Personalized diagnosis and management of congenital cataract by next-generation sequencing

Purpose: To assess the utility of integrating genomic data from next-generation sequencing and phenotypic data to enhance the diagnosis of bilateral congenital cataract (CC).

Design: Evaluation of diagnostic technology.

Participants: Thirty-six individuals diagnosed with nonsyndromic or syndromic bilateral congenital cataract were selected for investigation through a single ophthalmic genetics clinic.

Methods: Participants underwent a detailed ophthalmic examination, accompanied by dysmorphology assessment where appropriate. Lenticular, ocular, and systemic phenotypes were recorded. Mutations were detected using a custom-designed target enrichment that permitted parallel analysis of 115 genes associated with CC by high-throughput, next-generation DNA sequencing (NGS). Thirty-six patients and a known positive control were tested. Suspected pathogenic variants were confirmed by bidirectional Sanger sequencing in relevant probands and other affected family members.

Main outcome measures: Molecular genetic results and details of clinical phenotypes were identified.

Results: Next-generation DNA sequencing technologies are able to determine the precise genetic cause of CC in 75% of individuals, and 85% patients with nonsyndromic CC were found to have likely pathogenic mutations, all of which occurred in highly conserved domains known to be vital for normal protein function. The pick-up rate in patients with syndromic CC also was high, with 63% having potential disease-causing mutations.

Conclusions: This analysis demonstrates the clinical utility of this test, providing examples where it altered clinical management, directed care pathways, and enabled more accurate genetic counseling. This comprehensive screen will extend access to genetic testing and lead to improved diagnostic and management outcomes through a stratified medicine approach. Establishing more robust genotype-phenotype correlations will advance knowledge of cataract-forming mechanisms.