The role of genetic counseling in the prevention of hearing loss in Iranian patients

Background and Aim : Hearing loss (HL) is one of the most common congenital impairments with a prevalence of 1 in 1000 births. More than half of these cases are caused by genetic factors. Genetic HL shows autosomal dominant, autosomal recessive, X-linked and mitochondrial inheritance patterns. Most cases of genetic deafness (70% to 80%) are nonsyndromic. At the present time, more than 400 genes have been identified to be associated with syndromic and nonsyndromic HL. Because of high rate of consanguine marriages in Iran, autosomal recessive HL is common in our country, and it is estimated that genetic HL consist of more than 70% of cases. Accurate genetic counseling in families with affected children can be very important in identifying the pattern of inheritance and finding its genetic cause. In this study, for more than 700 patients affected by deafness, genetic counseling was done and 380 patients selected for genetic analysis.Methods : Genetic counseling has been set up in 11 cochlear implantation centers in Iran by the charity foundation for hearing rehabilitation (Bakhshesh) to evaluate the families who have candidate children for cochlear implantation. After drawing up the pedigree and evaluating the history of disease in the families, molecular studies were performed for selected patients. In first step GJB2 was screened using Sanger sequencing method. Then, negative samples were analyzed using NGS techniques.Results : In this paper, we are reporting the most common genes and mutations involved in HL in our country.Conclusion : Genetic counseling and testing can be very important in managing and preventing the birth of deaf children in families with affected members. Thus, the Bakhshesh foundation started its thorough work as a non-profit non-governmental organization in 2016 with the aim to aid needy candidates for cochlear implantation and genetic counseling and testing.

کلیدواژه ها:

Autosomal recessive ، non-syndromic ، hearing loss ، genetic counseling