Supplementary Material for: A Novel GUCY2D Frameshift Deletion Identified in a Patient with Leber Congenital Amaurosis 1: A Case Report

Introduction: This study aimed to describe the clinical characteristics of a 1-year-old male patient with Leber congenital amaurosis type 1 (LCA1) and investigate the genetic variations underlying his symptoms.

Case Presentation: A comprehensive medical history of the patient was obtained with thorough examinations via mydriatic optometry, fundus photography, and flash electroretinography. To identify causative mutations, whole-exome sequencing (WES) was conducted. Potential pathogenic mutations identified with WES were further validated via Sanger sequencing, which was also performed on family members to confirm the origins of the mutations. Based on clinical and laboratory findings, the patient was diagnosed with LCA1. Two heterozygous mutations in the GUCY2D gene, c.835G>A and c.2516_2517del, were detected in the patient with WES. Both mutations were assigned as likely pathogenic according to ACMG guidelines. c.2516_2517del has not been described previously. Sanger sequencing confirmed that the unaffected father and mother carried c.835G>A and c.2516_2517del, respectively.

Conclusion: The patient was a typical case of LCA1 with two GUCY2D mutations. To the best of our knowledge, this is the first report of the allele mutation c.2516_2517del in a patient with LCA1.