基因检测在一家族性青光眼家系中的预警作用

目的 探讨基因检测技术对家族性青光眼家系新增成员的早期预警作用.方法 前瞻性队列研究.对一家族性青光眼家系新增成员提取外周血DNA,进行myocilin基因突变筛查,根据基因检测结果将其分为myocilin基因突变携带组和非携带组,并对该家系成员进行前瞻性队列研究,观察其视力、眼压、视野、视乳头结构、视网膜神经纤维层改变情况.结果 在12例家族新增成员中,DNA测序证实5例成员myocilin基因第3外显子呈现C→T杂合突变(Pro370Leu);其余7例成员未显示myocilin基因突变.随访过程中,突变携带组成员均相继诊断为开角型青光眼,视野缺损距眼压升高平均时间为21.6个月,视网膜神经纤维层厚度发生变化距眼压升高平均时间为14.4个月;而非携带组成员在随访过程中眼压、视乳头结构、视网膜神经纤维层、视野均未出现病理性改变.结论 myocilin基因为家族性青光眼的致病基因,基因诊断技术在青光眼家系中所表现的特异性及灵敏性可满足症状前诊断要求并具有预警作用.(中华眼科杂志,2009,45:621-624)

Gene screening as the forewarning measure to predict glaucoma

Objective To investigate the effect of gene screening on forewarning and monitoring of familial open-angle glaucoma pedigree. Methods Comprehensive ophthalmic examinations were performed in all available family members. The genomic DNA was extracted from peripheral blood. The myocilin gene was amplified and screened for mutations using direct sequencing. All family members were followed up. Results Among 12 family members, 5 individuals carry a C to T transition in exon 3 resulting in the substitution of proline to leucine (Pro370Leu), and the other 7 individuals did not carry this mutation. Ophthalmic examinations did not show any abnormality in the optic disc, the thickness of RNFL, and visual field parameters in mutation-carriers. During the follow-up, all carriers were diagnosed as open-angle glaucoma. The mean time of presentation of the defect of visual field was 21.6 months and 14.4 months after the changes in RNFL thickness. Conclusion Genetic diagnosis was proven to be a method with high specificity and sensitivity; and can be used for presymptom diagnosis and forewarning in familial open-angle glaucoma pedigree. (Chin J Ophthalmol , 2009,45:621-624)