Department of Ocular Genetics; Department of Pediatric Ophthalmology, Strabismus and Neuro-ophthalmology, Dr Shroff's Charity Eye Hospital, Daryaganj, New Delhi, India.
Department of Ocular Genetics, Dr Shroff's Charity Eye Hospital, Daryaganj, New Delhi, India.
Indian J Ophthalmol. 2022 Jul;70(7):2280-2292. doi: 10.4103/ijo.IJO_2255_21.
Congenital aniridia is a pan ocular disorder characterized by partial or total loss of iris tissue as the defining feature. Classic aniridia, however, has a spectrum of ocular findings, including foveal hypoplasia, optic nerve hypoplasia, nystagmus, late-onset cataract, glaucoma, and keratopathy. The latter three are reasons for further visual compromise in such patients. This entity is often due to mutations in the PAX6 (Paired box protein Pax-6) gene. Recently, aniridia-like phenotypes have been reported due to non-PAX6 mutations as in PITX2, FOXC1, FOXD3, TRIM44, and CYP1B1 as well wherein there is an overlap of aniridia, such as iris defects with congenital glaucoma or anterior segment dysgenesis. In this review, we describe the various clinical features of classic aniridia, the comorbidities and their management, the mutation spectrum of the genes involved, genotype-phenotype correlation of PAX6 and non-PAX6 mutations, and the genetic testing plan. The various systemic associations and their implications in screening and genetic testing have been discussed. Finally, the future course of aniridia treatment in the form of drugs (such as ataluren) and targeted gene therapy has been discussed.
先天性无虹膜是一种全眼球疾病，其特征为部分或全部虹膜组织缺失。然而，经典的先天性无虹膜具有一系列眼部表现，包括黄斑发育不良、视神经发育不良、眼球震颤、迟发性白内障、青光眼和角膜病变。后三种是导致此类患者视力进一步受损的原因。该疾病通常是由于 PAX6（配对盒蛋白 Pax-6）基因突变引起的。最近，由于非 PAX6 基因突变，如 PITX2、FOXC1、FOXD3、TRIM44 和 CYP1B1 等，也报道了类似无虹膜的表型，其中存在无虹膜的重叠表现，例如伴有先天性青光眼或眼前段发育不良的虹膜缺陷。在这篇综述中，我们描述了经典无虹膜的各种临床特征、合并症及其管理、相关基因的突变谱、PAX6 和非 PAX6 突变的基因型-表型相关性，以及基因检测计划。讨论了各种全身相关性及其在筛查和基因检测中的意义。最后，还讨论了无虹膜治疗的未来发展方向，包括药物（如 ataluren）和靶向基因治疗。
