COL7A1基因在营养不良性大疱性表皮松解症的突变研究

The COL7A1 gene mutations in dystrophic epidermolysis bullosa

目的探讨COL7A1基因在营养不良性大疱性表皮松解症中突变的基因型与临床表型的关系。方法收集14例营养不良性大疱性表皮松解症家系,皮肤活检进行常规组织病理、免疫荧光及电镜检查,采集外周血,提取基因组DNA进行COL7A1基因突变筛查。结果显性遗传型中的3个家系为COL7A1基因错义突变所致,泛发性隐性遗传型中4个家系结合了两个提前终止密码子突变,另外3个结合一个提前终止密码子和剪切位点或甘氨酸错义突变,3个局限性隐性遗传型家系则由提前终止密码子和错义突变引起。结论显性遗传型由甘氨酸错义突变所致,隐性遗传型则包括无义突变、剪切位点突变、插入或缺失突变等。

Objective To study the genotype-phenotype correlation of dystrophic epidermolysis bullosa with COL7A1 mutations. Methods 14 dystrophic epidermolysis bullosa families were collected, and immunofluorescence and elec- tron microscopy were processed from skin biopsies. Venous blood samples were collected and genomic DNA was ex- tracted. COLTA1 was screened for sequence mutations. Results Three dominant cases resulted from COLTA1 missense mutation. Among Hallopeau-Sieme cases, four combined two premature termination codon （PTC） mutations and three combined PTC and spice-site or glycine substitution variants. PTC and missense mutation resulted in non Hallopeau-Sieme cases in our study. Conclusion The dominant type usually involves glycine substitutions, while the recessive type involves nonsense, splice site. internal deletions or insertions mutations.