populations with greater racial and socioeconomic diversity than HRRs without HTCs. While it is possible that PwHA who reside in HRRs without HTCs can still receive adequate care via outreach clinics, mobile units or virtual appointments, this work highlights that geographic barriers to HTC access remain incompletely addressed. Future efforts should focus on accurately identifying US hemophilia A populations and their locations relative to HTCs and comparing the impact on care and outcomes in those who rely on outreach efforts or mobile programs.

Stratification of the risk of ovarian dysfunction by studying the complexity of intermediate and premutation alleles of the FMR1 gene.

FMR1 premutation female carriers are at risk of developing premature/primary ovarian insufficiency (POI) with an incomplete penetrance. In this study, we determined the CGG repeat size among 1095 women with diminished ovarian reserve (DOR) / POI and characterized the CGG/AGG substructure in 44 women carrying an abnormal FMR1 repeat expansion number, compared to a group of 25 pregnant women carrying an abnormal FMR1 CGG repeat size. Allelic complexity scores of the FMR1 gene were calculated and compared between the two groups. In the DOR/POI cohort, 2.1% of women presented with an intermediate repeat size and 1.9% with a premutation. Our results suggest that the risk of POI is highest in the mid-range of CGG repeats. We observed that the allelic score is significantly higher in POI women compared to the pregnant women group (p-value = 0.02). We suggest that a high allelic score due to more than 2 AGG interspersions in the context of an intermediate number of repetitions could favor POI. Larger studies are still needed to evaluate the relevance of this new tool for the determination of the individual risk of developing POI in women with abnormal number of CGG repeats.

The effect of genetic defects on pregnancy loss in Swedish dairy cattle

The effect of carrier status of 10 lethal recessive genetic defects on pregnancy maintenance in Swedish dairy cattle was examined. The genetic defects were Ayrshire Haplotype 1, Ayrshire Haplotype 2, BTA12, BTA23, and Brown Swiss Haplotype 2 in Red Dairy Cattle (RDC), and Holstein Haplotype 1, 3, 4, 6, and 7 (HH1-HH7) in Holstein. Effects of carrier status of BTA12 and HH3 on conception rate (CR), interval from first to last service (FLS), and milk production were also examined. Data were obtained for 1,429 herds in the Swedish milk recording system, while information on carrier status of genetic defects was obtained from the Nordic Cattle Genetic Evaluation. In total, data on 158,795 inseminations in 28,432 RDC and 22,018 Holstein females were available. Data permitted separate analyses of BTA12 and HH3, but carrier frequencies of other defects were too low to enable further analysis. Pregnancy loss was defined as failure to maintain pregnancy, where pregnancy status was confirmed with manual and chemical pregnancy diagnosis, insemination, calving, sales and culling data. Odds ratios (OR) and probabilities of pregnancy loss and CR were estimated using generalized linear mixed models, while pregnancy loss, CR, FLS, milk, protein, and fat yields were analyzed using linear mixed models. Pregnancy losses were reported on average within the first month post-AI. At-risk matings were more prone to suffer pregnancy loss in BTA12 (OR = 1.79) and HH3 carriers (OR = 1.77) than not-at-risk matings. At-risk matings also had lower CR (OR = 0.62 and 0.63 for BTA12 and HH3, respectively) than not-at-risk matings. Carrier females of BTA12 had longer FLS and higher milk production than noncarriers. Conception rate and pregnancy maintenance could be improved by avoiding at-risk matings. This finding could help reduce pregnancy loss due to genetic defects in the breeding program for improved fertility.

RP2-Associated X-linked Retinopathy: Clinical Findings, Molecular Genetics, and Natural History in a Large Cohort of Female Carriers

RP2-associated retinopathy typically causes severe early onset retinitis pigmentosa (RP) in affected males. However, there is a scarcity of reports describing the clinical phenotype of female carriers. We tested the hypothesis that RP2 variants manifest in female carriers with a range of functional and anatomic characteristics. Retrospective case series. Females with disease-causing variants in RP2 were identified from investigation of pedigrees affected by RP2 retinopathy. All case notes and results of molecular genetic testing, retinal imaging (fundus autofluorescence imaging, optical coherence tomography (OCT)), and electrophysiology were reviewed. Forty pedigrees were investigated. Twenty-nine pedigrees had obligate carriers or molecularly confirmed female members with recorded relevant history and/or examination. For 8 pedigrees, data were available only from history, with patients reporting affected female relatives with RP in 4 cases and unaffected female relatives in the other 4 cases. Twenty-seven females from 21 pedigrees were examined by a retinal genetics specialist. Twenty-three patients (85%) reported no complaints and had normal vision and 4 patients had RP-associated complaints (15%). Eight patients had normal fundus examination (30%), 10 had a tapetal-like reflex (TLR; 37%), 5 had scattered peripheral pigmentation (19%), and the 4 symptomatic patients had fundus findings compatible with RP (15%). All asymptomatic patients with normal fundus, TLR, or asymptomatic pigmentary changes had a continuous ellipsoid zone on OCT when available. The electroretinograms revealed mild to severe photoreceptor dysfunction in 9 of 11 subjects, often asymmetrical, including 5 with pattern electroretinogram evidence of symmetrical (n = 4) or unilateral (n = 1 subject) macular dysfunction. Most carriers were asymptomatic, exhibiting subclinical characteristics such as TLR and pigmentary changes. However, female carriers of RP2 variants can manifest RP. Family history of affected females with RP does not exclude X-linked disease. The phenotypic spectrum as described herein has prognostic and counselling implications for RP2 carriers and patients.

Sensorimotor and inhibitory control in aging FMR1 premutation carriers.

Aging FMR1 premutation carriers are at risk of developing neurodegenerative disorders, including fragile X-associated tremor/ataxia syndrome (FXTAS), and there is a need to identify biomarkers that can aid in identification and treatment of these disorders. While FXTAS is more common in males than females, females can develop the disease, and some evidence suggests that patterns of impairment may differ across sexes. Few studies include females with symptoms of FXTAS, and as a result, little information is available on key phenotypes for tracking disease risk and progression in female premutation carriers. Our aim was to examine quantitative motor and cognitive traits in aging premutation carriers. We administered oculomotor tests of visually guided/reactive saccades (motor) and antisaccades (cognitive control) in 22 premutation carriers (73% female) and 32 age- and sex-matched healthy controls. Neither reactive saccade latency nor accuracy differed between groups. FMR1 premutation carriers showed increased antisaccade latencies relative to controls, both when considering males and females together and when analyzing females separately. Reduced saccade accuracy and increased antisaccade latency each were associated with more severe clinically rated neuromotor impairments. Findings indicate that together male and female premutation carriers show a reduced ability to rapidly exert volitional control over prepotent responses and that quantitative differences in oculomotor behavior, including control of visually guided and antisaccades, may track with FXTAS - related degeneration in male and female premutation carriers.

X-linked adrenoleukodystrophy and primary adrenal insufficiency.

X-linked adrenoleukodystrophy (X-ALD; OMIM:300100) is a progressive neurodegenerative disorder caused by a congenital defect in the ATP-binding cassette transporters sub-family D member 1 gene (ABCD1) producing adrenoleukodystrophy protein (ALDP). According to population studies, X-ALD has an estimated birth prevalence of 1 in 17.000 subjects (considering both hemizygous males and heterozygous females), and there is no evidence that this prevalence varies among regions or ethnic groups. ALDP deficiency results in a defective peroxisomal β-oxidation of very long chain fatty acids (VLCFA). As a consequence of this metabolic abnormality, VLCFAs accumulate in nervous system (brain white matter and spinal cord), testis and adrenal cortex. All X-ALD affected patients carry a mutation on the ABCD1 gene. Nevertheless, patients with a defect on the ABCD1 gene can have a dramatic difference in the clinical presentation of the disease. In fact, X-ALD can vary from the most severe cerebral paediatric form (CerALD), to adult adrenomyeloneuropathy (AMN), Addison-only and asymptomatic forms. Primary adrenal insufficiency (PAI) is one of the main features of X-ALD, with a prevalence of 70% in ALD/AMN patients and 5% in female carriers. The pathogenesis of X-ALD related PAI is still unclear, even if a few published data suggests a defective adrenal response to ACTH, related to VLCFA accumulation with progressive disruption of adrenal cell membrane function and ACTH receptor activity. The reason why PAI develops only in a proportion of ALD/AMN patients remains incompletely understood. A growing consensus supports VLCFA assessment in all male children presenting with PAI, as early diagnosis and start of therapy may be essential for X-ALD patients. Children and adults with PAI require individualized glucocorticoid replacement therapy, while mineralocorticoid therapy is needed only in a few cases after consideration of hormonal and electrolytes status. Novel approaches, such as prolonged release glucocorticoids, offer potential benefit in optimizing hormonal replacement for X-ALD-related PAI. Although the association between PAI and X-ALD has been observed in clinical practice, the underlying mechanisms remain poorly understood. This paper aims to explore the multifaceted relationship between PAI and X-ALD, shedding light on shared pathophysiology, clinical manifestations, and potential therapeutic interventions.

A pilot study of newborn screening for X-linked adrenoleukodystrophy based on liquid chromatography-tandem mass spectrometry method for detection of C26:0- lysophosphatidylcholine in dried blood spots: results from 43,653 newborns in a southern Chinese population

BackgroundX-linked adrenoleukodystrophy (X-ALD) is a rare X-linked disease caused by mutations of the ABCD1 gene. C26:0-lysophosphatidylcholine (C26:0-LPC) has been proved to be an accurate biomarker for X-ALD. This study aims to propose an effective method for screening of X-ALD and to evaluate the performance of the newborn screening (NBS) assay for X-ALD in Guangzhou. MethodsC26:0-LPC in dried blood spots (DBS) was extracted by methanol solution containing isotope-labelled internal standard (C26:0-d4-LPC) and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The sensitivity of the method was assessed in eight male X-ALD patients, two female carriers and 583 healthy controls. The method was conducted on 43,653 newborns. Next generation sequencing was performed on screen-positive samples. Plasma analysis of very long-chain fatty acids and genetic counselling were performed by way of follow-up. ResultsElevated C26:0-LPC were 100% sensitive for screening of X-ALD. Of 43,653 newborns, 32 (18 males, 14 females) screened positive. Of these, 14 (43.7%) were identified ABCD1 variants, including seven hemizygous males and seven heterozygous females, and two (6.3%) were diagnosed with other peroxisomal disorders. ConclusionThe LC-MS/MS method for screening of X-ALD can identify males, heterozygous females and other peroxisomal disorders. The incidence of X-ALD in Guangzhou is not low.

Cardiovascular phenotype of the duchenne muscular dystrophy carrier female rat

Abstract Background Duchenne muscular dystrophy (DMD) is a lethal, severely progressive muscle-wasting disease. It is an X-linked recessive disease caused by mutations in the DMD gene encoding dystrophin protein and consequently the absence of dystrophin protein synthesis. Besides the skeletal muscle abnormalities, DMD patients are often suffering cardiovascular symptoms include cardiac fibrosis, dilated cardiomyopathy, arrhythmia, and congestive heart failure. Heterozygous female DMD carriers rarely acquire skeletal muscle symptoms, however the cardiac abnormalities are often underrepresented. There are few studies to date characterizing cardiovascular abnormalities in female DMD carriers and the mechanisms underlying the cardiac manifestations are still not fully known. Aims and Methods: Therefore, the aim of this study was to investigate the cardiovascular phenotype of 9 months old female DMD carrier rats and compare with age-matched wildtype rats. Objectives included assessment of cardiac function via transthoracic echocardiography, vascular function using wire myography, cardiac fibrosis and dystrophin via histology, mRNA expression of inflammatory markers via RT-qPCR, measurements of ACE1 and ACE2 activity, as well as expression of dystrophin, SERCA, sarcolipin, BAG3, and Connexin43 (Cx43) using western blotting. The cardiac function, vascular endothelial function, ACE1 and ACE2 activity, and collagen deposition in cardiac tissue were similar between the female DMD carrier and wildtype rats. The echocardiography data revealed thinning of the left-ventricular posterior wall indicating trend towards cardiac atrophy and dysfunction (p<0.05). Wire myography data showed trends of impaired endothelium-independent relaxation and hypercontractility, suggesting the potential vascular abnormalities. Histological analysis showed thickening of intima-media layer in coronary arteries, addition to reduced dystrophin staining, further affirming dystrophin loss impairs smooth muscle cell function (p<0.05, respectively). Protein expression of dystrophin, SERCA2, and BAG3 was decreased in female DMD carrier rats in the myocardium. We also found decreased levels of Cx43 at the intercalated discs, with a concomitant increase in the phosphorylation of Serine368 on Cx43 that very often precedes ubiquitination and degradation of Cx43 channels. In agreement, higher levels of the ubiquitin ligase Nedd4 were observed in hearts of female DMD carrier rats, implicating Cx43 degradation in cardiac dysfunction observed in these animals. Conclusions These findings indicate that female DMD carrier rats do not develop severe cardiac systolic dysfunction nor dilated cardiomyopathy at the age of 9 months unlike male DMD rats as previously described(1). However, the female DMD carrier rats begin to manifest tendencies towards cardiac and vascular dysfunction in association with a changes of calcium handling protein and Cx 43 expression in the heart.

Influence of left ventricular ejection fraction, type of mutation and sex on malignant ventricular arrhythmias in dsp and flnc mutations

Abstract Introduction Pathogenic mutations in FLNC and DSP are a common cause of arrhythmogenic left ventricular cardiomyopathy and "arrhythmic dilated cardiomyopathy". We aimed to study demographic and clinical differences amongst these carriers. Purpose 1. To study the prevalence of malignant ventricular arrhythmias in DSP and FLNC mutation carriers in the studies and reports published in the literature. 2. To analyse the effect of age, left ventricular ejection fraction (LVEF), and sex on ventricular arrhythmias in both groups. Methods A systematic review of the human studies published in Medline and EMBASE until September 2022 was carried out. "Desmoplakin Mutations", "Filamin Mutations", "Arrhythmogenic Cardiomyopathy" and "Dilated Cardiomyopathy" were the keywords included in the search queries. Studies, family reports, and registries reporting on individual data of pathogenic or likely pathogenic mutation carriers were selected for analysis. Results Twenty-four articles published between 2002 and 2020 were selected from a total of 430 entries. 171 DSP carriers (from 16 studies) and 169 FLNC carriers (from 7 studies) were included in the analysis. Mean age was similar in both groups: 39.45±19.23 years in DSP vs 42.02±16.27 in the FLNC group (p:0.201). The proportion of females was higher among DSP carriers than that found among FLNC carriers: 101 (59%) vs 76 (45%), p: 0.012. Non-missense mutations were more frequent in both groups: 98 DSP carriers (57%) and 157 FLNC carriers (97%). LVEF was slightly more depressed amongst FLNC carriers: 47.75±14.94% vs 52.37±14.64%, p:0.014. A total of 81 major arrhythmic events (sudden death, ventricular fibrillation, sustained ventricular tachycardia were reported. The LVEF of the male patients that had suffered a major event was similar in both groups (39.13±18.20% in DSP vs 39.03±12.24% in FLNC, p:0.987). On the contrary, LVEF was significantly lower in female carriers of DSP mutations (32.33±15.65% in DSP vs 47.60±15.88% in FLNC, p:0.050). Male carriers show a worse prognosis than their female counterparts (log-rank 0.005) (Figure). The difference was not significant after adjusting for LVEF and type of mutation (missense vs non-missense). LVEF (HR 0.94 per percentage unit (0.91-0.96), p <0.001) and non-missense mutations (HR 0.21 (0.07-0.66), p:0.008) were inversely associated with adverse outcomes in DSP carriers in a multivariate analysis. LVEF was also associated with a better outcome in FLNC carriers (HR 0.97 (0.95-0.99), p: 0.019. Conclusion Moderate systolic dysfunction is a risk factor for malignant arrhythmias amongst DSP and FLNC mutation carriers. Female FLNC carriers with mild systolic dysfunction are at risk for sustained ventricular arrhythmias. Missense DSP mutations are associated with poor arrhythmic prognosis.Sex differences in survival

Random X-Chromosome Inactivation in Adult Hemophilia B Carriers Does Not Attenuate Bleeding Risk

Introduction: The X-linked bleeding disorder Hemophilia B (HB) results from deficiency in coagulation Factor IX (FIX). In contrast to Hemophilia A, genotype-phenotype correlations in HB males are complex, as some F9 variants in males are associated with low plasma FIX activity (FIX:C) but milder than expected bleeding phenotypes. At least 75% of FIX is extravascular and not adequately measured from plasma. Hemostasis is likely influenced by this extravascular FIX which is bound reversibly to type IV collagen in the subendothelial basement membrane. We predict that genotype-phenotype correlations in female carriers of F9 mutations may have additional complexity as the mutant FIX can competitively interfere with wild type (WT) FIX for extravascular binding sites. F9 expression in female HB carriers is influenced by X-chromosome inactivation (XCI), a process that silences one X in XX females. XCI results in cells that randomly inactivate either the X carrying the mutant or wild type F9, although skewed XCI (>80:20) is found in ~25% of the general population. XCI skewing in HB carriers can lead to preferential expression of the X carrying the F9 mutation, which in turn influences plasma and extravascular levels of FIX and bleeding tendency. How frequently XCI is skewed in HB carriers, and the role of XCI in modulating FIX levels and bleeding phenotypes, remains poorly understood. We sought to determine whether XCI skewing may further differentiate bleeding risk in HB carriers. Methods: Subjects were enrolled in a prospective, observational cross-sectional study with informed consent. Both the Condensed MCMDM-1 bleeding assessment tool (BAT) and Pictorial Blood-loss Assessment Chart (PBAC) were completed at the time of the visit. F9 mutation analysis confirmed carrier status. FIX:C and FIX antigen ELISA assays were performed on all subjects. XCI skewing was assessed using established assays at the Androgen Receptor (AR) and Fragile X Mental Retardation (FMR1) loci. Results: A total of 15 subjects (11 adults) were confirmed F9 mutation carriers; six missense mutations and one frameshift mutation were identified. Abnormal bleeding is frequent in adult HB carriers, with 5/11 (45%) having BAT scores >4. Heavy menstrual bleeding (HMB) is particularly frequent, with all adult HB carriers reporting PBAC > 100, and 8/11 with BAT HMB subcategory score >1. FIX assessment by activity (mean 56% ± 28) and antigen (mean 0.55 IU/mL ± 0.2) assays are highly correlated (r 2= 0.83, p < 0.0001). Notably, only two adult HB carriers with significant bleeding have FIX levels < 50%, while two HB carriers with FIX levels < 50% have BAT scores < 4, indicating that neither FIX:C nor FIX antigen levels adequately predict bleeding risk in all HB carriers. Indeed, for all 11 adult HB carriers, no significant differences in either FIX:C or FIX antigen were observed between those with BAT scores ≥ 4 and < 4. We asked if XCI explained FIX levels or bleeding phenotypes. Nearly half (5/11) of the adult carriers have moderately skewed XCI (> 70:30); only one is extremely XCI skewed (> 80:20), and of the individuals with skewed XCI, 3/5 have BAT scores ≥ 4. Although random XCI is proposed to attenuate HB carrier bleeding phenotype, 2/6 HB carriers with random XCI also have BAT scores ≥ 4. XCI weakly correlated with FIX antigen (n = 15; r 2= 0.27, p < 0.05) but not FIX:C. When assessing this relationship for only the individuals with F9 c.1025C>T (n = 6), there was significant correlation with FIX:C (R 2= 0.73, p < 0.05) but not with FIX antigen or bleeding phenotype. The lack of correlation between XCI and FIX antigen in individuals with an identical F9 mutation argues for additional influences on intravascular, and likely extravascular, FIX levels and will require further investigation. Conclusions: Bleeding tendency in HB carriers is not rare and does not correlate with plasma FIX:C or FIX antigen. Random XCI is not fully protective against abnormal bleeding. Future studies are needed to better understand bleeding phenotypes in HB carriers that consider XCI, F9 mutation type and influences on circulating levels of WT and mutant FIX.

Combined Bilateral Salpingo-oophorectomy and Cesarean Delivery in BRCA1/2 Alteration Carriers : A Case Series.

The cumulative lifetime risk of ovarian cancer is 16-68% and 11-30% in female BRCA1 and BRCA2 gene alteration carriers, respectively. Risk-reducing bilateral salpingo-oophorectomy (RRSO) is the only proven way to reduce ovarian cancer mortality. We report a series of patients who underwent risk-reducing surgery at the time of planned obstetric-indicated cesarean delivery. This is a case series of four women carrying a pathogenic germline BRCA1 or BRCA2 gene alteration who underwent RRSO at the time of cesarean delivery between March 1, 2018, and March 31, 2022. All women were referred during pregnancy to the University College London Hospitals Familial Cancer Clinic for consideration of RRSO at the time of obstetric-indicated cesarean delivery. Women were considered eligible for RRSO if they had a proven pathogenic germline alteration, would have completed childbearing after the cesarean delivery, and were older than age 35 or 40 years with BRCA1 or BRCA2 alterations, respectively. Operating time, blood loss, transfusion requirements, length of hospital stay, complications, and ability to breastfeed were assessed and, where possible, compared with the institutional means for similar patients who underwent cesarean delivery only, to determine whether RRSO was associated with increased morbidity. Women were contacted 11-59 months postprocedure to assess satisfaction. The mean blood loss was 687 mL (range 400-1,000 mL), mean operating time was 68 minutes, mean length of hospital stay was 3 days, and mean change in hemoglobin was -1 g/dL. No patient required a transfusion, had internal organ damage, returned to the operating room, or was readmitted. One of two women with intact breast tissue successfully breastfed, and the other chose to bottle feed. The mean contemporaneous institutional blood loss for cesarean delivery was not significantly different at 681 mL for singleton pregnancies and 872 mL for twin pregnancies. All four women reported a high level of satisfaction with the combined procedure. Our results show that RRSO can be performed at the time of cesarean delivery with high patient satisfaction. This approach can be offered to appropriately counseled individuals, with the benefit of avoiding the need for two separate procedures, with potentially reduced patient morbidity and health care costs.

10 Female APOE ε4 Carriers with Slow Rates of Biological Aging Have Better Verbal Memory Performance Compared to Female Carriers with Faster Rates of Aging, Independent of Chronological Age, Education, and Depressive Symptoms.

Objective:The presence of an e4 allele of the apolipoprotein E gene (APOE ε4) is considered the strongest genetic risk factor for Alzheimer’s disease (AD) in the US. Evidence suggests that APOE ε4 carriers have worse memory performances compared to APOE ε4 non-carriers in cognitively normal older adults and that female APOE ε4 carriers are at greater risk of AD compared to male carriers. Recent advancements in estimating biological age using DNA methylation markers may enhance understanding of the associations between sex and APOE ε4 on cognitive aging. Thus, the current study aimed to investigate whether associations between APOE ε4 status and memory vary according to rates of biological aging, using a DNA methylation age biomarker, in older men and women without dementia.Participants and Methods:Cross-sectional data were obtained from 1771 older adults enrolled in the 2016 wave of the Health and Retirement Study (Mean age = 75, SD = 7; 57% female; 76% non-Hispanic white). The standardized residual from regressing chronological age on the epigenetic clock “DNAGrimAge” was used as a measure of the aging rate. A series of ANCOVAs with Bonferroni corrected post hoc pairwise tests, adjusting for education, white blood cell count, chronological age, and depressive symptoms were used to test the main and interaction effects of APOE ε4 status (non-carriers = 0; carriers = 1) and aging rates, defined as 1 standard deviation below (i.e., slow rate), or above (i.e., fast rate) sex-specific mean rate (i.e., average) of aging, on a standardized composite measure of verbal memory. Alpha was set at .05 and all raw scores were converted to z-score metric prior to analyses.Results:APOE ε4 female carriers with slow rates of aging (n = 34) had significantly better memory performances compared to APOE ε4 female carriers with fast rates of aging (n = 41), mean difference = .61, p = .006, and average rates of aging (n = 170), mean difference = .44, p = .017. There was no effect of aging rate on memory in the female non-carriers and there were no significant differences in memory performances based on rates of aging in either male APOE ε4 carriers or non-carriers.Conclusions:Although the presence of the APOE ε4 has previously been shown to represent a stronger risk of AD for women compared to men, results from the current study suggest that slower rates of aging in this high-risk group may confer protection against clinical symptoms (i.e., memory impairment). Conversely, faster than average aging in female APOE ε4 carriers may represent a group at greater risk of memory impairment due to AD. However, longitudinal studies with larger sample sizes are needed to evaluate the risk of dementia/memory impairment based on rates of aging in female APOE ε4 carriers.