Candidate Genes for Non-Syndromic Pediatric Cataracts

Introduction: Pediatric cataracts are a significant cause of vision loss in children and may present in isolation or in association with other ocular or systemic diseases. Despite advances in molecular diagnostics, the underlying etiology of cataracts in most patients remains unknown, even in the setting of a positive family history. Genetic testing for pediatric cataracts is neither standardized nor widely utilized. Lack of standardization is multifold, including limited published clinical and experimental reports and the absence of a comprehensive list of candidate genes with grading of the strength of gene-disease relationships. Areas Covered: The purpose of this review is to provide a comprehensive list of the 81 candidate genes potentially associated with non-syndromic pediatric cataracts and the accompanying case-based and experimental literature support in order to start the process of developing a standardized approach to genetic testing. Inheritance patterns, other associated ocular findings, and proposed mechanisms of pathogenesis will be described for the candidate genes. Genes that are associated with two distinct phenotypes, one syndromic and one characterized by non-syndromic cataracts, will also be presented. The types of cataracts and age of onset are often highly variable at both the gene and variant level, so they will not be the focus of this review, but are of interest for future studies. Future Work: Future work is needed to formalize a standardized list of established and candidate genes for non-syndromic pediatric cataracts and to systematically grade our confidence in the gene-disease relationships through the ClinGen framework. An improvement in genetic testing for pediatric cataracts will improve clinical care of these patients and their families regarding prognostication, personalized medical management, and clarification of recurrence risk for reproductive decision making. Further, a better understanding of the pathogenesis of pediatric cataracts can lead to targets for novel treatment development. Keywords: congenital cataracts, pediatric cataracts, ocular genetics, isolated cataracts, inherited eye diseases