The risk ratio for development of hereditary sensorineural hearing loss in consanguineous marriage offspring

Abstract

Objectives: This study aims to define the relative risk of development of hearing loss in offspring of consanguineous marriages.

Materials and methods: This is a retrospective case-control study conducted in a tertiary referral center in Jeddah, KSA. The study group included 1600 probands (848 males, 752 females), with age range 0.5-12 years (6.6 ± 3.6). The study group comprised of two equal, age and sex matched subgroups; Hearing Loss (HL) group and Normal Hearing (NH) group. The children included in the HL group should have idiopathic or non syndromic genetic sensorineural hearing loss.

Results: The HL Group comprised 800 children with variable degrees of sensorineural hearing loss. Profound and severe degrees of hearing loss were the most prevalent degrees (P <0.05%). The prevalence of consanguineous marriage offspring in the NH group was 42.5%, while in the HL group it was 68.9% (P < 0.05). The differences between both study subgroups regarding the distribution of different degrees of parental consanguinity (first, second, double first, and first once removed cousins) were insignificant (P > 0.05). The relative risk and 95% confidence interval (RR, 95% CI) for development of hearing loss in offspring of consanguineous marriage was 1.76 (95% CI 1.57-1.97, P < 0.001).

Conclusions: There was 76% increased risk for consanguineous marriage progeny to develop SNHL when compared to non consanguineous progeny.

Keywords: Etiology of hearing loss; Genetic hearing loss; Non syndromic hearing loss.