Genetic Causes of Deafness and Communication Disabilities in Sokoto State: A Community Genetics Survey

Hearing loss is one of the most common sensory impairments worldwide, with genetic causes accounting for a significant proportion of congenital and early-onset cases. In Sokoto State, North West Nigeria, community-level data on the genetic basis of deafness remain scarce despite observed familial clustering in some communities. This community-based genetics survey aimed to identify families with hereditary deafness, document pedigree structures, and assess GJB2 gene carrier frequency as a representative genetic cause. Systematic house-to-house surveys were conducted in three local government areas, identifying 45 families with at least two affected members across two generations. Affected individuals and their parents consented to molecular analysis. Genomic DNA was extracted from buccal swabs, and GJB2 exon 2 was Sanger-sequenced. In addition, the del(GJB6-D13S1830) deletion was screened by PCR. GJB2 pathogenic variants were identified in approximately 30 percent of sequenced families, predominantly as the 35delG frameshift mutation. The finding of GJB2-negative families with clear autosomal recessive inheritance suggests additional genetic heterogeneity requiring comprehensive panel testing. Keywords: hereditary deafness, GJB2 gene, connexin 26, Sokoto State, community genetics