@article {915, title = {Low-level parental somatic mosaic SNVs in exomes from a large cohort of trios with diverse suspected Mendelian conditions.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 11}, pages = {1768-1776}, abstract = {

PURPOSE: The goal of this study was to assess the scale of low-level parental mosaicism in exome sequencing (ES) databases.

METHODS: We analyzed approximately 2000 family trio ES data sets from the Baylor-Hopkins Center for Mendelian Genomics (BHCMG) and Baylor Genetics (BG). Among apparent de novo single-nucleotide variants identified in the affected probands, we selected rare unique variants with variant allele fraction (VAF) between 30\% and 70\% in the probands and lower than 10\% in one of the parents.

RESULTS: Of 102 candidate mosaic variants validated using amplicon-based next-generation sequencing, droplet digital polymerase chain reaction, or blocker displacement amplification, 27 (26.4\%) were confirmed to be low- (VAF between 1\% and 10\%) or very low (VAF <1\%) level mosaic. Detection precision in parental samples with two or more alternate reads was 63.6\% (BHCMG) and 43.6\% (BG). In nine investigated individuals, we observed variability of mosaic ratios among blood, saliva, fibroblast, buccal, hair, and urine samples.

CONCLUSION: Our computational pipeline enables robust discrimination between true and false positive candidate mosaic variants and efficient detection of low-level mosaicism in ES samples. We confirm that the presence of two or more alternate reads in the parental sample is a reliable predictor of low-level parental somatic mosaicism.

}, keywords = {Exome, High-Throughput Nucleotide Sequencing, Humans, Mosaicism, Parents, Whole Exome Sequencing}, issn = {1530-0366}, doi = {10.1038/s41436-020-0897-z}, author = {Gambin, Tomasz and Liu, Qian and Karolak, Justyna A and Grochowski, Christopher M and Xie, Nina G and Wu, Lucia R and Yan, Yan Helen and Cao, Ye and Coban Akdemir, Zeynep H and Wilson, Theresa A and Jhangiani, Shalini N and Chen, Ed and Eng, Christine M and Muzny, Donna and Posey, Jennifer E and Yang, Yaping and Zhang, David Y and Shaw, Chad and Liu, Pengfei and Lupski, James R and Stankiewicz, Pawe{\l}} }