Female Probands Research Articles

Genome-wide study of gene-by-sex interactions identifies risks for cleft palate.

Structural birth defects affect 3-4% of all live births and, depending on the type, tend to manifest in a sex-biased manner. Orofacial clefts (OFCs) are the most common craniofacial structural birth defects and are often divided into cleft lip with or without cleft palate (CL/P) and cleft palate only (CP). Previous studies have found sex-specific risks for CL/P, but these risks have yet to be evaluated in CP. CL/P is more common in males and CP is more frequently observed in females, so we hypothesized there would also be sex-specific differences for CP. Using a trio-based cohort, we performed sex-stratified genome-wide association studies (GWAS) based on proband sex followed by a genome-wide gene-by-sex (G × S) interaction testing. There were 13 loci significant for G × S interactions, with the top finding in LTBP1 (RR = 3.37 [2.04-5.56], p = 1.93 × 10-6). LTBP1 plays a role in regulating TGF-β bioavailability, and knockdown in both mice and zebrafish lead to craniofacial anomalies. Further, there is evidence for differential expression of LTBP1 between males and females in both mice and humans. Therefore, we tested the association between the imputed genetically regulated gene expression of genes with significant G × S interactions and the CP phenotype. We found significant association for LTBP1 in cell cultured fibroblasts in female probands (p = 0.0013) but not in males. Taken altogether, we show there are sex-specific risks for CP that are otherwise undetectable in a combined sex cohort, and LTBP1 is a candidate risk gene, particularly in females.

Inherited PURA Pathogenic Variant Associated With a Mild Neurodevelopmental Disorder.

Purine-rich element-binding protein alpha (PURA) regulates gene expression and is ubiquitously expressed with an enrichment in neural tissues. Pathogenic variants in PURA cause the neurodevelopmental disorder PURA syndrome that has a variable phenotype but typically comprises moderate-to-severe global developmental delay, intellectual disability, early-onset hypotonia and hypothermia, epilepsy, feeding difficulties, movement disorders, and subtle facial dysmorphism. Speech is reportedly absent in most, but the specific linguistic phenotype is not well described. We used genome sequencing to identify a pathogenic gene variant as part of a study of children ascertained for severe primary speech disorder in the absence of moderate or severe ID. The novel PURA c.296G>T (p.Arg99Leu) pathogenic missense variant segregated in the female proband and her affected mother. The proband had dysarthria; phonological disorder; and severe receptive and expressive language impairment, borderline intellect, attention difficulties, oropharyngeal dysmotility, and dysmorphic facial features. Her mother had dysarthria, moderate receptive language impairment, and borderline intellect. Both the proband and her mother completed mainstream schooling with classroom support. This is the first inherited PURA pathogenic germline variant in over 600 unrelated families documented on ClinVar or reported in the literature. PURA testing should be considered in families with primary speech disorder and borderline intellectual disability, given the specific genetic counseling implications.

Genomic Balancing Act: deciphering DNA rearrangements in the complex chromosomal aberration involving 5p15.2, 2q31.1, and 18q21.32.

Despite extensive research into the genetic underpinnings of neurodevelopmental disorders (NDD), many clinical cases remain unresolved. We studied a female proband with a NDD, mildly dysmorphic facial features, and brain stem hypoplasia on neuroimaging. Comprehensive genomic analyses revealed a terminal 5p loss and aterminal 18q gain in the proband while a diploid copy number for chromosomes 5 and 18 in both parents. Genomic investigations in the proband identified an unbalanced translocation t(5;18) with additional genetic material from chromosome 2 (2q31.3) inserted at the breakpoint, pointing to a complex chromosomal rearrangement (CCR) involving 5p15.2, 2q31.3, and 18q21.32. Breakpoint junction analyses enabled by long-read genome sequencing unveiled the presence of four distinct junctions in the father, who is acarrier of a balanced CCR. The proband inherited from the father both the abnormal chromosome 5 resulting in segmental aneusomies of chr5 (loss) and chr18 (gain) and a der(2) homologue. Evidences suggest a chromoplexy mechanism for this CCR derivation, involving double-strand breaks (DSBs) repaired by non-homologous end joining (NHEJ) or alternative end joining (alt-EJ). The complexity of the CCR and the segregation of homologues elucidate the genetic model for this family. This study demonstrates the importance of combining multiple genomic technologies to uncover genetic causes of complex neurodevelopmental syndromes and to better understand genetic disease mechanisms.

Pseudodominant inheritance of retinitis pigmentosa in a family with mutations in the Eyes Shut Homolog (EYS) gene

Sequence variants in Eyes Shut Homolog (EYS) gene are one of the most frequent causes of autosomal recessive retinitis pigmentosa (RP). Herein, we describe an Italian RP family characterized by EYS-related pseudodominant inheritance. The female proband, her brother, and both her sons showed typical RP, with diminished or non-recordable full-field electroretinogram, narrowing of visual field, and variable losses of central vision. To investigate this apparently autosomal dominant pedigree, next generation sequencing (NGS) of a custom panel of RP-related genes was performed, further enhanced by bioinformatic detection of copy-number variations (CNVs). Unexpectedly, all patients had a compound heterozygosity involving two known pathogenic EYS variants i.e., the exon 33 frameshift mutation c.6714delT and the exon 29 deletion c.(5927þ1_5928-1)_(6078þ1_6079-1)del, with the exception of the youngest son who was homozygous for the above-detailed frameshift mutation. No pathologic eye conditions were instead observed in the proband’s husband, who was a heterozygous healthy carrier of the same c.6714delT variant in exon 33 of EYS gene. These findings provide evidence that pseudodominant pattern of inheritance can hide an autosomal recessive RP partially or totally due to CNVs, recommending CNVs study in those pedigrees which remain genetically unsolved after the completion of NGS or whole exome sequencing analysis.

Familial Recurrence of Autism: Updates From the Baby Siblings Research Consortium.

Autism spectrum disorder (ASD) is estimated to be ∼10 times higher in children with versus without an autistic sibling in population-based studies. Prospective studies of infant siblings have revealed even higher familial recurrence rates. In the current prospective longitudinal study, we provide updated estimates of familial ASD recurrence using a multinational database of infants with older autistic siblings. Data were collated across 18 sites of the Baby Siblings Research Consortium, an international network studying the earliest manifestations of ASD. A total of 1605 infants with an older autistic sibling were followed from early in life to 3 years, when they were classified as ASD or non-ASD. Hierarchical generalized linear modeling, with site as a random effect, was used to examine predictors of recurrence in families and calculate likelihood ratios. A total of 20.2% of siblings developed ASD, which is not significantly higher than the previously reported rate of 18.7%. Male infant sex and >1 older affected sibling were significant predictors of familial recurrence. Proband sex also influenced recurrence rates, with siblings of female probands significantly more likely to develop ASD than siblings of male probands. Race and maternal education were also associated with recurrence in families. The familial recurrence rate of ASD, as measured in infant sibling studies, has not changed appreciably since previous estimates were made in 2011. Younger siblings of autistic children, particularly those who are male, have an affected female sibling, multiple affected siblings, or are impacted by social inequities, should be closely monitored and promptly referred for diagnostic evaluation.

Analysis of a Chinese pedigree with Bw subtype due to a novel variant of α-1,3-N-acetylgalactosaminyltransferase gene

To explore the serological characteristics and genetic variant in a Chinese pedigree with Bw subtype. A 32-year-old female proband who had undergone prenatal examination on December 10, 2020 at the 960th Hospital of the PLA Joint Logistics Support Force and five members from her pedigree were selected as the study subjects. Peripheral blood samples were collected and subjected to ABO blood group phenotyping with serological methods and ABO blood group genotyping with fluorescent PCR. Genetic testing and haplotype analysis were carried out by direct sequencing of the entire coding region of the ABO gene in the proband and cloned sequencing of exons 1-7. The blood type serology of the proband showed Bw, and her ABO blood type genotype determined by fluorescence PCR was B/O. The direct sequencing results showed that the proband had matched the ABO*O.01.01/ABO*B.01 genotype and carried a c.1A>G variant. Cloned sequencing has confirmed the c.1A>G variant to have occurred in the ABO*B.01 allele. Family analysis revealed that the mother of the proband had an O blood type, her husband had a B phenotype, and her three children had a normal B blood type. DNA sequencing showed that the two sons of the proband had a genotype of ABO*B.01 and c.1A>G/ABO*B.01. The daughter of the proband was ABO*O.01.01/ABO*B.01, whilst her mother was ABO*O.01.01/ABO *O.01.02. The novel c.1A>G variant sequence has been registered with the database with a number MZ076785 1. The novel c.1A>G variant of exon 1 of α- 1,3 galactose aminotransferase gene probably underlay the reduced expression of B antigen in this pedigree.

NGS-Based Identification of Two Novel PCDH19 Mutations in Female Patients with Early-Onset Epilepsy.

Developmental and epileptic encephalopathy-9 (DEE9) is characterized by seizure onset in infancy, mild to severe intellectual impairment, and psychiatric features and is caused by a mutation in the PCDH19 gene on chromosome Xq22. The rare, unusual X-linked type of disorder affects heterozygous females and mosaic males; transmitting males are unaffected. In our study, 165 patients with epilepsy were tested by Next Generation Sequencing (NGS)-based panel and exome sequencing using Illumina technology. PCDH19 screening identified three point mutations, one indel, and one 29 bp-long deletion in five unrelated female probands. Two novel mutations, c.1152_1180del (p.Gln385Serfs*6) and c.830_831delinsAA (p.Phe277*), were identified and found to be de novo pathogenic. Moreover, among the three inherited mutations, two originated from asymptomatic mothers and one from an affected father. The PCDH19 c.1682C>T and c.1711G>T mutations were present in the DNA samples of asymptomatic mothers. After targeted parental testing, X chromosome inactivation tests and Sanger sequencing were carried out for mosaicism examination on maternal saliva samples in the two asymptomatic PCDH19 mutation carrier subjects. Tissue mosaicism and X-inactivation tests were negative. Our results support the opportunity for reduced penetrance in DEE9 and contribute to expanding the genotype-phenotype spectrum of PCDH19-related epilepsy.

Survival analysis and gender differences in hypertrophic cardiomyopathy proband patients referred for genetic testing

BackgroundHypertrophic cardiomyopathy (HCM) is believed to have low overall mortality rate, that could be influenced by gender, particularly among probands. We aimed to evaluate the survival rates and possible gender differences in a homogeneous cohort of HCM proband patients, referred for genetic testing, from the same geographical area, without differences in medical care access nor clinical referral pathways. Methodswe compared the mortality rates of a cohort of consecutive HCM probands referred for genetic testing (2000−2022), from a Spanish region (xxx1) with a centralized genetic testing pathway, with its control reference population by Ederer II method. Gender differences were analyzed. ResultsAmong the 649 HCM probands included in this study, there were significantly more men than women (61.3% vs 38.7, p < 0.05), with an earlier diagnosis (53.5 vs 61.1 years old, p < 0.05). Clinical evolution or arrhythmogenic HCM profile did no show no significant gender differences. Mean follow up was 9,8 years ±6,6 SD (9,9 ± 7 vs 9,6 ± 6,1, p = 0.59). No statistically significant differences in observed mortality, expected survival and excess mortality were found in the general HCM proband cohort. However, we found a significant excess mortality in female probands with HCM. No additional differences in analysis by genetic status were identified. ConclusionExpected survival in our HCM probands did not differ from its reference population. However, despite no gender differences in phenotype severity were identified, proband HCM women did present a diagnosis delay and worse mortality outcomes.

Genotype-phenotype analysis of Fabry disease caused by GLA gene variation in a pedigree

Objective: To investigate the clinical phenotype and genetic characteristics of patients with Fabry disease caused by a GLA variant, IVS4+919G>A. Methods: It was a prospective study. Fabry disease screening was conducted among high-risk population in Ninghai from October 2021 to August 2023. Those children with decreased α-galactosidase enzyme activity<2.40 μmol/(L·h) or elavated Lyso-GL-3 level>1.10 μg/L in dried blood spot (DBS) method underwent GLA genetic testing for diagnosis confirmation. Meanwhile, family screening was carried out. A proband and his family members diagnosed with Fabry disease were research subjects. The clinical and genetic characteristics of patients with Fabry disease caused by the GLA variant (IVS4+919G>A) were analyzed. Results: The female proband aged 9.8 years with pain in both lower limbs as the initial symptom was found to have a heterozygous GLA variant IVS4+919G>A among 102 patients. In family screening, there were 4 family members (proband's father, elder sister, elder male cousin and elder female cousin) with Fabry disease and a family member (proband's fifth aunt) with a GLA variant. Among these 4 diagnosed family members, the elder male cousin of the proband, a boy aged 13.2 years had a heterozygous GLA variant, IVS4+919G>A with intermittent pain in both lower limbs as the initial symptom. The proband's father had knee joint pain. The proband's elder sister had decreased vision and his elder female cousin had no obvious symptoms. The proband's fifth aunt with a GLA variant had decreased vision. Conclusions: High-risk screening in children and family screening are helpful for early diagnosis and treatment of Fabry disease. Neuropathic pain may be a early symptom in children with Fabry disease caused by the GLA variant, IVS4+919G>A.

Family analysis and literature study of hereditary hypophosphatemic rickets with hypercalciuria

BackgroundHereditary hypophosphatemia rickets with hypercalciuria (HHRH) is a rare autosomal recessive disorder characterised by reduced renal phosphate reabsorption leading to hypophosphataemia, rickets and bone pain. Here, we present a case of HHRH in a Chinese boy.Case presentationWe report a 11-year-old female proband, who was admitted to our hospital with bilateral genuvarum deformity and short stature. Computed Tomography (CT) showed kidney stones, blood tests showed hypophosphatemia, For a clear diagnosis, we employed high-throughput sequencing technology to screen for variants. Our gene sequencing approach encompassed whole exome sequencing, detection of exon and intron junction regions, and examination of a 20 bp region of adjacent introns. Flanking sequences are defined as ±50 bp upstream and downstream of the 5′ and 3′ ends of the coding region.The raw sequence data were compared to the known gene sequence data in publicly available sequence data bases using Burrows-Wheeler Aligner software (BWA, 0.7.12-r1039), and the pathogenic variant sites were annotated using Annovar. Subsequently, the suspected pathogenic variants were classified according to ACMG’s gene variation classification system. Simultaneously, unreported or clinically ambiguous pathogenic variants were predicted and annotated based on population databases. Any suspected pathogenic variants identified through this analysis were then validated using Sanger sequencing technology. At last, the proband and her affected sister carried pathogenic homozygous variant in the geneSLC34A3(exon 13, c.1402C > T; p.R468W). Their parents were both heterozygous carriers of the variant. Genetic testing revealed that the patient has anLRP5(exon 18, c.3917C > T; p.A1306V) variant of Uncertain significance, which is a rare homozygous variant.ConclusionThis case report aims to raise awareness of the presenting characteristics of HHRH. The paper describes a unique case involving variants in both theSLC34A3andLRP5genes, which are inherited in an autosomal recessive manner. This combination of gene variants has not been previously reported in the literature. It is uncertain whether the presence of these two mutated genes in the same individual will result in more severe clinical symptoms. This report shows that an accurate diagnosis is critical, and with early diagnosis and correct treatment, patients will have a better prognosis.

A female patient carrying a novel DMD mutation with non-random X-chromosome inactivation from a DMD family

ObjectiveTo analyze the clinical phenotype and genetic characteristics of a female proband carrying a novel mutation in the DMD gene with non-random X-chromosome inactivation in a large pedigree with pseudohypertrophic muscular dystrophy.MethodsClinical information of the female proband, her monozygotic twin sister, and other family members were collected. Potential pathogenic variants were detected with Multiplex Ligation-dependent Probe Amplification (MLPA) and whole-exome sequencing (WES). Methylation-sensitive restriction enzyme (HhaI) was employed for X-chromosome inactivation analysis.ResultsThe proband was a female over 5 years old, displayed clinical manifestations such as elevated creatine kinase (CK) levels and mild calf muscle hypertrophy. Her monozygotic twin sister exhibited normal CK levels and motor ability. Her uncle and cousin had a history of DMD. WES revealed that the proband carried a novel variant in the DMD (OMIM: 300,377) gene: NM_004006.3: c.3051_3053dup; NP_003997.2: p.Tyr1018*. In this pedigree, five out of six female members were carriers of this variant, while the cousin and uncle were hemizygous for this variant. X-chromosome inactivation analysis suggested non-random inactivation in the proband.ConclusionThe c.3051_3053dup (p.Tyr1018*) variant in the DMD gene is considered to be the pathogenic variant significantly associated with the clinical phenotype of the proband, her cousin, and her uncle within this family. Integrating genetic testing with clinical phenotype assessment can be a valuable tool for physicians in the diagnosis of progressive muscular dystrophies, such as Becker muscular dystrophy (BMD) and Duchenne muscular dystrophy (DMD).

Discovery and functional investigation of BMP4 as a new causative gene for human congenital heart disease.

Aggregating evidence highlights the strong genetic basis underpinning congenital heart disease (CHD). Here BMP4 was chosen as a prime candidate gene causative of human CHD predominantly because BMP4 was amply expressed in the embryonic hearts and knockout of Bmp4 in mice led to embryonic demise mainly from multiple cardiovascular developmental malformations. The aim of this retrospective investigation was to discover a novel BMP4 mutation underlying human CHD and explore its functional impact. A sequencing examination of BMP4 was implemented in 212 index patients suffering from CHD and 236 unrelated non-CHD individuals as well as the family members available from the proband carrying a discovered BMP4 mutation. The impacts of the discovered CHD-causing mutation on the expression of NKX2-5 and TBX20 induced by BMP4 were measured by employing a dual-luciferase analysis system. A new heterozygous BMP4 mutation, NM_001202.6:c.318T>G;p.(Tyr106*), was found in a female proband affected with familial CHD. Genetic research of the mutation carrier's relatives unveiled that the truncating mutation was in co-segregation with CHD in the pedigree. The nonsense mutation was absent from 236 unrelated non-CHD control persons. Quantitative biologic measurement revealed that Tyr106*-mutant BMP4 failed to induce the expression of NKX2-5 and TBX20, two genes whose expression is lost in CHD. The current findings indicate BMP4 as a new gene predisposing to human CHD, allowing for improved prenatal genetic counseling along with personalized treatment of CHD patients.

A novel MAPT variant (E342K) as a cause of familial progressive supranuclear palsy.

MAPT variants are a known cause of frontotemporal dementia and Parkinsonian syndrome, of which progressive supranuclear palsy syndrome (PSP) is a rare manifestation. To report a novel MAPT variant in a PSP pedigree with autosomal dominant inheritance pattern, and to produce a literature review of PSP patients with MAPT variants. A comprehensive clinical, genetic, and molecular neuroimaging investigation was conducted on a 61 years-old female proband diagnosed with PSP. We also collected the clinical presentation data and history of the patient's pedigree, and performed further genetic analysis of 4 relatives, from two generations, with and without symptoms. The proband exhibited typical clinical manifestation of PSP. A cranial MRI revealed midbrain atrophy, and an FDG-PET scan suggested hypo-metabolic changes in caudate nucleus, left prefrontal lobe, both temporal poles, and midbrain. 18F-florzolo-tau-PET revealed tau-protein deposits in the thalamus and brainstem bilaterally. A gene test by whole-exome sequencing identified a novel MAPT variant [NM_005910.6, exon 11, c.1024G > A (p.E342K)], and the same variant was also identified in one affected relative and one asymptomatic relative, a probable pre-symptomatic carrier. The PSP pedigree caused by the novel MAPT (E342K) variant, expanded the mutational spectrum of MAPT.

Familial uveal melanoma and other tumors in 25 families with monoallelic germline MBD4 variants.

Monoallelic germline MBD4 pathogenic variants were recently reported to cause a predisposition to uveal melanoma, associated with a specific tumor mutational signature and good response to immunotherapy. Monoallelic tumor pathogenic variants have also been described in brain tumors, breast cancers, and myxofibrosarcomas, whereas biallelic germline MBD4 pathogenic variants have been involved in a recessive hereditary adenomatous polyposis and a specific type of acute myeloid leukemia. We analyzed MBD4 for all patients with a diagnosis of uveal melanoma at Institut Curie since July 2021 and in the 3240 consecutive female probands explored at the Institut Curie for suspicion of predisposition to breast cancer between July 2021 and February 2023. We describe 25 families whose probands carry a monoallelic germline pathogenic variant in MBD4. Eighteen of these families presented with uveal melanoma (including a case patient with multiple uveal melanoma), and 7 families presented with breast cancer. Family histories showed the first familial case of uveal melanoma in monoallelic MBD4 pathogenic variant carriers and other various types of cancers in relatives, especially breast, renal, and colorectal tumors. Monoallelic MBD4 pathogenic variant may explain some cases of familial and multiple uveal melanoma as well as various cancer types, expanding the tumor spectrum of this predisposition. Further genetic testing in relatives combined with molecular tumor analyses will help define the tumor spectrum and estimate each tumor's risk.

Clinical and Laboratory Characteristics of Individuals Aged ≤17 Years With Homeostatic Iron Regulator (HFE) p.C282Y Homozygosity, a Common Hemochromatosis Genotype.

Background Characteristics of cohorts of individuals aged ≤17 years with homeostatic iron regulator (HFE) p.C282Y (rs1800562) homozygosity, a common hemochromatosis genotype, have not been reported. Methodology We retrospectively tabulated characteristics of white individuals aged ≤17 years with p.C282Y homozygosity. Individuals were not recruited for this study. We defined transferrin saturation (TS) >45%, serum ferritin (SF) >300 µg/L (M) and >200 µg/L (F) as elevated and liver iron grade 3 or 4, hepatic iron index >1.9 µmol Fe/g dry weight liver/y, and phlebotomy-mobilized iron >1.0 g (M) and >0.3 g (F) as increased. Results There were nine males and six females with a mean age of 12 ± 4 years (range = 5-17 years). The mean age of 10 probands (13 ± 3 years) was greater than that of five individuals discovered in family studies (9 ± 4 years) (p = 0.0403). Presenting manifestations of probands included fatigue/lethargy (5), elevated TS (2), and polycystic ovary syndrome, amenorrhea, and diabetes (2). In 15 individuals, the mean TS was 65 ± 23%. TS was elevated in 11(73.3%) individuals aged 5-17 years. In 14 individuals, the mean SF was 262 ± 289 µg/L. SF was elevated and liver and phlebotomy-mobilized iron were increased in two male and three female probands aged 13-16 years (5/14 individuals, 35.7%). No individual had advanced hepatic fibrosis, arthropathy, hypogonadism, cardiomyopathy, or hyperpigmentation. Conclusions We conclude that five individuals aged 13-16 years (5/14 individuals, 35.7%) had increased liver and phlebotomy-mobilized iron.

Dissociable influences of maternal vs paternal Alzheimer’s risk on neurocognitive and cardiovascular health in men and women

AbstractBackgroundParental history of sporadic Alzheimer’s disease (AD) is considered a prime risk factor since at least the late 1980s. Routinely used clinical samples of at‐risk individuals (8‐16 subjects) may conceal weaker population‐based effects, especially those of paternal inheritance. We performed a phenome‐wide examination of the dissociable influences of maternal vs. paternal AD risk on male vs. female probands in the largest single‐site family‐based at‐risk AD cohort: PREVENT‐AD.MethodWe built sex‐specific PLS‐regression models in which the APOE genotypes (e.g., ɛ3/3, ɛ3/4, ɛ3/2) were estimated based on ∼1,000 patient visits, each covering ∼260 risk indicators, to derive three APOE‐driven intermediate phenotypes (IPs). We examined how much the three IPs vary with regard to sex and maternal vs. paternal AD lineage across the phenome. We assessed the sex‐specific and lineage‐specific variation of the IPs over a 4‐year follow‐up period. Lastly, we examined how matri‐ vs. patrilinear AD risk captured by the IPs were expressed in AD‐vulnerable brain structures.ResultAcross IPs, we linked patrilinear AD risk to verbal‐numerical cognition and cardiovascular health in males. In contrast, we linked matrilinear AD risk to memory performance in both sexes. Over time, the mean difference in cognitive performance decreases with regard to sex but increases with regard to AD lineage. Cis‐ and trans‐generational sex effects in neocortex subregions (e.g., mPFC, PCu) were captured by the first and second IPs, respectively. The third IP mainly captured trans‐generational sex effects in hippocampus subregions (e.g., CA1, CA4).ConclusionWe uncovered IPs of AD susceptibility differently expressed in male and female probands and affected by the diagnosed parent’s sex. Maternal inheritance highlighted memory performance in both sexes, whereas paternal inheritance was particularly linked to cardiovascular health in males. The inheritance of the IPs was reflected in the brain structure at both superficial and deeper layers of the cortex. As the first study of its kind, our cross‐generational analysis of matri‐ vs. patrilinear AD risk bridges the epidemiological and clinical literature by leveraging the power of ∼1,000 patient visits. Our completely data‐driven framework ultimately dissociated phenotypes of maternal and paternal AD risk single‐handedly expressed in male and female probands.

Rare A360T Mutation Alters GSK3β(Ser9) Binding in the Cytosolic Loop of Presenilin 1, Influencing β-Catenin Nuclear Localization and Pro-Death Gene Expression in Alzheimer’s Disease Case

Presenilin 1 (PS1) forms, via its large cytosolic loop, a trimeric complex with N-cadherin and β-catenin, which is a key component of Wnt signaling. PS1 undergoes phosphorylation at 353 and 357 serines upon enhanced activity and elevated levels of the GSK3β isoform. PS1 mutations surrounding these serines may alter the stability of the β-catenin complex. Such mutations are found in some cases of familial early-onset Alzheimer’s disease (fEOAD), but their functional impact remains obscure. One of such variants of PS1, the A360T substitution, is located close to GSK3β-targeted serine residues. This variant was recently demonstrated in the French population, but more detail is needed to understand its biological effects. To assess the significance of this variant, we employed functional studies using a fibroblast cell line from an Alzheimer’s disease case (a female proband) carrying the A360T mutation. Based on functional transcriptomic, cellular, and biochemical assays, we demonstrated atypically impaired β-catenin/GSK3β signaling in the A360T patient’s fibroblasts. In detail, this was characterized by a decreased level of active cytosolic β-catenin and bound by PS1, an increased level of nuclear β-catenin, an increased level of inhibited GSK3β phosphorylated on Ser9, and enhanced interaction of GSK3β(Ser9) with PS1. Based on the transcriptomic profile of the A360T fibroblasts, we proposed a dysregulated transcriptional activity of β-catenin, exemplified by increased expression of various cyclin-dependent kinases and cyclins, such as cyclin D1, potentially inducing neurons’ cell cycle re-entry followed by apoptosis. The A360T cells did not exhibit significant amyloid pathology. Therefore, cell death in this PS1 cytosolic loop mutation may be attributed to impaired β-catenin/GSK3β signaling rather than amyloid deposition per se. We further estimated the biological and clinical relevance of the A360T variant by whole exome sequencing (WES). WES was performed on DNA from the blood of an A360T female proband, as well as an unrelated male patient carrying the A360T mutation and his mutation-free daughter (both unavailable for the derivation of the fibroblast cell lines). WES confirmed the highest-priority AD causality of the A360T variant in PS1 and also profiled the pathways and processes involved in the A360T case, highlighting the greatest importance of altered Wnt signaling.

Height of non-Hispanic white adults with homeostatic iron regulator HFE genotypes p.C282Y/p.C282Y and wt/wt.

We sought to evaluate height in white adults with hemochromatosis. We analyzed the height of (1) post-screening examination participants with HFE p.C282Y/p.C282Y (rs1800562) and wt/wt (absence of p.C282Y and p.H63D (rs1799945)) and (2) referred hemochromatosis probands with p.C282Y/p.C282Y. There were 762 participants (270 p.C282Y/p.C282Y, 492 wt/wt; 343 men, 419 women) and 180 probands (104 men, 76 women). Median height of male participants with p.C282Y/p.C282Y or wt/wt was 177.8 cm. Median height of female participants was greater in those with p.C282Y/p.C282Y than wt/wt (165.1 cm vs 162.6 cm, respectively; p = 0.0298). Median height of p.C282Y/p.C282Y participants and probands was the same (men 177.8 cm; women 165.1 cm). Regressions on height of male and female participants revealed no associations with HFE genotype and inverse and positive associations with age and weight, respectively. Height of female participants was positively and inversely associated with transferrin saturation and serum ferritin, respectively. Regressions on height of male and female probands revealed positive associations with weight. The height of men with HFE p.C282Y/p.C282Y and wt/wt does not differ significantly. The height of female participants was greater in those with p.C282Y/p.C282Y than wt/wt. We found no independent association of HFE genotype with the height of men or women.

Safe use of the ketogenic diet in an infant with microcephaly, epilepsy, and diabetes syndrome: a case report

BackgroundMicrocephaly, epilepsy, and diabetes syndrome (MEDS) is a rare syndromic form of monogenic diabetes caused by bi-allelic loss of function mutations in IER3IP1. In vitro studies have shown that loss of IER31P leads to apoptosis in both neurons and pancreatic β-cells. Simultaneous management of seizures and diabetes is challenging in patients with MEDS. We present the challenges and successes in the use of ketogenic diet in an infant with insulinopenic diabetes.Case presentationOur term female proband presented at 2 months of age with new onset multifocal seizures followed by the onset of infantile spasms (IS) at 4 months of age. An epilepsy gene panel identified bi-allelic variants, c.239T > G (p.Leu80*) and c.2T > A (initiator codon), in IER3IP1 that were subsequently shown to be inherited in trans. Following initiation of steroid therapy for IS, the patient developed clinically apparent insulin requiring diabetes. Her epilepsy was ultimately refractory to multiple antiseizure medications, thus the ketogenic diet (KD) was initiated. We were able to successfully titrate to a therapeutic KD ratio of 3:1 and maintain a ketotic state without diabetic ketoacidosis (DKA). With intercurrent illnesses, however, the patient had rapid decompensation and mild DKA due to delays in treatment, and for this reason, KD was discontinued after 5 months.ConclusionsWe report two novel IER31P1 mutations in a patient with MEDS and the successful management of the cooccurring conditions of IS and insulinopenic diabetes with the KD. Our experience underscores the importance of careful monitoring during KD as our patient had DKA more easily when on the KD.

Clinical, radiological, biochemical and molecular characterization of a new case with multiple mitochondrial dysfunction syndrome due to IBA57: Lysine and tryptophan metabolites as potential biomarkers

Iron‑sulfur clusters (FeS) are one of the most primitive and ubiquitous cofactors used by various enzymes in multiple pathways. Biosynthesis of FeS is a complex multi-step process that is tightly regulated and requires multiple machineries. IBA57, along with ISCA1 and ISCA2, play a role in maturation of [4Fe-4S] clusters which are required for multiple mitochondrial enzymes including mitochondrial Complex I, Complex II, lipoic acid synthase, and aconitase. Pathogenic variants in IBA57 have been associated with multiple mitochondrial dysfunctions syndrome 3 (MMDS3) characterized by infantile to early childhood-onset psychomotor regression, optic atrophy and nonspecific dysmorphism. Here we report a female proband who had prenatal involvement including IUGR and microcephaly and developed subacute psychomotor regression at the age of 5 weeks in the setting of preceding viral infection. Brain imaging revealed cortical malformation with polymicrogyria and abnormal signal alteration in brainstem and spinal cord. Biochemical analysis revealed increased plasma glycine and hyperexcretion of multiple organic acids in urine, raising the concern for lipoic acid biosynthesis defects and mitochondrial FeS assembly defects. Molecular analysis subsequently detected compound heterozygous variants in IBA57, confirming the diagnosis of MMDS3. Although the number of MMDS3 patients are limited, certain degree of genotype-phenotype correlation has been observed. Unusual brain imaging in the proband highlights the need to include mitochondrial disorders as differential diagnoses of structural brain abnormalities. Lastly, in addition to previously known biomarkers including high blood lactate and plasma glycine levels, the increase of 2-hydroxyadipic and 2-ketoadipic acids in urine organic acid analysis, in the appropriate clinical context, should prompt an evaluation for the lipoic acid biosynthesis defects and mitochondrial FeS assembly defects.