Objective: To make a further exploration of the mutation frequence of Chinese genetic deafness and make clear if the genetic deafness genealogy that we collected recently was resulted from the mutation of the deafness genes which had been cloned.
Method: We made regular otologic examination, hearing test and physical examination among the members of this genealogy, and also inspected the mutation of seven autosomal domiant deafness genes, HDIAI,GJB2, GJB3, DFNA5, a-tectorin(resulting in two types of genetic deafness, DFNA8 and DFNA12), MYO7A,POU4F3, with PCR-Sequencing method in this genealogy.
Result: 1. The analysis of hereditary mode: There were forty-seven persons collected in five generations of this genealogy, and eighteen persons of them were deafness. It accorded with autosomal dominant inheritance from the pedigree. 2. The clinic feature: All patients with deafness were postlingual deafness. Their hearing decreased onset between sixteen to thirty years old, and the deafness was binaural symmetrical, progressive sensorineural and without other systems abnormity. 3. Analysis of mutation detection: We found two nucleotides changes in CX26 genes, A341G and GC257-258CG, and one changed nucleotide in POU4F3 gene,T90C. But we didn't think the changed nucleotides caused deafness after we analysed them. No mutation was found in other five genes.
Conclusion: The possibility that the deafness of this genealogy was resulted from the cloned gene is relatively small. Now, We are scanning the whole gene groups and making linkage analysis on this pedigree, it is most probably to orientate a new deafness gene position.