Different clinical phenotypes and genetic characteristics of five patients with DiGeorge syndrome / 中华内分泌代谢杂志

ABSTRACT

Objective:To identify the clinical phenotypes, diagnosis, and treatment of five children with DiGeorge syndrome finally diagnosed by gene, with review of the literature.Methods:The clinical data of five children with DiGeorge syndrome admitted to our hospital were collected and sorted out. Copy number variation sequencing (CNV-seq) based on next generation sequencing (NGS) technology was used to diagnose the genetic etiology of the children. The relationship between phenotypes and genotype among these five children were emphatically compared.Results:The five children collected in this study were all younger than 6 months. The course of the disease was more than 2 months to 1 year. Most of the first symptoms were convulsions and/or repeated infection. All of them had different degrees of growth retardation, with or without special facial features, epilepsy, congenital heart disease, etc. The similar blood ionized calcium levels revealed hypocalcemia, but the frequency and severity of convulsions were different. The copy number variation of chromosome 22q11.21 was detected in all these five children, and the deletion fragment was between 2.56-2.6 Mb, which was mostly coincident with the classical deletion region of DiGeorge syndrome (chr22 19009792-21452445) recorded in Decipher database. One case was suggested to be a novel mutation, and the rest were of unknown origin.Conclusions:DiGeorge syndrome has great clinical heterogeneity. CNV-seq based on NGS technology is not only conducive to accurate genetic etiological diagnosis, but also helpful for understanding the corresponding relationship between clinical phenotype and genotype of hereditary syndrome, improving clinicians′ understanding and avoiding misdiagnosis.