Analysis of IQSEC2 gene variant in a child with X-linked mental retardation

Abstract

To analyze the clinical phenotype and genetic variants of a child with X-linked mental retardation caused by IQSEC2 gene mutation, and provide reference for the diagnosis of the disease. The child was subjected to next generation sequencing (NGS), and the diagnosis was made by taking consideration of her clinical characteristics. The child has presented with global developmental delay, particularly in fine motor skill and language development, in addition with intellectual disability. Genetic testing revealed that she has harbored a heterozygous c.1861dup variant of the IQSEC2 gene, which was not detected in either parent. The de novo c.186ldup variant of the IQSEC2 gene probably underlay the X-linked mental retardation in this child. Above finding has, expanded the spectrum of IQSEC2 gene mutations and provide a basis for the diagnosis of similar cases.