[Analysis of ASXL3 gene variant in a child with Bainbridge-Ropers syndrome]

To explore the genetic basis for a child affected with Bainbridge-Ropers syndrome.

Genomic DNA was extracted from peripheral venous blood samples from the patient and his parents. Whole exome sequencing (WES) was carried out to detect genetic variant of the proband. Candidate variant was verified by Sanger sequencing.

The 3-year-old boy presented with psychomotor retardation, linguistic difficulties, mental retardation and peculiar craniofacial phenotype. A de novo heterozygous nonsense variant of the ASXL3 gene, c.3106C>T, was identified by WES in the proband, and the same mutation was not found among his parents. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.3106C>T variant was predicted to be pathogenic (PVS1+PS2+PP4).

The heterozygous variant c.3106C>T of the ASXL3 gene probably underlies the Bainbridge-Ropers syndrome in the patient. Above result has enabled the clinical diagnosis and genetic counseling for the family.