Objective: To perform molecular diagnosis and genetic counseling in a young Chinese couple with congenital hearing loss.
Methods: Variant screening analysis was performed by PCR and direct Sanger sequencing or targeted next-generation sequencing of all known hearing loss genes. Novel variants were evaluated by PolyPhen2 and PROVEAN software tools to evaluate possible effects on protein function.
Results: We identified causative variants in the young couple: c.235delC (rs80338943)/c.299-300delAT (rs111033204) compound heterozygous variants of GJB2 in the husband and c.1828G>A (p.Glu610Lys, rs535637788)/c.2825-2827delAGA compound heterozygous variants of LOXHD1 in the wife. The LOXHD1 c.1828G>A variant has only previously been reported in a Mexican-American individual in the 1000 Genomes Project database. Using PolyPhen2 and PROVEAN, we speculated that the LOXHD1 variant c.1828G>A is potentially pathogenic.
Conclusion: We carried out molecular diagnosis in a young couple with congenital hearing loss, and identified different disease-causing genes in the two individuals. The LOXHD1 variant c.1828G>A present in the wife had not previously been reported in individuals with congenital hearing loss. We determined this to be a potential pathogenic variant, and a novel variant associated with hearing loss in a Chinese individual.
Keywords: DFNB77; Hearing loss; LOXHD1; Sanger sequencing; genetic counseling; next-generation sequencing.