[Phenotypic and genotypic analysis of a girl carrying a 2q22.3 microduplication encompassing the MBD5 gene]

To carry out single nucleotide polymorphism (SNP)-based chromosome microarray analysis (CMA) for a boy featuring global developmental delay.

The SNP array was conducted for the child, and real-time PCR was used to validate its result and identify the origin of pathological copy number variants.

SNP array revealed that the patient has carried a de novo 2.5 Mb duplication at 2q22.3q23.3, which encompassed ACVR2A, KIF5C, MBD5, EPC2, LYPD6, LYPD6, MMADHC and ORC4 genes. Literature review suggested that the MBD5 gene from the duplicated region may have predisposed to the global developmental delay shown by the girl.

The patient's clinical phenotype was consistent to that of 2q23 duplication, for which the MBD5 gene may play a key role. CMA has provided an important tool for the diagnosis of patients with global developmental delay.