Consanguinity and its association with hearing loss prevalence: a systematic review across populations

Hearing loss is a common disorder that is associated with worsening communication and lower quality of life. Consanguinity, marriage between close relatives, is one of the most common risk factors of hearing loss. However, there is a gap in knowledge about the rate of hearing loss among children with a consanguinity history in different regions. The current systematic review aimed to assess the relation between consanguinity and hearing loss and was conducted among ten studies in different local and international countries. Studies' general characteristics, type of consanguineous marriage, and incidence of hearing loss were the main collected data. A meta-analysis was conducted to estimate the pooled prevalence and risk ratio of developing hearing loss among individuals with consanguinity compared to those without consanguinity. The meta-analysis showed that the pooled prevalence of consanguinity among the individuals was 58.3%, with first-degree consanguinity being the most common type. The pooled prevalence of hearing loss was 54.7%. In addition, the meta-analysis showed that pooled prevalence of consanguinity among 2602 patients with hearing loss was 68 % (95% confidence interval (CI): 51-82%) with a significant heterogeneity between studies (I²=98.6%, P=0.0001). Moreover, the review showed that consanguinity increases the risk of developing hearing loss by 1.47 times (95% CI: 1.38-1.57, P