FURTHER OBSERVATIONS ON THE ROLE OF THE MHC GENES AND CERTAIN HEARINGDISORDERS

The pathogenetic mechanism of many hearing disorders have not been ful ly defined. Studies of certain hearing disorders in man have suggested a role for the major histocompatibility complex (MHC)-encoded genes i n disease pathogenesis, In a cohort of unrelated patients with Meniere 's Disease, otosclerosis and strial presbycusis as well as other types of sensorineural hearing losses, we have identified an extended MHC h aplotype common to the majority of these patients, supporting a hypoth esis that a gene(s) within the MHC domain may confer susceptibility to these hearing ailments. In addition, a preliminary study of 27 indivi duals with various hearing maladies, a striking finding is that 44% of the patients express the following extended MHC haplotype in contrast to only 7% of the general population: -C4A0-G11:15-Bf:0.4-C2a-HSP70:7 .5-TNFa5-B8-Cw7-Al. The expression of this haplotype by subsets of pat ients with hearing loss is significant in comparison to regional and i nternational controls.