Erbe Christy B, Harris Kevin C, Runge-Samuelson Christina L, Flanary Valerie A, Wackym Phillip Ashley
Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, U.S.A.
Laryngoscope. 2004 Apr;114(4):607-11. doi: 10.1097/00005537-200404000-00003.
OBJECTIVES/HYPOTHESIS: Mutations in the connexin 26 (Cx26) or gap junction beta 2 gene are the leading cause of hereditary nonsyndromic sensorineural hearing loss in Caucasians. The Cx26 coding region of 68 children with nonsyndromic sensorineural hearing loss was sequenced to determine the frequency and type of Cx26 mutations in this population. Screening was also performed for a common connexin 30 (Cx30) or gap junction beta 6 mutation (del [GJB6-D13S1830]). Children also underwent audiological testing to determine whether any correlation exists between Cx26 mutations and severity of hearing loss.
In all, 68 children with nonsyndromic sensorineural hearing loss were screened for Cx26 and Cx30 mutations by polymerase chain reaction and direct sequencing.
Genomic DNA was amplified by polymerase chain reaction using primers that flank the entire Cx26 coding region. Screening for the 342-kb Cx30 deletion was performed using primers that amplified the breakpoint junction of the deletion. The amplicons were then sequenced in both directions and analyzed for mutations. Audiometric testing, including pure-tone audiometry and auditory evoked brainstem response, was also performed to determine the degree of hearing loss.
Twenty-seven of 68 children tested had mutations in Cx26 with 35delG being the most prevalent. Ten additional Cx26 mutations were detected including a novel compound heterozygote. Two children were heterozygous for the Cx30 del (GJB6-D13S1830) mutation.
Cx26 and Cx30 mutations were present in 41.2% of children tested in the study population. Audiometric data supported previous studies demonstrating a greater degree of hearing loss in subjects who are homozygous for the 35delG mutation.
目的/假设：连接蛋白26（Cx26）或缝隙连接蛋白β2基因的突变是白种人遗传性非综合征性感音神经性听力损失的主要原因。对68名非综合征性感音神经性听力损失儿童的Cx26编码区进行测序，以确定该人群中Cx26突变的频率和类型。还对常见的连接蛋白30（Cx30）或缝隙连接蛋白β6突变（del[GJB6-D13S1830]）进行了筛查。儿童还接受了听力测试，以确定Cx26突变与听力损失严重程度之间是否存在任何相关性。
总共对68名非综合征性感音神经性听力损失儿童进行了聚合酶链反应和直接测序，以筛查Cx26和Cx30突变。
使用侧翼覆盖整个Cx26编码区的引物通过聚合酶链反应扩增基因组DNA。使用扩增缺失断点连接的引物对342kb的Cx30缺失进行筛查。然后对扩增子进行双向测序并分析突变情况。还进行了听力测试，包括纯音听力测定和听觉诱发电位脑干反应，以确定听力损失程度。
68名受试儿童中有27名Cx26发生突变，其中35delG最为常见。另外检测到10种Cx26突变，包括一种新的复合杂合子。两名儿童为Cx30 del（GJB6-D13S1830）突变的杂合子。
在研究人群中，41.2%的受试儿童存在Cx26和Cx30突变。听力测试数据支持了先前的研究，表明35delG突变纯合子受试者的听力损失程度更大。
