原发性开角型青光眼MYOC- TIGR基因突变研究

目的 筛选并研究原发性开角型青光眼(POAG)小梁网糖皮质激素诱导反应蛋白MYOC- TIGR基因突变情况。方法 病例对照研究。抽取2002年1至12月就诊并诊断为POAG患者118例和150例非POAG对照者的外周静脉血4～8ml,采用酚-氯仿抽提全基因组DNA,应用聚合酶链反应(PCR)技术扩增全基因组DNA,以单核苷酸构象多态性(SSCP)分析MYOC基因的3个外显子（7对引物）编码区域序列改变。对SSCP分析异常者,采用双向测序法进一步证实。应用Cfr13I、Hinfl及BsmA1等限制性内切酶检测对照者MYOC基因编码区序列改变。POAG与非POAG人群MYOC基因各位点突变率比较采用x2检验。结果 基因序列分析发现G12R、I288M及Y353I共3个基因序列改变。118例POAG患者中仅有5例(4.23％)发生G12R位点突变,150例对照者中未见G12R位点改变;两组G12R位点突变率比较差异有统计学意义(x2=4.37,P=0.037)。POAG组和对照组均有I288M和Y353I位点改变,但两组突变率比较差异无统计学意义(x2=0.07,P=0.791和x2=0.56,P=0.453)。POAG患者基因突变率4.23％。结论 MYOC基因突变可能与POAG发病有关,MYOC基因突变可能是POAG发病的分子机制之一。

Study on MYOC/TIGR gene mutations in primary open-angle glaucoma

Objective To study the mutations in the trabecular meshwork induced- glucocorticoid response protein gene (TIGR/MYOC) in Chinese POAG patients. Methods It was a case-control study.One hundred and eighteen Chinese patients with POAG and 150 control subjects without POAG were screened for coding sequence of the MYOC gene by polymerase chain reaction, single-strand conformation polymorphism (SSCP) and DNA sequence. Restriction endonuclease analysis was used to detect the SSCP in 150 gender- and aged-matched controls. Statistical significance of the difference in frequencies of MYOC mutations between POAG patients and the controls was determined by the chi-squared test. Results Three coding sequence variants that lead to amino acid changes were identified in MYOC gene. One mutation of MYOC gene was novel, I288M, which was present in one patient with POAG and 3 control subjects. G12R and Y353I have been reported previously. I288M and Y353I were found in both the subjects with and without POAG, the difference of the frequency of these two mutations between POAG and the controls was x2 =0. 07, P =0. 791 and x2 = O. 56, P = 0. 453, respectively. Coding sequence mutations of MYOC were found in 4. 23％ POAG patients. Frequency of G12R mutation in POAG patients was significantly greater than that in the controls (x2 = 4. 37, P = 0. 037). Conclusions One novel variant locus in the MYOC/TIGR (I288M) was found in the present study, but this mutation is not associated with POAG. G12R is the most common mutation in MYOC locus in Chinese subjects with POAG. Approximately 4. 23％ sporadic POAG patients have mutation in the exon 1 in MYOC/TIGR.