New mutation in PTEN identified in patient with rare bilateral choroidal ganglioneuroma

Abstract

Background: Choroidal ganglioneuroma is an extremely rare tumor, with little known regarding its pathogenesis. The present study aimed to investigate the phenotype and genetic alterations in one sporadic patient with rare bilateral choroidal ganglioneuroma.Methods: A 6-year-old boy with histological diagnosis of bilateral ganglioneuroma was recruited in this study. Comprehensive ophthalmic examinations were performed in the patient. Genomic DNA was extracted from peripheral blood collected from the patient, the patient's unaffected family members, and from 200 unrelated control subjects from the same population. Whole exome sequencing was carried out and raw reads were aligned to the human genome reference (hg19) using the Burrows Wheeler Aligner. All available family members were subjected to Sanger sequencing for segregation analysis.Results: Bilateral and extensive retinal detachments were observed in OCT. The diffuse thickening of choroid was identified in B scan and MRI. Genetic analysis revealed the presence of a novel heterozygous PTEN frameshift mutation, c.498delA (p.Thr167LeufsTer16), in exon 6. It was identified in the affected individual, but not in any of the unaffected family members. Genetic analysis showed that there was no mutant in neurofibromatosis-related genes. There were no obvious abnormalities in other organs in comprehensive systemic examinations. Conclusions: A novel de novo PTEN mutation was identified in a bilateral choroidal ganglioneuroma case. Although PTEN mutation has been considered to induces multiple abnormalities, choroidal ganglioneuroma can be the first manifestation without abnormalities in other organs. Further studies are needed to confirm this new association between choroidal ganglioneuroma and the PTEN mutation.