Retinoblastoma: A Diagnostic Model for India


Purpose: Molecular genetic diagnostics for retinoblastoma are prerequisite for accurate risk prediction and effectivemanagement. Developing a retinoblastoma diagnostic model to establish a flow for laboratory tests is thus a necessityfor tertiary ophthalmic institutions. An efficient diagnostic model could reduce the overall health care costs, redirectthe resources to the high risk group and also avoid unnecessary worry forfamilies. To the best of our knowledge therehas hitherto been no comprehensive diagnostic model for retinoblastoma implemented in any institution in India.Methods and Discussion: The diagnostic model demonstrates the logical and practical flow of various genetics testslike karyotyping, loss of heterozygosity analysis, molecular deletion, linkage analysis (familial cases), mutationscreening of - CGA exons first and then non-CGA exons, methylation screening of RB1 and essential promoterregions screening in a laboratory.
Conclusions: The diagnostic model proposed offers acomprehensive methodologyto identify the causative two-hits for retinoblastomas that could be used while genetic counseling families. Thismodel is applicable in tertiary hospitals in India and neighboring countries, which have the highest incidence ofretinoblastoma and fertility rates in the world. We suggest that this diagnostic model could also be applied withmodification for other cancers.