ABSTRACT
Background
Retinoblastoma (RB) is an intraocular childhood cancer develops due to inactivation of RB1 gene. Identification of RB1 genetic variants, correlating and confirming genetic test results with clinical outcomes are crucial for effective RB management.
Methods
Retrospective study of 62 RB patients and 14 family members who underwent genetic testing either by next generation sequencing (NGS) or multiplex ligation-dependent probe amplification (MLPA) or by both for screening RB1 germline mutations present in peripheral blood. Mutational outcomes were correlated with clinical outcomes evaluated over a follow-up period of 12 months.
Results
Of the 62 patients, 35 (56%) had bilateral RB and 27 (44%) had unilateral RB. Out of 24 (52%) variants detected by NGS, 9 (37.5%) were novel and 15 (62.5%) were known in 46 probands. Six (18%) gross deletions were detected by MLPA in 34 probands. The mutation detection rate by NGS and MLPA in unilateral cases was 15% (n = 4) and 74% (n = 26) in bilateral cases. In patients with RB1 genetic mutations versus those without, the rate of primary enucleation (7 (12%) vs 18 (44%) eyes; p = .0008) was inversely proportional to tumor recurrence (25 (45%) vs 6 (15%) eyes; p = .002). There was no difference in the rate of globe salvage and metastasis, over a mean follow-up period of 12 months.
Conclusion
The mutations screening is important for risk assessment in future siblings and offspring of RB patients and most important in unilateral RB for determining if hereditary or not hereditary RB. Its role in predicting clinical outcomes is yet to be determined.
Acknowledgments
The authors acknowledge the funding support from the Operation Eyesight Universal Institute for Eye cancer (SK) and Hyderabad Eye Research Foundation (SK), LV Prasad Eye Institute, Hyderabad, India
Disclosure statement
No potential conflict of interest was reported by the author(s).
Ethics approval statement
The study was conducted according to the guidelines of the Declaration of Helsinki, and was approved by the Institutional Review Board of L V Prasad Eye Institute, Hyderabad, India − 500 034 (IRB approval no. LEC-BHR-01-20-390)
Authors contribution
The study was conceptualized by SK and RM. Data was collected and analyzed by RM, AP, GR. The manuscript is drafted by RM, AP, and SK. All the authors reviewed the manuscript and contributed with critical inputs to the final draft.