湖北地区原发性先天性青光眼患儿CYP1B1基因的新突变研究

Analysis of the CYP1B1 gene mutation in primary congenital glaucoma patients of Hubei Han nationality

目的探讨湖北地区汉族原发性先天性青光眼（PCG）患儿的基因突变情况并为基因诊断奠定基础。方法对47例无关个体PCG患儿及100例健康正常儿童进行基因分析。采取外周静脉血4ml，制备外周白细胞基因组DNA，参照文献所报道的引物序列，聚合酶链反应（PCR）分别扩增CYP1B1基因的第2、3外显子，琼脂糖凝胶电泳鉴定产物后，应用单链构象多态性（SSCP）、变性高效液相色谱分析（DHPLC）及DNA序列分析技术对患儿和对照组进行基因分析。结果7例PCG患儿呈现CYP1B1基因的第3外显子第385密码子的第1个碱基C→T碱基点突变，致对应的亮氨酸转变为苯丙氨酸（L385F）。这一变异在正常对照组成员中未检出，且检索国内外文献尚未见报道。结论湖北地区汉族PCG患者存在CYP1B1基因第3外显子突变，这一新突变位点位于P450蛋白的重要功能区，可能为病理性突变。在汉族PCG患者中进行CYP1B1基因突变的深入研究并寻找其他致病基因，对探讨PCG发病机制具有重要意义。

Objective To identify novel CYP1B1 gene mutation in primary congenital glaucoma （PCG） patients of Hubei Han nationality and establish the possibility of gene diagnosis of PCG. Methods Forty-seven patients with PCG and 100 normal subjects were studied. Genomic DNA was extracted from the peripheral leukocytes of all subjects. Mutation in exon2 and exon3 of CYP1 B1 gene was detected in patients and control subjects by polymerase chain reaction-single strand conformation polymorphism （PCR-SSCP）, denaturing high performance liquid chromatograph （DHPLC）, and direct sequencing DNA techniques. Results Compared to normal subjects, a novel mutation was first time identified by direct sequencing demonstrating a homozygous C-to-T transition at codon 385 （ CTF to TIT） which produced L385F mutation of CYP1 B1 gene in 7 of the 47 patients with PCG. Conclusions The novel mutation in exon 3 of CYP1B1 found in PCG patients of Hubei Han nationality was probably pathological mutant gene by nature. It is important that further study be conducted to seek for the specific mutations of CYP1B1 gene and underlying pathological mechanism of PCG patients of Han nationality.