Objective: To determine the possible gene mutation and its different sites that leads to hearing loss in a consanguineous marriage pedigree.
Method: Blood samples from a Changchun pedigree were obtained with informed consent. Their genomic DNA were extracted from peripheral blood and PCR was performed. Nine of hot spot mutations in four most common deafness pathologic gene were detected with the DNA microarray, including GJB2, GJB3, PDS and mtDNA 12S RNA gene. At the same time, the results were confirmed with the traditional methods of sequencing.
Result: GJB2 gene of 235 delC and 299-300 delAT compound heterozygous mutation was found in propositus. His father was 299-300 delAT homozygous mutation and mother was 235 delC homozygous mutation. In the relatives on the paternal side, the affected patients all were 299-300 delAT homozygous mutation and normal hearing member was 299-300 delAT heterozygous carrier. This GJB2 mutation come from grandparents of consanguineous marriage.
Conclusion: GJB2 gene mutation played on an important role in this deafness family. It is essential approach for genetic diagnosis of non - syndromic sensorineural hearing loss.