Gene mutation analysis in a Chinese pedigree with autosomal dominant Waardenburg syndrome / 中华皮肤科杂志

ABSTRACT

Objective:To report a Chinese pedigree with autosomal dominant Waardenburg syndrome, and to identify causative gene mutations.Methods:Clinical data and peripheral blood samples were collected from the proband and her parents. Genomic DNA was extracted, gene mutations were detected through a next-generation skin-targeted sequencing panel, and Sanger sequencing was performed to verify causative mutations.Results:The proband clinically presented with irregular white patches on the abdomen and lower limbs, moderate to severe sensorineural deafness in the right ear, and iris heterochromia in both eyes. The proband′s mother presented with iris heterochromia in both eyes, epicanthus, early canities and thick eyebrows. In the family, both the proband and her mother were diagnosed with Waardenburg syndrome. A causative frameshift mutation c.976-977delinsT (p.Thr327Profs*54) was identified in both the proband and her mother, which caused the AG to TT base substitution at positions 976 - 977 in the coding region of exon 7 of the PAX3 gene, resulted in a frameshift from the amino acid position 327 to 54 in the PAX3 protein (threonine was substituted by proline at amino acid position 327). The proband′s father showed a normal phenotype, and his genetic test results were negative.Conclusion:The novel frameshift mutation c.976-977delinsT (p.Thr327Profs*54) in the PAX3 gene may contribute to the clinical phenotype of the patients with Waardenburg syndrome in the family.