Rates and Classification of Variants of Uncertain Significance in Hereditary Disease Genetic Testing.

Importance: Variants of uncertain significance (VUSs) are rampant in clinical genetic testing, frustrating clinicians, patients, and laboratories because the uncertainty hinders diagnoses and clinical management. A comprehensive assessment of VUSs across many disease genes is needed to guide efforts to reduce uncertainty.

Objective: To describe the sources, gene distribution, and population-level attributes of VUSs and to evaluate the impact of the different types of evidence used to reclassify them.

The natural history of Pelizaeus-Merzbacher disease caused by PLP1 duplication: A multiyear case series.

This study aimed to characterize the clinical features, developmental milestones, and the natural history of Pelizaeus-Merzbacher disease (PMD) associated with gene duplications. The study examined 16 PMD Patients ranging in age from 7 to 48 years, who had a documented gene duplication. The study examined and analyzed the medical and developmental histories of the subjects utilizing a combination of resources that included medical history questionnaires, medical record reviews, and a 31-point functional disability scale that had been previously validated.

Physician-directed genetic screening to evaluate personal risk for medically actionable disorders: a large multi-center cohort study.

Background: The use of proactive genetic screening for disease prevention and early detection is not yet widespread. Professional practice guidelines from the American College of Medical Genetics and Genomics (ACMG) have encouraged reporting pathogenic variants that confer personal risk for actionable monogenic hereditary disorders, but only as secondary findings from exome or genome sequencing. The Centers for Disease Control and Prevention (CDC) recognizes the potential public health impact of three Tier 1 actionable disorders.

Elucidating clinical phenotypic variability associated with the polyT tract and TG repeats in CFTR.

Biallelic pathogenic variants in CFTR manifest as cystic fibrosis (CF) or other CFTR-related disorders (CFTR-RDs). The 5T allele, causing alternative splicing and reduced protein activity, is modulated by the adjacent TG repeat element, though previous data have been limited to small, selective cohorts. Here, the risk and spectrum of phenotypes associated with the CFTR TG-T5 haplotype variants (TG11T5, TG12T5, and TG13T5) in the absence of the p.

Limited-Variant Screening vs Comprehensive Genetic Testing for Familial Hypercholesterolemia Diagnosis.

Importance: Familial hypercholesterolemia (FH) is the most common inherited cardiovascular disease and carries significant morbidity and mortality risks. Genetic testing can identify affected individuals, but some array-based assays screen only a small subset of known pathogenic variants.

Objective: To identify the number of clinically significant variants associated with FH that would be missed by an array-based, limited-variant screen when compared with next-generation sequencing (NGS)-based comprehensive testing.

Clinical Genetic Testing for the Cardiomyopathies and Arrhythmias: A Systematic Framework for Establishing Clinical Validity and Addressing Genotypic and Phenotypic Heterogeneity.

Advances in DNA sequencing have made large, diagnostic gene panels affordable and efficient. Broad adoption of such panels has begun to deliver on the promises of personalized medicine, but has also brought new challenges such as the presence of unexpected results, or results of uncertain clinical significance. Genetic analysis of inherited cardiac conditions is particularly challenging due to the extensive genetic heterogeneity underlying cardiac phenotypes, and the overlapping, variable, and incompletely penetrant nature of their clinical presentations.