摘要
目的 探讨中国人非综合征性学语前聋患者肌球蛋白 7a基因的突变频率和特性。方法 收集非综合征性学语前聋家系 34个 ,大部分来自湖南地区 ,共计 6 5例 ;散发患者 31例 ;健康对照组 10 0例。聚合酶链反应扩增肌球蛋白 7a基因的部分外显子 ,单链构象多态性分析初筛可疑突变者 ,发现异常构象带后再行DNA测序确定是否突变。结果 在 2个患者中检测出肌球蛋白 7a基因 7号外显子的 6 17号核苷酸G→A杂合突变 ,在同一家族的正常人中未发现该突变。该突变发生在肌球蛋白 7a分子的一个保守区段 ,可导致 2 0 6位上的精氨酸改变为谷氨酰胺 (R2 0 6Q )。结论 肌球蛋白 7a基因的R2 0 6Q突变很可能是导致非综合征性学语前聋的一个新突变 。
Objective To ascertain the frequency and characteristics of myosin 7a gene mutations in Chinese with prelingual nonsyndromic hearing impairment. Methods Most of cases were collected within Hunan province, including 31 sporadic congenital deaf patients and 65 patients from 34 hereditary prelingual deafness families, and 100 health individuals were used as control. Genomic DNA was extracted from the patients and subjected to the PCR to amplify selected exons of myosin 7a gene, and then the amplified products were screened for base variations by single strand conformational polymorphismanalysis (SSCP). The bands with abnormal conformation were sequenced to confirm the mutation. Results G to A substitution was detected at nucleotide 617 in exon 7 as hetrozygous state in two patients and was not found in unaffected members in their family. This mutation caused Arg206Gln within a highly conserved heptapeptide sequence of myosin 7a protein, and was close relevant to the prelingual nonsyndromic deafness.Conclusions The Arg206Gln mutation in exon 7 of myosin 7a is possibly a novel mutation to cause prelingual nonsyndromic hearing impairment. Our results provide the evidence that exon 7 of Myosin 7a is a mutational hotspot region in genetic deafness.
出处
《中华耳鼻咽喉科杂志》
CSCD
北大核心
2004年第9期538-542,共5页
Chinese Journal of Otorhinolaryngology
