Clinical diagnosis and mutation analysis of a Chinese boy with Phelan-McDermid syndrome

Abstract

Objective To explore the clinical features and genetic diagnosis analysis of a Chinese boy with unexplained overgrowth and developmental delay. Methods The clinical symptoms of the boy were described, and performed routine G-banding was performed to analyze the karyotype of the patient, and multiplex ligation-dependent probe amplification(MLPA) was used to detect the copy number variation(CNVs) in the 22q13 region, and array-comparative genomic hybridization(array CGH) was used to detect all chromosome abnormally, then fluorescence in situ hybridization(FISH) confirmed the result. Results 1.The boy was 1.5 years old and complained about accelerated growth, global developmental delay, severely delayed speech ability and peculiar facial features.2.Routine karyotype analysis showed a karyotype of 46, XY.MLPA found terminal deletion with breakpoints within the SHANK3 gene and ACR gene, RABL2B gene, and array CGH finely mapped the deletion on 22q13, furthermore FISH confirmed the micro deletion. Conclusions Combining the clinical manifestations and effective examination of 22q13 deletion, the boy got a reliable diagnosis of Phelan-McDermid syndrome; as array CGH can be useful to screen CNVs of all chromosome, so MLPA should be applied to some special CNVs. Key words: Phelan-McDermid syndrome; Overgrowth; Developmental delay; Multiplex ligation-dependent probe amplification; Array-comparative genomic hybridization