Molecular genetic and pathophysiological study of new hereditary retinal diseases.

“隐匿性黄斑营养不良”是我们发现的一种新的临床类型，本文对36例隐匿性黄斑营养不良患者的临床特点进行了研究。8个家系为常染色体显性遗传。视力范围为0.1 ~ 1.0，多数患者表现为红绿色觉缺陷。眼底和荧光血管造影均正常，但OCT的详细分析表明，多数患者黄斑厚度明显变薄，我们认为ERG阴性的先天性静止性夜盲可分为完全型和不完全型两种不同的临床类型。我们的假设被分子遗传学证明是正确的。我们研究了90例患者的分子遗传学和几种视觉功能。完全型患者中约有一半出现NYX基因突变，不完全型患者均出现CACNA 1F基因突变。ERG结果表明，完全型视网膜病变存在ON双极细胞的选择性功能障碍，而不完全型视网膜病变则存在ON和OFF双极细胞的不完全功能障碍，并且我们研制的黄斑部ERG记录系统提示，完全型视网膜病变黄斑部的功能不同于视网膜的其它部分。这一结果可能合理地解释了许多患者尽管ON视觉通路完全缺陷，但仍表现出正常的色觉和接近正常的对比敏感度。

"Occult macular dystrophy" is a new clinical entity detected by us and the clinical characteristics of 36 patients was studied. The autosomal dominant inheritance was suggested in 8 families. The visual acuity ranged from 0.1 to 1.0 and many patients showed red-green color vision deficiency. The fundi and fluorescein angiography were normal, however the detail analysis of OCT indicated that the thickness of the macula is significantly thinner than normal in many patients.We demonstrated that the congenital stationary night blindness with negative ERG is classified into two subtypes, complete and incomplete type, which are different clinical entities. Our hypothesis was proven true by molecular genetics. We studied 90 patients in terms of the molecular genetics and several visual functions. About half of the patients with complete type, the NYX gene mutation was shown, and all incomplete type patients showed CACNA1F gene mutation. The ERG findings indicated that the complete type has the selective dysfunction of the ON bipolar cell, while incomplete type has the incomplete dysfunction of both ON and OFF bipolar cells.Furthermore, the focal macular ERG recording, which we have developed suggested that the function of macula is different from other part of the retina in complete type. This result may be reasonable to explain that many patients show normal color vision and near normal contrast sensitivity in spite of the complete defect of ON visual pathway.