Detecting Element Insertion Variant in Gene Using Whole Genome Sequencing in Patients with Retinitis Pigmentosa.

element insertion in the exon 4 of the gene was newly identified through whole genome sequencing (WGS). This was not detected in previous next-generation sequencing (NGS) analysis. We report three cases of Korean retinitis pigmentosa (RP) patients with compound heterozygous variants including element insertion in the gene, indicating that element insertion could be a cause of RP; Among patients diagnosed with RP having variants in the gene in the Asan Medical Center, WGS was additionally performed for genetically unsolved cases in previous NGS analysis to detect any presence of element insertion. For cases detected to have element insertion in the exon 4 of the gene, genetic and clinical characteristics were analyzed; : Among 16 patients with RP, 3 patients were detected to have element insertion in the gene. element insertion in the gene was also detected using WGS. It was revealed to be a pathogenic variant. Therefore, gene mutation was the confirmed genetic cause of RP for these three cases and genetic counseling was enabled for them; : element insertion in the gene could be a genetic cause of autosomal recessive RP patients with compound heterozygous variants. Through WGS, the identification of this pathogenic variant was possible. Confirmation is needed to check the presence of element insertion in patients with compound heterozygous variants in the gene.