一个非综合征型聋家系MITF基因致病性新突变

A Novel Heterozygous Missense MITF Variant Causes Human Autosomal Dominant Inheritance of Nonsyndromic Hearing Loss

高玲丽;潘春晨;鲍坚强;孙敬武;

1:中国科学技术大学生命科学与医学部附属第一医院耳鼻咽喉头颈外科

2:中国科学技术大学生命科学与医学部附属第一医院生殖医学中心

摘要
目的 研究一个非综合征型聋家系的致病基因突变。方法 通过家系调查、临床检查和遗传学特征分析,对一个非综合征型聋家系的临床表型及致病原因进行分析,提取家系成员的外周血DNA,应用遗传性耳聋基因芯片结合耳聋基因靶向测序筛选致病基因,然后利用Sanger测序对发现的致病基因位点进行验证,分析该突变位点在各物种中的保守性及该突变位点所在的结构域;通过Swiss model工具进行同源建模模拟蛋白质的三维结构,观察MITF基因突变前后对蛋白功能的影响;利用蛋白功能预测软件REVEL进行变异致病性的预测。结果 该家系包含3代15人,先证者(Ⅲ-4)、姐姐(Ⅲ-3)、母亲(Ⅱ-4)及外婆(Ⅰ-4)4人被诊断为先天性双侧感音神经性聋,未发现皮肤毛发色素改变、虹膜异色、内眦间距异常、上肢异常、巨结肠等;父亲(Ⅱ-3)及其他家属(Ⅱ-5)表型正常。9项遗传性耳聋基因芯片筛查未发现致病突变;耳聋基因靶向测序结果显示先证者携带MITF基因的一个单杂合变异:MITF:c.730G>A(p.Gly244Arg, NM_000248),Sanger测序结果验证了先证者(Ⅲ-4)、患者Ⅰ-4、Ⅱ-4、Ⅲ-3的MITF基因c.730G>A(p.Gly244Arg, NM_000248)突变,变异来源于母亲,父亲未发现该位点的变异;该变异为杂合错义突变,在各物种中高度保守并位于bHLH-Zip结构域。Swiss model预测的蛋白质三维结构图显示,该位点突变可能通过影响MITF基因与非特异性DNA的结合从而影响该蛋白质的功能。REVEL分析结果为D(预测为有害),提示可能为一个潜在的致病位点。结论 MITF基因c.730G>A(p.Gly244Arg, NM_000248)位点可能为该非综合征型聋家系的致病突变。
关键词
非综合征型聋;MITF基因;基因突变;Sanger测序
基金项目(Foundation):
国家自然科学基金青年科学基金项目(81800911);; 安徽省自然科学基金面上项目(1808085QH248);; 科大新医学培育项目(WK9110000053)
作者
高玲丽;潘春晨;鲍坚强;孙敬武;
参考文献

1 王秋菊,王洪阳.常染色体显性遗传性耳聋(2)[J].听力学及言语疾病杂志,2016,24(3):317-320.

2 Hereditary Hearing Loss Homepage.2020.https://www.aho.int/news-room/fact-sheets/detail/deafness-and-hearing-loss.

3 戴朴,于飞,韩冰,等.中国不同地区和种族重度感音神经性聋群体热点突变的分布和频率研究[J].中华耳鼻咽喉头颈外科杂志,2007,42(11):804-808.

4 Pingault V,Ente D,Dastot-Le MF,et al.Review and update of mutations causing Waardenburg syndrome[J].Hum Mutat,2010,31(4):391-406.

5 Zhang Z,Chen QD,Zhao LP,et al.A novel variant in MITF in a child from Yunnan-Guizhou Plateau with autosomal dominant inheritance of nonsyndromic hearing loss:a case report[J].Mol Med Rep,2018,17(4):6054-6058.

6 Thongpradit S,Jinawath N,Javed A,et al.MITF variants cause nonsyndromic sensorineural hearing loss with autosomal recessive inheritance[J].Sci Rep,2020,10(1):12712-12712.

7 Cheli Y,Giuliano S,Botton T,et al.Mitf is the key molecular switch between mouse or human melanoma initiating cells and their differentiated progeny[J].Oncogene,2011,30(20):2307-2318.

8 Goding CR,Arnheiter H.MITF-the first 25 years[J].Genes Dev,2019,33(15-16):983-1007.

9 Zhang W,Dai M,Fridberger A,et al.Perivascular-resident macrophage-like melanocytes in the inner ear are essential for the integrity of the intrastrial fuid-blood barrier[J].Proc Natl Acad Sci USA,2012,109(26):10388-10393.

10 Kawakami A,Fisher DE.The master role of microphthalmia-associated transcription factor in melanocyte and melanoma biology[J].Lab Invest,2017,97(6):649-656.

11 Soura E,Eliades PJ,Shannon K,et al.Hereditary melanoma:update on syndromes and management:Emerging melanoma cancer complexes and genetic counseling[J].J Am Acad Dermatol,2016,74(3):411-420.

12 Vetrini F,Auricchio A,Du J,et al.The microphthalmia transcription factor (Mitf) controls expression of the ocular albinism type 1 gene:link between melanin synthesis and melanosome biogenesis[J].Mol Cell Biol,2004,24(15):6550-6559.

13 Pogenberg V,Ogmundsdóttir MH,Bergsteinsdóttir K,et al.Restricted leucine zipper dimerization and specifcity of DNA recognition of the melanocyte master regulator MITF[J].Genes Dev,2012,26(23):2647-2658.

14 Steingrímsson E,NⅡ A,Fisher DE,et al.The semidominant Mi(b) mutation identifies a role for the HLH domain in DNA binding in addition to its role in protein dimerization[J].EMBO J,1996,15(22):6280-6289.