Genetic Linkage Analysis of the DFNB21 Locus in Autosomal Recessive Hearing Loss in Large Families from Khuzestan Province

Background: Hearing loss (HL) is the most common congenital defect in humans. One or two in thousand newborn babies have prelingual hearing loss. Autosomal recessive non-syndromic hearing loss (ARNSHL) is the most common form of hereditary deafness. Hearing loss is more common in the developing countries which is due to genetic and environmental (cultural -health factors) reasons. HL has a wide range of clinical demonstrations including: congenital or late onset, conductive or sensoryneural, syndromic or non-syndromic hearing loss. The goal of this project is to determine the portion of the DFNB21 (TECTA) in ARNSHL in families with negative GJB2 gene in Khuzestan province. Materials and Methods: We studied 21 families with ARNSHL with at least 4 patients and negative for GJB2 mutations from Khuzestan province. Genetic linkage analysis was performed using STR markers linked to DFNB21 locus. Results: Following genetic linkage analysis and haplotyping, out of 21 families with ARNSHL, one family showed linkage to the DFNB21 (TECTA) locus. Conclusion: The results of this project confirm other studies in Iran and give insight into the most common loci causing ARNSHL in Iran which could be helpful in research and clinic.