This dataset covers the WFS1 gene variants. The principal investigator systematically characterised variants of four deafness-causing genes among sub-Saharan African populations. Starting with a South African cohort, we aimed to establish the significance of the gene variants, confirm pathogenicity and causality, and to define the phenotypes using a mixed-method approach to elucidate their impact on gene function. The selected genes were MYO7A, TRIOBP, SLC26A5 and WFS1. For this purpose, Sanger sequencing, family studies and segregation analysis, functional studies (electrophysiological measurements using the whole-cell patch-clamp technique on transfected HEK293 cells and immunohistochemical staining), and 3D modelling were combined.