The role of factor V Leiden and prothrombin G20210A mutations in sudden sensorineural hearing loss.

Objectives: To investigate the incidence of factor V Leiden and prothrombin G20210A in sudden sensorineural hearing loss patients.

Study Design: The patient group for this study was selected prospectively in the case of 28 patients and retrospectively in the case of another 28.

Setting: Tertiary referral center.

Patients: Fifty-six patients (29 female, 27 male) with sudden sensorineural hearing loss (SSHL) and 95 control subjects (48 female, 47 male) were enrolled in this study. The age of the control subjects were between 26 and 76 (38 +/- 16.7), and that of the patients were between 10 and 87 (42.6 +/- 18.2).

Intervention: The factor V Leiden and prothrombin G20210A mutations were detected by rapid polymerase chain reaction amplification of genomic DNA extracted from the SSHL patients' peripheral blood cells.

Main Outcome Measure: Thrombotic microangiopathic disorders are characterized by widespread microvascular thrombosis leading to end-organ injury. The mutations of factor V Leiden and prothrombin gene are known as genetic risk factors for thrombotic microangiopathy in normal patients. SSHL may occur with occlusion of the cochlear blood supply by microthromboangiopathy.

Results: Factor V Leiden mutation was found to be higher in SSHL patients when compared with control subjects (16.1% vs 5.3%). The difference between the two groups was found to be statistically significant (p = 0.02). However, statistical significance was not found between the groups in regard to prothrombin G20210A mutation. Factor V Leiden and prothrombin gene mutations were heterozygous in all of the subjects.

Conclusion: A significant association between factor V Leiden mutation and idiopathic SSHL could be shown in this study. There was no correlation, however, between the occurrence of idiopathic SSHL and prothrombin mutation.