Prenatal genetic diagnosis of retinoblastoma and report of RB1 gene mutation from India.

BACKGROUND: Retinoblastoma is the most common intraocular malignancy of childhood. There is a paucity of genetic testing and prenatal genetic diagnosis from India, which has the highest incidence worldwide. MATERIALS AND METHODS: RB1 gene screening of an 8-month-old female child with bilateral retinoblastoma was accomplished using next generation sequencing. The results were used for prenatal testing in this family. RESULTS: A heterozygous germline mutation (chr13: 48951119delA; c.1281delA) was detected, which resulted in premature termination of a protein product (p.Glu428Argfs*29). Prenatal testing in maternal DNA revealed carrier status of the mother. Further clinical examination in the family members revealed retinocytomas in both eyes of the mother and maternal grandmother. Prenatal genetic testing of the developing fetus showed positivity for the mutation. As the family preferred to continue the pregnancy, serial 3-D ultrasounds were carried out every 2 weeks in the third trimester. Ten days after delivery, small extrafoveal tumors developed in both eyes, which were then treated successfully with transpupillary thermotherapy. CONCLUSION: We report the significance of genetic testing in the early detection and management of retinoblastoma from India.