Identifying two pathogenic variants in a patient with pigmented paravenous retinochoroidal atrophy.

Little is known about the genetic background of pigmented paravenous retinochoroidal atrophy (PPRCA) due to rarity of patients. In this study, we identified two pathogenic variants in in a 2-year-old boy with PPRCA screened by whole-exome sequencing (WES). The patient presented to our department with photophobia for 17 months, and then he underwent fundus photography and fluorescein fundus angiography. Genomic DNA was extracted from peripheral blood of the proband and the parents. Trio-WES strategy was utilized to identify the causal variants from the proband and the parents, followed by validation based on Sanger sequencing. The patient was finally diagnosed with PPRCA after differential diagnosis. Two heterozygous pathogenic variants were detected by WES according to the American college of medical genetics and genomics guidelines, including NM_020366.4: c.2592T > G: p.Y864* and NM_020366.4: c.154C > T: p.R52* in located in exon 17 and exon 3, leading to termination codon, respectively. This is the first study reporting pathogenic variants within as causal for PPRCA.