Genetic Linkage Analysis of the DFNB63 Locus in Families with Autosomal Recessive Nonsyndromic Hearing Loss from Hamadan and Kohgiluyeh and Boyer-Ahmad Provinces, Iran

Hearing loss is a sensorineural impairment and is one of the most widespread congenital impairments with a prevalence of one in thousand among children. Studies have shown that 50 percent of congenital hearing loss have genetic causes and the remaining 50 percent are due to environment and unknown reasons; in addition, it is noted that this impairment is very heterogeneous. Almost 70 percent of cases are nonsyndromic with hearing loss presenting as the only impairment. About 80 percent of this type of hearing loss is inherited in recessive manner (ARNSHL). In this study, we determined the role of DFNB63 locus in a series of families in two western provinces of Iran. In this descriptive-laboratory study, to determine the prevalence of DFNB63 mutations in western provinces of Iran, we studied 150 individuals from 30 families in Hamadan and Kohgiluyeh and Boyer-Ahmad provinces. The selected families in this study were consanguineous, had at least 2 patients, and were negative for GJB2 mutations. Linkage analysis was performed using six appropriate short tandem repeats (STR) markers. With linkage analysis of selected families, no family was shown to be linked to the DFNB63 locus. It was shown that the LRTOMT mutations played no role in causing hearing loss in the studied families. The present study suggests that LRTOMT mutations may not be clinically important in causing autosomal recessive nonsyndromic hearing loss in the investigated provinces.