Sickle Cell Trait, Malaria and Sensorineural Hearing Loss–A Case-Control Study from São Tomé and Príncipe

Abstract

Background: Hearing loss is a problem with higher incidence in South Asia, Asia Pacific and sub-Saharan Africa. In these countries there is also associated history of anemia and malaria. Objective: This study aims to identify a putative role of Beta globin mutation - sickle cell trait and HL in São Tomé and Príncipe population. Methods: A retrospective case-control study of a convenience sample was collected during Otolaryngologist Humanitarian Missions in São Tomé and Príncipe. Control group includes individuals with normal hearing in both ears, and the case group has participants presenting bilateral or unilateral HL. It was evaluated the potential risk factors and sickle cell trait with HL, as well self-report of malaria infection, consanguinity, familial history of HL. The HbS gene point mutation (Glu6Val) was determined by PCR-RFLP. Results: Our results showed a statistical significance between HL - oral language and self-report of HL. Taken altogether, our data did not reveal association between sickle cell trait and HL. However, a statistical association between HL and self-report of malaria was found. Conclusion: No association between sickle cell trait and the high prevalence of HL was found. Self-report of Malaria was found as a risk factor for the development of HL in São Tomé and Príncipe population. The multifactorial profile of HL shall not exclude the relevance of other etiologic factors than Malaria to justify the high prevalence of HL in São Tomé and Príncipe and further investigation must be applied.