Methyl-CpG-Binding protein 2 duplication syndrome in a Chinese patient: A case report and review of the literature

Abstract

BACKGROUND

Chromosomal Xq28 region duplication encompassing methyl-CpG-binding protein 2 (MECP2) results in an identifiable phenotype and global developmental delay known as MECP2 duplication syndrome (MDS). This syndrome has a wide range of clinical manifestations, including abnormalities in appearance, neurodevelopment, and gastrointestinal motility; recurrent infections; and spasticity. Here, we report a case of confirmed MDS at our institution.

CASE SUMMARY

A 12-year-old Chinese boy presented with intellectual disability (poor intellectual [reasoning, judgment, abstract thinking, and learning] and adaptive [lack of communication and absent social skills, apraxia, and ataxia] functioning) and dysmorphism. He had no history of recurrent infections, seizures, or bowel dysfunction, which is different from that in reported cases. Microarray comparative genomic hybridization confirmed MECP2 duplication in the patient and his mother who is a carrier. The duplication size was the same in the patient and his mother. No prophylactic antibiotic or anti-seizure therapy was offered to the patient or his mother before or after the consultation.

CONCLUSION

MDS is rare and has various clinical presentations. Clinical suspicion is critical in patients presenting with developmental delays.

Keywords: Methyl-CpG-binding protein 2; Neurodevelopmental Delay; Xq28 duplication; Array comparative genomic hybridization; Case report

Core Tip: Methyl-CpG-binding protein 2 (MECP2) duplication syndrome is a rare X-linked neurodevelopmental disorder. There is a paucity of data describing typical MECP2 syndrome cases in the literature. We describe the case of a Chinese boy with no history of seizure, recurrent infections, or bowel impairment from birth, who inherited duplication of the Xq28 region, including MECP2, from his mother who is a carrier, and discussed the clinical and genetic characteristics of this family. A lack of microduplication of genes in the Xq28 region may explain the absence of typical symptoms, which adds to previous reports of a rare genetic mutation in China.