Sudden hearing loss and MTHFR 677C>T/1298A>C gene polymorphisms

Purpose: Sudden hearing loss (SHL) can be caused by vascular disorders favoring impaired cochlear perfusion. A number of inherited prothrombotic risk factors have been considered in the pathogenesis of vascular impairment and the possible role of genetic alterations has recently been suggested. We aimed to investigate the relationship between SHL and MTHFR 677 and 1298 gene polymorphisms. Methods: DNA genotyping was performed on peripheral blood leukocytes in 45 SHL patients and 135 controls. Results: Wild-type MTHFR (677CC/1298AA) was significantly more frequent in the controls (P = 0.01), and gene polymorphisms (677CT, 677TT, 1298AC, 1298CC, compound 677CT/1298AC) were significantly more frequent in the patients (P = 0.005; Ptrend = 0.001). Conclusion: These data suggest that MTHFR gene polymorphisms may be considered as risk factors for SHL and participate on vascular impairment related to this disorder. Further studies, based on large series of patients, are needed to definitely assess the role of this prothrombotic factor in the etiopathogenesis of SHL.