Clinical and genetic analysis of ten Chinese pedigrees affected with 7q11.23 duplication syndrome

Abstract

To analyze the clinical and genetic characteristics of ten Chinese pedigrees affected with 7q11.23 duplication syndrome. From December 2017 to January 2022, ten pedigrees diagnosed with 7q11.23 duplication syndrome at the First Affiliated Hospital of Zhengzhou University were enrolled as the study subjects. Clinical data of all subjects were collected, and some had subjected to copy number variation sequencing or single nucleotide polymorphism array to analyze the pattern of inheritance. The probands had included six fetuses and four adolescents. Four of the six prenatal cases showed abnormal ultrasound indicators, including three with soft indicators and one with abnormal fetal structural development. The clinical phenotype of the four adolescent cases had included mental retardation, delayed language development, and attention deficit hyperactivity disorder. The size of the copy number variations had ranged from 1.31 to 1.42 Mb, involving the classic region of 7q11.23 duplication syndrome. Of these, five cases had undergone parental origin testing, three cases were de novo, and two were hereditary. Individuals with 7q11.23 duplication syndrome may show substantial clinical phenotypic heterogeneity, hence the affected families should be provided with pre-pregnancy consultation and reproductive guidance.