Genotype-phenotype correlation analysis in retinoblastoma patients from India

Background: Genetic analysis has a beneficial impact on retinoblastoma management enabling definite risk assessment. However, information regarding genotype-phenotype correlation in retinoblastoma is limited. Aim: To analyze the retinoblastoma susceptibility gene for mutations in retinoblastoma patients and correlate the genotypes the phenotypes. Methodology: Eleven retinoblastoma patients, who underwent molecular genetic studies were classified into high, moderate or low disease severity groups based on phenotype. Results: Seven patients had high disease severity and four moderate disease severity. Eleven truncating mutations were detected; six were in the N-terminus region of the retinoblastoma protein and two in the A/B pocket (p=0.03). Conclusions: No significant association between mutation type and disease severity could be established in the present study. However a positive correlation between location of the mutations in certain domains of the retinoblastoma protein and disease severity was observed. To the best of our knowledge this is the first genotype-phenotype correlation study in retinoblastoma patients from India.