Advantages of high throughput parallel sequencing in detecting somatic mosaicism in sporadic retinoblastoma

Abstract

Almost 80% of cases of hereditary retinoblastoma do not have a family history and arise as a result of de novo mutations in the RB1 gene. An NGS test was performed on 208 unrelated patients with sporadic RB, including 145 patients with a unilateral form and 63 patients with a bilateral one. In the group of patients with bilateral RB, pathogenic variants in the RB1 gene were detected in 90.5% (57/63) cases. In 4.8% (3/63) of patients, a mosaic variants were determined. In the group of patients with unilateral RB, changes in the RB1 gene were detected in 17.9% (26/145) cases. Among the examined patients, somatic mosaicism was detected in 9.0% (13/165) cases. NGS allows us to determine the allelic frequency of variants, which makes the search for somatic mosaicism effective.