AI Article Synopsis

  • Disorders of somatic mosaicism (DoSM) involve various conditions caused by genetic variants that impact cell survival and growth, yet few labs focus on diagnosing these compared to cancer.
  • A high-sensitivity next-generation sequencing test adapted for DoSM has been used to analyze 343 individuals, revealing a 58% rate of pathogenic or likely pathogenic findings.
  • Key factors improving diagnostic outcomes included deep sequencing, a comprehensive gene panel, and testing different tissue types, with buccal swabs proving particularly effective for certain head or brain conditions.

Article Abstract

Disorders of somatic mosaicism (DoSM) are a diverse group of syndromic and non-syndromic conditions caused by mosaic variants in genes that regulate cell survival and proliferation. Despite overlap in gene space and technical requirements, few clinical labs specialize in DoSM compared to oncology. We adapted a high-sensitivity next-generation sequencing cancer assay for DoSM in 2014. Some 343 individuals have been tested over the past 5 years, 58% of which had pathogenic and likely pathogenic (P/LP) findings, for a total of 206 P/LP variants in 22 genes. Parameters associated with the high diagnostic yield were: (1) deep sequencing (∼2,000× coverage), (2) a broad gene set, and (3) testing affected tissues. Fresh and formalin-fixed paraffin embedded tissues performed equivalently for identification of P/LP variants (62% and 71% of individuals, respectively). Comparing cultured fibroblasts to skin biopsies suggested that culturing might boost the allelic fraction of variants that confer a growth advantage, specifically gain-of-function variants in PIK3CA. Buccal swabs showed high diagnostic sensitivity in case subjects where disease phenotypes manifested in the head or brain. Peripheral blood was useful as an unaffected comparator tissue to determine somatic versus constitutional origin but had poor diagnostic sensitivity. Descriptions of all tested individuals, specimens, and P/LP variants included in this cohort are available to further the study of the DoSM population.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6817554PMC
http://dx.doi.org/10.1016/j.ajhg.2019.09.002DOI Listing

Publication Analysis

Top Keywords

p/lp variants
12
next-generation sequencing
8
disorders somatic
8
somatic mosaicism
8
variants genes
8
high diagnostic
8
diagnostic sensitivity
8
variants
6
diagnostic
4
diagnostic utility
4

Similar Publications

Biomarkers.

Alzheimers Dement

December 2024

Xiangya Hospital, Central South University, Changsha, Hunan, China.

Background: Frontotemporal dementia (FTD) exhibits clinical phenotypic and genetic heterogeneity. However, reports on the clinical phenotypic characteristics and the frequency of genetic mutations in large-sample Chinese populations with FTD are lacking. Furthermore, the FTD diagnostic performance of plasma neurodegenerative biomarkers remains unclear.

View Article and Find Full Text PDF

Purpose: Breast cancer (BC) is the commonest cancer in South African women. A proportion are associated with a pathogenic or likely pathogenic (P/LP) variant in a BC susceptibility gene. Clinical guidelines for genetic testing are used to optimise variant detection while containing costs.

View Article and Find Full Text PDF

Introduction: Due to the recent advent of gene-targeted retinal therapies, the clinical value of high-yield genetic testing for inherited retinal dystrophies (IRDs) has increased considerably. However, diagnostic yield is limited by the reported patient populations in allele frequency databases. This study aimed to determine the effect of race and ethnicity on diagnostic yield in IRDs.

View Article and Find Full Text PDF

Objectives: At present, most genetic tests or carrier screening are performed with blood samples, and the known carrier rate of disease-causing variants is also derived from blood. For semen donors, what is really passed on to offspring is the pathogenic variant in their sperm. This study aimed to determine whether pathogenic variants identified in the sperm of young semen donors are also present in their blood, and whether matching results for blood are consistent with results for sperm.

View Article and Find Full Text PDF

Routine Prenatal cfDNA Screening for Autosomal Dominant Single-Gene Conditions.

Clin Chem

January 2025

Division of Maternal-Fetal-Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.

Background: Genetic screening has advanced from prenatal cell-free DNA (cfDNA) screening for aneuploidies (cfDNA-ANP) to single-gene disorders (cfDNA-SGD). Clinical validation studies have been promising in pregnancies with anomalies but are limited in the general population.

Methods: Chart review and laboratory data identified pregnancies with cfDNA-SGD screening for 25 autosomal dominant conditions at our academic center.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!