MOLECULAR SCREENING METHODS FOR DIFFERENT TYPES OF GLAUCOMA

青光眼是一组遗传性眼部疾病，在美国和世界范围内，青光眼占所有失明的3%。近年来，已经确定了7个青光眼基因座的染色体位置（其中5个是我们发现的，2个是其他小组发现的）。此外，我们和另一个研究小组最近分别在原发性先天性和原发性开角型青光眼分离家族中发现了两个独立基因的首次突变，即编码细胞色素P4501B1 （CYP1B1）和小梁网诱导糖皮质激素反应蛋白（TIGR）的基因。从那时起，这两个基因在这两种类型青光眼的病因学中的作用已被其他研究人员和其他人群证实。到目前为止，我们已经在家族性和散发性原发性先天性青光眼病例中发现了16个新的CYP1B1突变，在原发性开角型青光眼家族中发现了6个新的TIGR突变。鉴于这些发现，我们相信在青光眼不可逆视神经损伤发生之前，使用这些分子方法识别有这些疾病风险的受试者是可行的。因此，本项目的具体目的是：1)从康涅狄格州眼科招募的大量青光眼患者（N = 500）进行识别、确定和临床检查；2)采集这些个体的血液或口腔组织样本，提取并储存DNA；3)系统筛选这些患者的DNA中CYP1B1和TIGR这两个已知在青光眼中具有病因学意义的基因；4)从这些患者的DNA中筛选其他基因的突变，这些突变随后被确定为青光眼的病因学意义；5)将受影响受试者的突变类型（基因型）与临床数据（表型）联系起来。GCRC将有助于这些个体的识别、确定和临床检查；在样品采集和处理方面；在突变筛选方面，这是基于我们实验室和其他研究人员的实验室正在进行的工作，他们活跃在这个快速发展的研究领域。

Glaucoma represents a group of inherited eye disorders that collectively accounts for 3% of all blindness in the US and worldwide. In recent years, the chromosomal locations of seven glaucoma loci have been identified (five of which were identified by us and two by other groups). Further, we and another group recently described the first mutations in two independent genes, namely that encoding Cytochrome P4501B1 (CYP1B1) and the Trabecular Meshwork -Induced Glucocorticoid Response protein (TIGR), in families segregating for primary congenital and primary open angle types of glaucoma, respectively. Since then, the role of these two genes in the etiology of these two types of glaucoma has been confirmed by other investigators and in other populations. To date, we have identified 16 novel CYP1B1 mutations in familial and sporadic cases with primary congenital glaucoma and six new TIGR mutations in families with primary open angle glaucoma. Given these findings, we believe it is now feasible to use these molecular methods to identify subjects at risk for these conditions before the irreversible optic nerve damage of glaucoma has occurred. Therefore, the specific aims of this project are: 1) To identify, ascertain, and clinically examine a large sample of glaucoma patients (N = 500) recruited from ophthalmology practices in Connecticut; 2) To obtain blood or buccal tissue samples from these individuals and to extract and bank the DNA; 3) To systematically screen DNA from these patients for the two genes, CYP1B1 and TIGR, which are known to be of etiologic significance in glaucoma; 4) To screen DNA from these patients for mutations in other genes that are subsequently identified as being of etiologic significance in glaucoma; and 5) To correlate the type of mutation (genotype) with the clinical data (phenotype) in affected subjects. The GCRC will be instrumental in the identification, ascertainment and clinical examination of these individuals; in sample collection and processing; and in mutation screening, which is based upon ongoing work in our laboratory and the laboratories of other investigators who are active in this rapidly- developing area of research.