The pathogenicity of a novel frame-shift variant c.2321delC of PROM1 in an autosomal recessive cone-rod dystrophy pedigree may be associated with augment of autophagy

Abstract

PROM1 gene mutations are increasingly recognized as significant contributors to inherited retinal diseases, demonstrating considerable heterogeneity in mutation loci and types. In our investigation of a Chinese pedigree presenting with autosomal recessive cone-rod dystrophy, we identified two compound heterozygous frame-shift variants of the PROM1 gene: c.1645-1648del (p.K549Qfs∗3) and c.2321delC (p.A774Vfs∗2). We focused on elucidating the pathogenicity and underlying mechanisms of the novel c.2321delC variant. Following the American College of Medical Genetics and Genomics (ACMG) standards and guidelines, this novel variant was assessed as likely pathogenic. Cellular assays demonstrated that the mutated protein exhibited aberrant subcellular localization and decreased stability compared to wild-type counterparts. Notably, cellular models revealed significant autophagic activation evidenced by elevated LC3II/I ratios, while apoptosis markers remained unaffected. Despite preserved apoptotic pathways, the variant induced marked cellular viability impairment.