1. Retinoblastoma in twins: Risk assessment of genotypic variants
- Author
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Hansell Soto, Meghan J DeBenedictis, Arun D. Singh, Jacquelyn M. Davanzo, Randy C. Bowen, and Vishal Raval
- Subjects
Proband ,Oncology ,medicine.medical_specialty ,Genotype ,Retinal Neoplasms ,Concordance ,germline ,Risk Assessment ,Germline ,retinoblastoma ,genetic testing ,03 medical and health sciences ,0302 clinical medicine ,Germline mutation ,Internal medicine ,medicine ,Humans ,Family history ,Germ-Line Mutation ,Genetic testing ,medicine.diagnostic_test ,business.industry ,twins ,RE1-994 ,Zygosity ,Ophthalmology ,030221 ophthalmology & optometry ,Original Article ,mosaic ,Risk assessment ,business ,030217 neurology & neurosurgery - Abstract
Purpose: To describe methods of risk assessment in twins with retinoblastoma (RB). Methods: A case series of four RB probands with a twin sibling. Family status, clinical presentation, and RB1 germline status-based risk assessment were analyzed. Results: Two pairs had a positive family history (unilateral and bilateral RB in one of the parents (#1 and #2, respectively) and two pairs (#3 and #4) were sporadic. One of the familial twins (#1) had a high risk (90%) of manifesting RB in the twin. The other case (#2) with an absent RB1 germline mutation in the twin had a 0% risk of developing RB. Among sporadic cases of twins (#3), genetic testing did not identify a germline mutation (tumor sample unavailable) in the proband which downgraded the risk of germline mutation from 15% to T) could be identified (tumor tissue available) in the proband (# 4). Identical germline mutation (and RB tumor) was also noted in the twin. In each case, there was concordance between the assessed risk and manifestation of RB. Conclusion: Assessment of risk of RB in a twin presents with a unique challenge. Depending upon the genotype variant, the risk of developing RB can vary from 0% to 90%. In addition to family history, clinical manifestation in the proband, zygosity status, and RB1 germline status are critical in formulating risk-appropriate surveillance guidelines.
- Published
- 2021