A novel nonsense mutation of ZEB2 gene in a Chinese patient with Mowat-Wilson syndrome.

BACKGROUND Mowat-Wilson syndrome (MWS) is a rare genetic disorder characterized by intellectual disability, distinctive facial features, and multiple anomalies caused by haploinsufficiency of the ZEB2 gene. We investigated the genetic causes of MWS in a 14-year-old girl who had characteristic features of MWS. METHODS Clinical data and peripheral blood DNA samples were collected from the proband. Following extraction of genomic DNA, whole-exome sequencing was conducted to detect genetic variants. Bioinformatics analysis was carried out to predict the function of the mutant gene. RESULTS Mutation analysis of the proband identified a novel nonsense mutation (c.250G > T, p.E84*) within exon 3 of the ZEB2 gene. This novel alteration resulted in a termination codon at amino acid position 84, which was predicted to encode a truncated protein. This variant was not present in unrelated healthy control samples that were obtained from the exome sequence databases ExAc browser (http://exac.broadinstitute.org/) and gnomAD browser (http://gnomad.broadinstitute.org/). It is a novel variant that was determined to be a deleterious mutation according to the variant interpretation guidelines of the ACMG. The results of our study suggest that the p.E84* mutation in the ZEB2 gene was probably the pathogenic mutation that caused MWS in the proband. CONCLUSIONS This study reports the novel mutation in the proband will provide a basic foundation for further investigations to elucidate the ZEB2-related mechanisms of MWS.