Positive Genetic Test Research Articles

Pathogenic Variant Frequencies in Hereditary Haemorrhagic Telangiectasia Support Clinical Evidence of Protection from Myocardial Infarction.

Hereditary haemorrhagic telangiectasia (HHT) is a vascular dysplasia inherited as an autosomal dominant trait, due to a single heterozygous loss-of-function variant, usually in ACVRL1 (encoding activin receptor-like kinase 1 [ALK1]), ENG (encoding endoglin [CD105]), or SMAD4. In a consecutive single-centre series of 37 positive clinical genetic tests performed in 2021-2023, a skewed distribution pattern was noted, with 30 of 32 variants reported only once, but ACVRL1 c.1231C>T (p.Arg411Trp) identified as the disease-causal gene in five different HHT families. In the same centre's non-overlapping 1992-2020 series where 110/134 (82.1%) HHT-causal variants were reported only once, ACVRL1 c.1231C>T (p.Arg411Trp) was identified in nine further families. In a 14-country, four-continent HHT Mutation Database where 181/250 (72.4%) HHT-causal variants were reported only once, ACVRL1 c.1231C>T (p.Arg411Trp) was reported by 12 different laboratories, the adjacent ACVRL1 c.1232G>A (p.Arg411Gln) by 14, and ACVRL1 c.1120C>T (p.Arg374Trp) by 18. Unlike the majority of HHT-causal ACVRL1 variants, these encode ALK1 protein that reaches the endothelial cell surface but fails to signal. Six variants of this type were present in the three series and were reported 6.8-25.5 (mean 8.9) times more frequently than the other ACVRL1 missense variants (all p-values < 0.0039). Noting lower rates of myocardial infarction reported in HHT, we explore potential mechanisms, including a selective paradigm relevant to ALK1's role in the initiating event of atherosclerosis, where a plausible dominant negative effect of these specific variants can be proposed. In conclusion, there is an ~9-fold excess of kinase-inactive, cell surface-expressed ACVRL1/ALK1 pathogenic missense variants in HHT. The findings support further examination of differential clinical and cellular phenotypes by HHT causal gene molecular subtypes.

Patient experiences in receiving telegenetics care for inherited cardiovascular diseases.

Telegenetics played an important role in providing genetic services to patients during the COVID-19 pandemic. In particular, at our institution, it enabled us to expand our genetic counseling and testing services to non-local family members of patients outside of our prior catchment area. However, as telegenetics continues to be utilized even as social distancing is no longer required, further information is needed regarding the impact of this modality on patient experience within cardiogenetics. This study qualitatively explored the experiences of 12 genotype positive individuals who underwent genetic counseling and testing via telegenetics during the first 22months of the COVID-19 pandemic and compared the experiences of local vs. non-local patients. Both local and non-local participants discussed similar benefits and drawbacks to the use of technology in telegenetics and overall found the use of telegenetics and at-home genetic testing to be convenient. Both groups also noted having to make changes in their daily lives and future planning as a consequence of the positive genetic testing results. However, access to follow-up care differed between local and non-local participants, with more local participants having scheduled and attended appointments with the appropriate medical providers compared to non-local participants. Supplying non-local patients access to remote cardiogenetic testing may therefore require careful consideration in how to ensure proper follow-up care for genotype positive patients and may necessitate the involvement of national professional or patient-centered organizations to help streamline the referral process.

A systematic review and meta-analysis of sex differences in clinical outcomes of hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is recognized as the most prevalent form of genetic cardiomyopathy, and recent investigations have shed light on the existence of sex disparities in terms of clinical presentation, disease progression, and outcomes. This study aimed to systematically review the literature and perform a meta-analysis to comprehensively compare the clinical outcomes between female and male patients with HCM. A thorough search was conducted in databases including PubMed, Embase, Cochrane Library, and Web of Science, encompassing literature from inception until June 2023. The primary endpoints examined were: (1) all-cause mortality; (2) an arrhythmic endpoint comprising sudden cardiac death (SCD), sustained ventricular tachycardia, ventricular fibrillation, or aborted SCD; and (3) a composite endpoint incorporating either (1) or (2), in addition to hospitalization for heart failure or cardiac transplantation. Pooled estimates were derived using a random-effects meta-analysis model. The analysis encompassed a total of 29 observational studies, involving 44,677 patients diagnosed with HCM, of which 16,807 were female. Baseline characteristics revealed that the female group exhibited an advanced age [55.66 ± 0.04 years vs. 50.38 ± 0.03 years, pooled mean difference (MD) = 0.31, 95% CI: 0.22-0.40, p = 0.000, I2 = 88.89%], a higher proportion of New York Heart Association class III/IV patients [pooled odds ratio (OR) = 1.94, 95% CI: 1.55-2.43, p = 0.000, I2 = 85.92%], and a greater prevalence of left ventricular outflow tract gradient greater than or equal to 30 mmHg (pooled OR = 1.48, 95% CI: 1.27-1.73, p = 0.000, I2 = 68.88%) compared to the male group. The female group were more likely to have a positive genetic test (pooled OR = 1.27, 95% CI: 1.08-1.48, p = 0.000, I2 = 42.74%) and to carry the myosin heavy chain beta 7 mutation (pooled OR = 1.26, 95% CI: 1.04-1.54, p = 0.020, I2 = 0.00%) compared to the male group. Female sex exhibited a significant association with increased risks of all-cause mortality (pooled OR = 1.62, 95% CI: 1.38-1.89, p = 0.000, I2 = 72.78%) and the composite endpoint (pooled OR = 1.47, 95% CI: 1.20-1.79, p = 0.000, I2 = 84.96%), while no substantial difference was observed in the arrhythmic endpoint (pooled OR = 1.08, 95% CI: 0.87-1.34, p = 0.490, I2 = 55.48%). The present findings suggest that female patients with HCM tend to experience poorer clinical outcomes. It is imperative to critically reevaluate disease definitions and enhance awareness to mitigate delays in the diagnosis and treatment of HCM in women, thereby fostering equitable healthcare practices. https://www.crd.york.ac.uk/, PROSPERO (CRD42023431881).

Sample Loading - The Critical Step of Biopsy

Failed or poor sample loading following trophectoderm cells sampling can ruin all efforts made before by causing DNA amplification failure, false positive or false negative genetic testing results, and false mosaic reports. In this lecture, all steps involved in the sample loading procedure will be addressed and discussed in detail, including solutions needed, identification, PCR tube setup, washing, and loading.

Self-Sustainability with Therapeutic Phlebotomy, a Solution to the National Blood Crisis?

CONCLUSION Hereditary hemochromatosis (HH) is a genetic condition associated with iron overload in the human body. The mainstay of treatment remains therapeutic phlebotomy. On August 1st, 2022, the American Red Cross approved using blood obtained from therapeutic phlebotomy for transfusion. While normal individuals can donate blood only as often as once in 56 days, individuals with HH can have phlebotomy as often as once weekly. Utilizing the blood collected from these patients could be a significant resource to mitigate the shortage of blood needed for transfusion. We aimed to quantify the number of units of blood removed by therapeutic phlebotomy from individuals with HH and assess its potential contribution to total units of blood required in a community hospital for two years (2021 and 2022). We retrospectively reviewed electronic medical records of adult individuals who underwent therapeutic phlebotomy at Saint Vincent Hospital between January 1, 2021, and December 31, 2022. Patients with hereditary hemochromatosis were identified based on a positive genetic test for HFE gene mutations. We collected data including gender, race, age at diagnosis, and the number of units of blood removed from patients during the study period. The total number of units transfused in the in-patient care services and operating room was obtained. A descriptive statistic was performed using R version 4.2.2 statistics software. A total of 112 patients received therapeutic phlebotomy over two years (2021 and 2022) of whom 65% (N=73) had a diagnosis of HH. A majority of the patients were males (60%, 44/73) and were non-Hispanic/Latino (85%, 62/73). The mean age at diagnosis of HH was 62 [standard deviation (SD): 17] years. The median number of units of blood removed by phlebotomy per patient with HH was 3 (2-5), the annual distribution is as displayed in Table 1. A total of 504 units of whole blood was removed through therapeutic phlebotomy from 73 patients during the study period. The total requirement for blood transfusion across all the departments in the hospital was 6065 units (2,733 units in 2021 and 3,332 units in 2022). The total number of units removed through therapeutic phlebotomy in HH patients represented 8.31% (504/6065 Units) and 82.49% (504/611 Units) of total units of blood requirement for the entire hospital and operating room respectively (Table 2). The units of blood removed through therapeutic phlebotomy of patients with HH, could potentially help sustain 8.31% of total blood requirement of the hospital. Primarily, over 82% of the demand from the operating room could be fulfilled if the entirety of the blood from therapeutic phlebotomy were to be transfused. Overcoming technical challenges in utilizing the blood from therapeutic phlebotomy for transfusion in routine clinical practice could help mitigate the national blood crisis and aid in self-sustainability of blood products at a community level. Our study highlights the need for broader efforts to create awareness and incentivizing re-utilization of blood obtained from therapeutic phlebotomy.

Characterizing Decision-Making Surrounding Exercise in ARVC: Analysis of Decisional Conflict, Decisional Regret, and Shared Decision-Making.

Limiting high-intensity exercise is recommended for patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) due to its association with penetrance, arrhythmias, and structural progression. Guidelines recommend shared decision-making (SDM) for exercise level, but there is little evidence regarding its impact. Therefore, we sought to evaluate the extent and implications of SDM for exercise, decisional conflict, and decisional regret in patients with ARVC and at-risk relatives. Adults diagnosed with ARVC or with positive genetic testing enrolled in the Johns Hopkins ARVC Registry were invited to complete a questionnaire that included exercise history and current exercise, SDM (SDM-Q-9), decisional conflict, and decisional regret. The response rate was 64.8%. Two-thirds of participants (68.0%, n=121) reported clinically significant decisional conflict regarding exercise at diagnosis/genetic testing (DCS [decisional conflict scale]≥25), and half (55.1%, n=98) in the past year. Prevalence of decisional regret was also high with 55.3% (n=99) reporting moderate to severe decisional regret (DRS [decisional regret scale]≥25). The extent of SDM was highly variable ranging from no (0) to perfect (100) SDM (mean, 59.6±25.0). Those diagnosed in adolescence (≤age 21) reported significantly more SDM (P=0.013). Importantly, SDM was associated with less decisional conflict (ß=-0.66, R2=0.567, P<0.01) and decisional regret (ß=-0.37, R2=0.180, P<0.001) and no difference in vigorous intensity aerobic exercise in the 6 months after diagnosis/genetic testing or the past year (P=0.56; P=0.34, respectively). SDM is associated with lower decisional conflict and decisional regret; and no difference in postdiagnosis exercise. Our data thus support SDM as the preferred model for exercise discussions for ARVC.

Disease penetrance in genotype-positive relatives from families with dilated cardiomyopathy

Abstract Background Genetic testing of patients with dilated cardiomyopathy (DCM) results in identification of a causative gene variant in around 19-37% of individuals [1]. Serial clinical assessment of relatives found to carry genetic variants is recommended, but there are no data to guide screening intervals or to better understand the influence of age, sex and genotype on disease expression. Purpose To evaluate the trajectory of disease development in clinically unaffected relatives with a positive genetic test. Methods Families with a likely pathogenic or pathogenic variant in DCM related genes were identified from the database at a cardiomyopathy unit. Families were included only where phenotypes were consistent with DCM or hypokinetic non-dilated cardiomyopathy [2]. Consecutive relatives from these families were retrospectively recruited where they had tested positive for the familial genetic variant and were clinically unaffected at baseline evaluation. Incidence rates of disease penetrance during follow-up were stratified by sex and genotype. Results 131 relatives (59 male (45%) with median age 28.6 [21.5 – 42.0] years at first evaluation) representing 75 families were included. The most prevalent genotypes were DSP (46/131, 35.1%), TTN (32/131, 24.4%) , LMNA (22/131, 16.8%), RBM20 (14/131, 10.7%) and BAG3 (8/131, 6.1%). The overall incident rate of phenotype development during follow-up was 11.6 [8.9 – 14.2] per 100 person years and rates were significantly different between males and females (16.1 versus 8.8 per 100 person-years, log-rank p value = 0.006; Figure 1). LMNA variant-carriers had the highest incidence rate of disease penetrance at 17.7 [9.8 – 25.7] per 100 person-years and disease penetrance occurred at a younger age than DSP and TTN variant-carriers (Figure 2). Conclusions Disease development during follow-up is common in genotype-positive relatives, particularly in males and in LMNA variant-carriers. Genotype-positive relatives should be rescreened at least once each year.Figure 1Figure 2

Arrhythmic risk stratification in patients with left ventricular ring-like scar

Abstract Background Myocardial fibrosis assessment with late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR) has recently emerged as an independent predictor of major adverse events in patients with non-ischemic cardiomyopathy. Several studies have examined different locations and extension degrees of LGE, and the so called "ring-like pattern" has been related with an increased incidence of ventricular arrhythmias, in patients with dilated cardiomyopathy (DCM), but also in patients with preserved systolic function. Purpose To describe clinical, electrocardiographic, echocardiographic, CMR and genetic features of the left ventricular (LV) ring-like scar phenotype and to evaluate which characteristics may be associated with the risk of sudden cardiac death (SCD). Methods Patients diagnosed with LV ring-like scar were identified at 6 referral Centres. Diagnosis was based on: 1) ring-like LGE LV pattern, defined as at least 3 contiguous segments with subepicardial/midwall LGE in the same slice with or without fatty infiltration; or 2) pathology examination of explanted hearts/autoptic cases suffering from sudden cardiac death (SCD). Moreover, patients must have an additional inclusion criterion: a positive genetic test, or ≥1 patient in the same family with an ascertained cardiomyopathy. Major adverse arrhythmic cardiac events (MAACE), defined as a composite of SCD, aborted SCD, and sustained ventricular tachycardia (SVT), were the primary study endpoint. Results The final cohort comprised 129 patients (male 59.7%, median age at diagnosis 44 years). During a median follow-up of 3.4 years (IQR 1.2 – 64.), MAACE occurred in 31 patients (24%). Nearly 70% of the patients had a likely pathogenic/pathogenic mutation, mostly in desmoplakin (DSP) and filamin-C (FLNC) genes (65% and 19%, respectively). Sex, QRS width, and LGE in LV anterior wall and/or apex, were the only independent predictors of the outcome events (HR: 0.329, 95% CI: 0.119-0.916, P = 0.033; HR: 1.036, 95% CI 1.019-1.053, P &amp;lt; 0.001; HR 4.270, 95% CI 1.337-13.630, P = 0.014, respectively). A significant interaction between sex and LGE in anterior wall/apex was observed, being this regions associated with MAACE only in male patients (p for interaction = 0.033). Although related to the arrhythmic endpoint at the Kaplan-Meier survival curves, neither DCM echocardiographic phenotype, nor LV ejection fraction ≤35% remained statistically associated to MAACE at the multivariate analysis. Age, genetic mutations, right ventricular involvement, proband status, LV-LGE extension (number of segments) were not statistically related to the study endpoint. Conclusions In this selected cohort of patients with LV ring-like scar and either a genetic test or family history, malignant arrhythmic events were predicted by male sex, QRS width and LGE in anterior wall and/or apex.Graphical Abstract

Retrospective analysis of confirmed cases of pulmonary veno-occlusive disease: a single tertiary referral center study

Abstract Background Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary hypertension that primarily results in intimal fibrosis of the pulmonary venules and veins, the venous lesions are often associated with changes in interlobular septa, lung parenchyma, and pulmonary arterioles and arteries. Purpose We sought to study the clinical characteristics of patients with confirmed PVOD at a single large referral center. Methods We retrospectively reviewed data from a total of 675 patients with pulmonary hypertension (identified by ICD codes or search of text) from 2017 and 2022 from a database obtained from electronic medical records at our institution. Patients with group 2 pulmonary hypertension were excluded. Only 29 cases were confirmed by histology or genetic testing. Results Out of the 29 patients confirmed with PVOD, 28 (96.5%) had a characteristic histology (lung biopsy (55.1%), explanted lung for transplant (27.5%) and autopsy (13.7%)) and 1 (3.4%) had a positive genetic test for EIF2AK4 biallelic mutation. The age at diagnosis was 53±16 years, 14 (48.2%) were men, 2 (6.8%) had systemic scleroderma, 2 (6.8%) had psoriasis, 2 (6.8%) were exposed to cytotoxic agents, 16 (55.1%) were smokers and 2 (6.8%) had a family history of pulmonary hypertension. All patients had computed tomography of the chest but only 12 (41.3%) had all 3 typical features found in PVOD (ground glass opacities, interlobular septal thickening, and lymphadenopathy). The most common feature was interlobular septal thickening in 26 (89.6%), followed by ground glass opacities present in 25 (86.2%) and lymphadenopathy in 12 (41.3%) of the patients. At diagnosis, mean pulmonary artery pressure was 45±15 mmHg and pulmonary vascular resistance was 9±6 WU. The median DLCO was 41 (34-58) %. On echocardiogram, 14 (48.2%) had severely enlarged right ventricle (RV), RV function was ≥moderately reduced in 17 (58.6%), RV systolic pressure was 63±20 mmHg and 6 (20.6%) had pericardial effusion. Out of 21 (72.4%) patients who received pulmonary vasodilators, 4 (13.7%) received single agent. 10 (34.4%) received 2 agents, 6 (20.6%) 3 agents, and 1 (3.4%) received 4 agents. 35.7% of these treated patients reported an improvement or initial worsening of symptoms with subsequent improvement afterwards. 18 (62%) patients with PVOD died, 12 (41.3%) had a lung transplant and 6 (20.6%) were still alive without the transplant until the day data was collected. Mean duration from diagnosis to death and lung transplantation was 446 ± 405 days and 274±479 days respectively. Conclusion PVOD is a rare and lethal cause of pulmonary hypertension. When suspected, a trial of medical therapy should be initiated carefully. The evaluation for lung transplant should be considered early given its high mortality.

Abstract 17577: Cardiomyopathy With Positive ATTR Mutation but Negative Tc-PYP Scan: A Conundrum

Background: Cardiac amyloidosis (CA) is a Hypertrophic Cardiomyopathy (HCM) mimic. Technetium labeled pyrophosphate (Tc-PYP) scan provides a rapid &amp; non-invasive means for identifying ATTR-type CA with 99% sensitivity and specificity. We present 2 patients who were referred to HCM clinic but were found to have genetic testing positive for hTTR. In both cases, Tc-PYP scan was negative. Case Presentation: Outlined in Figure 1. Discussion: Both cases present a diagnostic and management dilemma. Neither of these two patients can be strictly considered asymptomatic carriers of the ATTR gene as both had phenotypic expression in the form of cardiomyopathy &amp; massive LVH on imaging. Yet, in both Tc-PYP scan was negative. Neither had the ATTR mutations (Phe64Leu and Val30Met) that have reported association with negative Tc-PYP scan. Another possibility is early CA, which maybe rarely associated with negative Tc-PYP scan. Patient 1 refused endomyocardial biopsy, so early CA remains on the differential for her. Patient 2 had a negative endomyocardial biopsy. Her case is unique due to history of liver transplant 20 years prior to presentation making phenotypic CA less likely, but not impossible as there have been prior reports of cardiac disease progressing even after liver transplantation in familial ATTR. She also had tacrolimus exposure, which is known to cause LVH in rare cases. Both patients had hypertension, which could have also contributed to LVH. This case series serves to highlight the importance of maintaining a broad differential diagnosis in patients undergoing evaluation for HFpEF and severe LVH, particularly in cases of positive genetic testing but negative PYP scan for CA. From a management standpoint, it is unclear if early initiation of tafamidis might have a role in preventing cardiomyopathy progression in such patients with diagnostic uncertainty &amp; ongoing concern for early CA.

Abstract 017: Rapid Progression Of Microhemorrhage In A Patient With An Atypical CADASIL Variant

Introduction CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is a rare inherited disorder in which thickening occurs in the walls of small and medium‐sized blood vessels, which results in decreased cerebral blood delivery. CADASIL is most often established as a diagnosis with identification of a heterozygous pathogenic variant of the NOTCH3 gene by way of molecular genetic testing. In this abstract we identify an atypical presentation of CADASIL with a heterozygous pathologic variant of the HTRA1 gene. This case is unusual in its late onset, as the disease typically presents in the third to fourth decade of life. Additionally, the prevalence of microbleeds in CADASIL typically correlates with patient age. Methods Electronic charts of a patient with recurrent strokes and positive genetic testing were reviewed. Results A 63‐year‐old right‐handed African American male with hypertension, hyperlipidemia, diabetes mellitus, and a history of cerebrovascular disease and cervical myelopathy initially presenting in 2020 lower extremity weakness and progressive apraxia of speech. He had a documented history of transient‐ischemic attack and was noted to have undergone progressive cognitive decline. His presentation raised concern for etiology such as vasculitis or multiple sclerosis and prompted a genetic workup, which was obtained on outpatient follow‐up. The patient presented several more times emergently with similar symptoms that included the reoccurrence and progression of his spastic lower extremity weakness as well as the development of a pseudo‐bulbar affect. Initial MRI brain demonstrated areas of DWI hyperintensity scattered throughout the bilateral hemispheres without ADC correlation. Post‐contrast T2 sequencing demonstrated hyperintensities in the callosal splenium and left centrum semiovale. Genetic testing consisting of Hereditary Cerebral Small Vessel Disease and Hereditary Spastic Paraplegia panels through Invitae were obtained. The first panel evaluates 10 genes for variants which are associated with hereditary forms of cerebral small vessel disease, encompassing those conditions in which small arteries, arterioles, venules, and capillaries of the brain are compromised. The Hereditary Cerebral Small Vessel Disease genetic panel resulted in the positive identification of a likely‐pathogenic variant of the HTRA1 gene, which is associated with CADASIL 2. The Hereditary Spastic Paraplegia genetic panel was unremarkable, as were CSF studies obtained for evaluation of a demyelinating or inflammatory cause. Repeat MRI obtained twice more over the patient’s repeated presentations and demonstrated a large interval increase in areas of low‐signal gradient echo over the course of approximately three months, which represented an evolution in the number of microhemorrhages beyond what would be expected in such a short period of time. Conclusion Scientific literature describes the prevalence of microhemorrhages in CADASIL to be somewhere between 38‐75%. However, there have been few studies which detail such a rapid progression of microhemorrhages in this patient population as well as such a late progression of the disease. Our case demonstrates a unique presentation of CADASIL and provides a remarkable example of rapid, late‐in‐life disease presentation. Further research is needed to elucidate and characterize disease leading to early diagnosis and management.

The National Israeli Registry for Oculo-Pharyngeal Muscular Dystrophy (IsrO-PMD): rationale and design

BackgroundOculo-pharyngeal muscular dystrophy (OPMD) is a rare disease, caused by trinucleotide repeat expansion in the PABPN1 gene, inherited in an autosomal dominant (AD) manner. Its main features are eyelid ptosis and dysphagia, which manifest at the end of the fifth decade of life. Other symptoms include proximal muscle weakness and bulbar muscle weakness. Although OPMD is prevalent worldwide, a higher prevalence has been reported in the Jewish population from Bukhara. Currently, no specific drugs are available for OPMD.ObjectiveOur National Israeli Registry for Oculo-Pharyngeal Muscular Dystrophy (IsrO-PMD) study aims to provide a framework for the assessment and documentation of the natural history of the diseases as we as a multi-disciplinary management of patients with OPMD. The IsrO-PMD may be the cornerstone of future clinical trials for novel therapies for OPMD.MethodsThe IsrO-PMD is a national prospective registry that involves non-interventional data collection based on the Global Rare Diseases Patient Registry (GRDPR) and data repository standard. Inclusion criteria are clinical diagnosis of OPMD and positive genetic testing. Patients who meet inclusion criteria will be examined using a series of multi-disciplinary investigations and questionnaires including periodic follow-up examinations. Specific attention is given to comprehensive neurological, swallowing, and ophthalmological evaluations.DiscussionThe establishment of this national registry will enhance our understanding of the natural history of OPMD, establish quality care benchmarks, and develop treatment strategies in addressing the multi-system pathophysiology of the disease and associated comorbidities. Our registry provides a foundation for the use of new cutting-edge treatments as they become available.

The blood count as a compass to navigate in the ever-changing landscape of the carrier state of hemoglobinopathies: a single-center Italian experience.

Approximately 7% of the worldwide population exhibits variations in the globin genes. The recent migration of populations from countries where hemoglobin disorders are endemic has resulted in important epidemiological changes with the diffusion of newly discovered or poorly characterized genetic variants and new combinations and very heterogeneous clinical phenotypes. The aim of our study is to assess the parameters that are more significant in predicting a positive genetic testing outcome for hemoglobinopathies in a pediatric population of patients presenting with anemia or microcythemia, without a definite diagnosis. This study included patients evaluated in our hematological outpatient clinic for anemia and/or microcythemia despite normal ferritin levels. A screening of pathological hemoglobins using high-performance liquid chromatography (HPLC) was performed for the entire population of the study. Subsequently, patients with hemoglobin (Hb) S trait and patients with an HPLC profile compatible with beta thalassemia trait were excluded from the study. Genetic screening tests for hemoglobinopathies were performed on the remaining patients, which involved measuring the red blood cell (RBC) counts, red blood cells distribution width (RDW), reticulocyte count, and mean corpuscular volume of reticulocytes (MCVr). This study evaluated a total of 65 patients, consisting of nine patients with negative genetic analysis results and 56 patients with positive genetic analysis results. The Hb and RDW values in these two groups did not demonstrate statistical significance. On the other hand, there were statistically significant differences observed in the mean corpuscular volume (MCV), RBC count, reticulocyte count, and MCVr between the two groups. Furthermore, in the group of patients with positive genetic test results, specific genetic findings associated with different HPLC results were observed. In particular, 13 patients with positive genetic test results had normal HPLC findings. This study has demonstrated that HPLC, while serving as a valuable first-level test, has some limitations. Specifically, it has been observed that some patients may exhibit a negative HPLC result despite a positive genetic analysis. In addition to the presence of low levels of Hb and HPLC alterations, other parameters could potentially indicate the underlying mutations in the globin genes. Therefore, we propose that the complete blood cell count be utilized as a widely available parameter for conducting targeted genetic analyses to avoid the risk of overlooking rare hemoglobinopathies.

Genetic screening for hereditary transthyretin amyloidosis with polyneuropathy in western Sicily: Two years of experience in a neurological clinic.

Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) is caused by mutations in the TTR gene, leading to misfolded monomers that aggregate generating amyloid fibrils. A prospective systematic genetic screening for ATTRv-PN was proposed in patients presenting with a sensory-motor idiopathic polyneuropathy and two or more "red flags" among the following: family history of polyneuropathy or cardiopathy, bilateral carpal tunnel syndrome, cardiac insufficiency, renal amyloidosis, lumbar tract stenosis, autonomic dysfunction, idiopathic gastrointestinal disease, amyloid deposits on biopsy, and vitreous opacities. The detection rate was calculated, and nonparametric analyses were carried out to underline differences among screened positive versus negative patients. In the first step, 145 suspected patients underwent genetic testing, revealing a diagnosis of ATTRv-PN in 14 patients (10%). Then, cascade screening allowed early recognition of 33 additional individuals (seven symptomatic ATTRv-PN patients and 26 presymptomatic carriers) among 84 first-degree relatives. Patients with a positive genetic test presented a higher frequency of unexplained weight loss, gastrointestinal symptoms, and family history of cardiopathy. A systematic screening for ATTRv-PN yielded an increased recognition of the disease in our neurological clinic. Unexplained weight loss associated with axonal polyneuropathy had the highest predictive value in the guidance of clinical suspicion. A focused approach for the screening of ATTRv-PN could lead to an earlier diagnosis and identification of asymptomatic carriers, who will be promptly treated after a strict follow-up at the clinical onset.

Proteomic and phosphoproteomic analyses of myectomy tissue reveals difference between sarcomeric and genotype-negative hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetically heterogenous condition with about half of cases remaining genetically elusive or non-genetic in origin. HCM patients with a positive genetic test (HCMSarc) present earlier and with more severe disease than those with a negative genetic test (HCMNeg). We hypothesized these differences may be due to and/or reflect proteomic and phosphoproteomic differences between the two groups. TMT-labeled mass spectrometry was performed on 15 HCMSarc, 8 HCMNeg, and 7 control samples. There were 243 proteins differentially expressed and 257 proteins differentially phosphorylated between HCMSarc and HCMNeg. About 90% of pathways altered between genotypes were in disease-related pathways and HCMSarc showed enhanced proteomic and phosphoproteomic alterations in these pathways. Thus, we show HCMSarc has enhanced proteomic and phosphoproteomic dysregulation observed which may contribute to the more severe disease phenotype.

Laparoscopic prophylactic total gastrectomy with limited lymphadenectomy for CDH1 gene carriers.

CDH1 gene mutations are the leading etiology of hereditary diffuse gastric cancer with cumulative lifetime risk ranging up to 83%. Prophylactic total gastrectomy (PTG) is, therefore, recommended for CDH1 carriers. A laparoscopic approach may reduce operative risk versus an open operation, thus leading more patients with CDH1 mutations to pursue PTG prior to cancer development. However, more experience and oncologic outcome data are needed for a laparoscopic approach and indicated lymphadenectomy. A retrospective descriptive cohort study of adult patients with CDH1 mutations who underwent laparoscopic PTG with D1 lymphadenectomy between 2012 and 2022 was conducted at a single institution. All patients had preoperative EGD screening, and those with visible tumor lesions on surveillance EGD were excluded and not considered prophylactic. Demographics, family history, pathology, and operative course were obtained. Outcomes included complications, readmission, and postoperative weight change. Among 23 patients, median age was 48years (IQR 37, 53) and 15 (65%) were female. Family history for gastric and/or lobular breast cancer was present in 22 (96%) patients. The median [IQR] time from positive genetic testing to PTG was 347days [140, 625]. Pathologic evaluation showed five (22%) patients with foci of gastric cancer on pre-operative EGD biopsies, 10 (44%) in resected stomach specimens. All lymph nodes were negative. To address early postoperative complications, EJ anastomotic technique changed from EEA to GIA over the course of the study and feeding jejunostomy was no longer placed during PTG with minimal change in postoperative weight loss. This is the largest series, spanning 10years at a single institution, dedicated solely to a laparoscopic approach for risk-reducing PTG. A laparoscopic approach with limited lymphadenectomy resulted in acceptable surgical and oncologic outcomes. Despite no visible cancer, over half of our patients had foci of early gastric cancer. Therefore, CDH1 carriers should consider laparoscopic PTG.

Hereditary Renal Cell Carcinoma: Is Age an Independent Criterion for Genetic Testing? A Large Cohort from a Latin America Referral Center.

Although age younger than 46 years has been an independent criterion for genetic testing in hereditary renal cell carcinoma (hRCC), there is a lack of evidence in the literature. This study aims to analyze whether a 46-year-old cut-off should be considered an independent genetic testing criterion and to elucidate risk factors predicting a positive genetic test. Observational study from January 2010 to December 2021. All patients under 46 years with a non-metastatic kidney mass and surgical indication were included. We assume patients who relapse in the first 5 years of follow-up could have a positive genetic test. As risk factors for relapse, ergo positive genetic test, we consider those patients who presented multifocal, bilateral, or previous renal tumor. Of 2,232 nephrectomies for kidney cancer, 301 patients met the inclusion criteria. The median follow-up was 60 months (IQR 29-101). The estimated five-year RFS was 94.4% (95% CI 91.3-97.5). Tumor size, previous renal tumor, multifocality, bilaterality, and pT3 or pT4 stage were independent recurrence risk factors. Genetic testing was performed on 24 patients. 10 patients had pathogenic variants in the test, 8 of which recurred during their life. 46-year-old cut-off has shown low performance in genetic testing. Therefore, we recommend that it be considered only if other hRCC risk criteria exist. Multifocality, bilaterality, and previous renal tumor could predict a positive genetic test.

Screening, Genetic Variants, and Bipolar Disorders: Can Useful Hypotheses Arise from the Sum of Partial Failures?

Bipolar disorder (BD) is a relevant public health issue, therefore accurate screening tools could be useful. The objective of this study is to verify the accuracy of the Mood Disorder Questionnaire (MDQ) and genetic risk as screeners, and their comparison in terms of reliability. Older adults (N = 61, ≥60 years) received a clinical psychiatric evaluation, the MDQ, and were evaluated according to the presence of the genetic variant RS1006737 of CACNA1C. MDQ+ versus the diagnosis of BD as a gold standard shows a sensitivity of 0.286 (Cl 95% 0.14-0.39); a specificity of 0.925 (Cl 95% 0.85-0.08); a predictive positive value (PPV) of 0.667 (Cl 95% 0.33-0.91); and a predictive negative value (PNV) of 0.702 (Cl 95% 0.65-0.75). The positivity for the variant RS1006737 of the CACNA1C against the diagnosis of BD as a gold standard shows a sensitivity of 0.750 (Cl 95% 0.55-0.90); a specificity of 0.375 (Cl 95% 0.28-0.45); a PPV of 0.375 (Cl 95% 0.28-0.45); and a PNV of 0.750 (Cl 95% 0.55-0.90). The reliability between the MDQ+ and positivity for the variant RS1006737 of the CACNA1C was very low (K = -0.048, Cl 95% -0.20-0.09). The study found that both the genetic and the paper and pencil test were quite accurate, but were not reliable in case finding. In fact, despite some validity, albeit specular (in the case of a positive genetic test, the probability of having the disorder is very high, whereas in the case of a negative score on the paper and pencil test, the probability of not having the disorder is very high), the unreliability of the two tests (i.e., they certainly do not measure the same underlying dimension) opens the door to the need for an interpretation and the possibility of a synergistic use for screening. From a heuristic perspective, which obviously requires all of the necessary verifications, this study seems to suggest the hypothesis that a condition of hyperactivation common to disorders and stress conditions, and identified by a positive score on the MDQ (which is common to BD, post-traumatic stress disorder (PTSD), and anxiety disorders and whose genetic basis has not yet been clarified) can trigger BD in people with a predisposition to hyperactivity (i.e., in people with the condition identified by the analyzed genetic variant).

De novo biopsy-negative Alport Syndrome: a novel mutation variant

Alport syndrome (AS) is an inherited disease caused by a mutation in type IV collagen genes, including the COL4A3 COL4A4 and COL4A5 genes. X-linked Alport syndrome associated with a mutation in COL4A5 gene is the most commonly observed type of AS. The clinical symptoms of AS include renal, hearing and vision impairments. The diagnosis is based on the manifestation of these symptoms and either specific kidney biopsy lesions or positive genetic tests. We present a case of a de novo biopsy negative Alport syndrome. The patient’s diagnosis was delayed because the biopsy did not show specific findings for AS. Genetic tests (Next-Gen Sequencing, NGS) made it possible to establish the final correct diagnosis. A c.2441G&gt;A variant of COL4A5 gene detected in probant has not been described in the literature yet. In the past years a significance of NGS in AS diagnosis has increased. The new pathogenic variants are still being reported including de novo mutations having an incidence rate of around 12%. Early diagnosis is crucial for the effective treatment of patients with AS.

The spectrum of hereditary neuromuscular disorders in the Pakistani population.

Hereditary neuromuscular disorders (NMDs) are a broad group of clinically heterogeneous disorders with varying inheritance patterns, that are associated with over 500 implicated genes. In the context of a highly consanguineous Pakistani population, we expect that autosomal recessive NMDs may have a higher prevalence compared with patients of European descent. This is the first study to offer a detailed description of the spectrum of genes causing hereditary NMDs in the Pakistani population using NGS testing. To study the clinical and genetic profiles of patients presenting for evaluation of a hereditary neuromuscular disorder. This is a retrospective chart review of patients seen in the Neuromuscular Disorders Clinic and referred to the Genetics Clinic with a suspected hereditary neuromuscular disorder, between 2016 and 2020 at the Aga Khan University Hospital, Karachi and Mukhtiar A. Sheikh Hospital, Multan, Pakistan. The genetic testing for these patients included NGS-based single gene sequencing, NGS-based multi-gene panel and whole exome sequencing. In a total of 112 patients studied, 35 (31.3%) were female. The mean age of onset in all patients was 14.6 years (SD ±12.1 years), with the average age at presentation to the clinic of 22.4 years (SD ±14.10 years). Forty-seven (41.9%) patients had a positive genetic test result, 53 (47.3%) had one or more variants of uncertain significance (VUS), and 12 (10.7%) had a negative result. Upon further genotype-phenotype correlation and family segregation analysis, the diagnostic yield improved, with 59 (52.7%) patients reaching a diagnosis of a hereditary NMD. We also report probable founder variants in COL6A2, FKTN, GNE, and SGCB, previously reported in populations that have possible shared ancestry with the Pakistani population. Our findings reemphasizes that the rate of VUSs can be reduced by clinical correlation and family segregation studies.