Genotype and phenotype analysis of a family with Waardenburg syndrome type Icaused by a novel mutation in PAX3 gene

Objective:To identify gene mutation and analysis the association between clinical characterizes and the mutations in a family of Waardenburg syndrome （WS） type I in Yunnan, China. Methods:With informed consent, the proband with WS phenotype and his family members were given medical history collection, physical examination and audiological evaluation. Peripheral blood was obtained, genomic DNA was extracted, and deafness related genes were detected by high-throughput sequencing. Sanger sequencing was used to verify the mutation sites of proband and his family members. Results:C. 602C>G mutation in exon 5 of PAX3 gene was identified, which is nonsense mutation and may cause a truncated protein. The mutation cause 201 amino acid of the protein changed from serine to stop codon. According to the American College of Medical Genetics and Genomics （ACMG）, it is considered as Pathogenicity（PVS1+PM2+PP3）. This mutation has not been included in the database also not been reported in the literature. Conclusion:Combined with the results of clinical diagnosis and gene diagnosis, this mutation was considered as the cause of the disease. This study enriched mutation spectrum of PAX3 gene.