DFNA20/26 hearing impairment:The mutation of the ACTG1 gene and its phenotypic analysis
Objective To provide an etiological diagnosis for two Chinese family with non-syndromic progressive hearing loss and discuss clinical audiological characteristics of the ACTG1 mutations that caused DFNA20/26 hearing impairment.Methods Information of family history was collected and genealogy was drawn.A comprehensive physical examination,audiological and radiological tests were performed in affected individuals.Peripheral blood from all subjects was obtained for DNA extraction,then whole-exome sequencing was applied to screen candidate variants.The literature was retrieved to summarize the audiological characteristics of DFNA20/26 hearing impairment.Results All patients presented with post-lingual progressive non-syndromic sensorineural hearing loss.Genetic testing identified two ACTG1 variants in family 1 and family 2:c.721G＞A and c.773C＞G,respectively.ACTG1 mutations cause DFNA20/26 hearing impairment beginning in the one to two decades which was initially predominated at high frequencies and later deteriorated to severe to profound HL at full frequencies with age(-1 dB/year).Conclusions The etiology of hearing loss in family 1 was attributed to c.721G＞A mutation.The findings of c.773C＞G mutation supplement the mutation spectrum of the ACTG1 gene,and the elucidation of phenotypic features is beneficial to enhance clinicians'knowledge of DFNA20/26 hearing impairment and facilitate genetic counseling for the family.
NETL
NSTL
万方数据
