Reiisi Somayeh, Sanati Mohammad Hosein, Tabatabaiefar Mohammad Amin, Ahmadian Shahla, Reiisi Salimeh, Parchami Shahrbanoo, Porjafari Hamid, Shahi Heshmat, Shavarzi Afsaneh, Hashemzade Chaleshtori Morteza
Medical Genetics Department, National Institute of Genetic Engineering and Biotechnology (NIGEB).
Medical Genetics Department, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Int J Mol Cell Med. 2014 Summer;3(3):176-82.
Sensorineural non-syndromic hearing loss is the most common disorder which affects 1 in 500 newborns. Hearing loss is an extremely heterogeneous defect with more than 100 loci identified to date. According to the studies, mutations in GJB2 are estimated to be involved in 50- 80% of autosomal recessive non-syndromic hearing loss cases, but contribution of other loci in this disorder is yet ambiguous. With regard to studies, DFNB4 locus (SLC26A4) can be classified as the second cause of hearing loss. So, this study aimed to determine the contribution of this locus in hearing loss as well as the frequency of SLC26A4 gene mutations in a population in the west of Iran. In this descriptive laboratory study, we included 30 families from the west of Iran with no mutation in GJB2 gene. Linkage analysis was performed by DFNB4 (SLC26A4) molecular markers (STR). The families with hearing loss linked to this locus were further analyzed for mutation detection. SLC26A4 gene exons were amplified and analyzed using direct DNA sequencing. In studied families, 2 families displayed linkage to DFNB4 locus. Identified mutations include mutation in exon 5 (c.416 G>T) and in splicing site of exon 7 (IVS-2 A>G or c.919-2 A>G).
感音神经性非综合征性听力损失是最常见的疾病，每500名新生儿中就有1人受其影响。听力损失是一种极其异质性的缺陷，迄今为止已确定了100多个基因座。根据研究，GJB2基因突变估计与50%-80%的常染色体隐性非综合征性听力损失病例有关，但该疾病中其他基因座的作用仍不明确。关于研究，DFNB4基因座（SLC26A4）可被归类为听力损失的第二大病因。因此，本研究旨在确定该基因座在听力损失中的作用以及伊朗西部人群中SLC26A4基因突变的频率。在这项描述性实验室研究中，我们纳入了来自伊朗西部的30个家庭，这些家庭的GJB2基因无突变。通过DFNB4（SLC26A4）分子标记（STR）进行连锁分析。对与该基因座相关的听力损失家庭进一步进行突变检测分析。使用直接DNA测序对SLC26A4基因外显子进行扩增和分析。在研究的家庭中，有2个家庭显示与DFNB4基因座连锁。鉴定出的突变包括外显子5中的突变（c.416 G>T）和外显子7剪接位点的突变（IVS-2 A>G或c.919-2 A>G）。
