Detection of genomic copy number variations in patients with unexplained mental retardation/developmental delay by low coverage whole-genome sequencing.

Author: Hui SONG ¹ ; Panlai SHI ; Yanhua XIAO ; Yaqin HOU ; Duo CHEN ; Xiangdong KONG
Author Information

1. Prenatal Diagnosis Center, General Hospital of Wanbei Coal and Power Group, Suzhou, Anhui 234000, China. kongxd@263.net.
Publication Type:Journal Article
From: Chinese Journal of Medical Genetics 2020;37(9):953-957
CountryChina
Language:Chinese
Abstract: OBJECTIVE:To detect genomic copy number variations (CNVs) among 145 children with unexplained mental retardation/developmental delay (MR/DD) by using low-depth whole-genome copy number variation sequencing (CNV-seq).
METHODS:Peripheral blood samples were collected from the patients and subjected to DNA extraction and CNV-seq. The results were analyzed by a combination of bioinformatic tools.
RESULTS:Forty-nine patients were found to carry a total of 67 CNVs with an average size of 5.27 Mb. Among these, 22 patients were assessed to carry MR/DD-related CNVs involving 21 syndromes. This gave a diagnostic rate of 15.17%(22/145) for CNVs associated with unexplained MR/DD. The corresponding regions of the 22 MR/DD-related CNVs in the human genome covered 174 MR/DD-related pathogenic genes, which have mapped to 18 sections on 10 chromosomes.
CONCLUSION:Genomic CNVs-related microdeletions/duplications account for a significant proportion of unexplained MR/DD, for which CNV-seq can provide an accurate diagnosis.