GJB2 and MTRNR1 contributions in children with hearing impairment from Northern Cameroon

Objective: the aim of this work was to evaluate the possible different impacts of genetic and environmental factors in childhood deafness in northern Cameroon. GJB2 mutations are responsible for more than half of all cases of prelingual nonsyndromic recessive deafness in Caucasians, representing the most important deafness-causing factor in the industrialized world. Other genes such as MTRNR1 are also involved. In sub-Saharan Africa, environmental factors seem to dominate genetic contributions, but few studies on the etiology of deafness in Africa are available for comparison. Design: prospective cross sectional study. Study Sample: we performed a molecular screen of the GJB2 and MTRNR1 genes in 70 deaf children and 67 unaffected controls in Maroua (Cameroon) and a literature analysis focused on deafness epidemiology in developing countries. Results: no GJB2 mutations emerged, and only a single MTRNR1 variant that may be pathogenic was found. Conclusion: environmental factors turn out to be more relevant than genetic factor in the Maroua population.