Parental age in Indian patients with sporadic hereditary retinoblastoma

There is a consistent correlation between sporadic hereditary retinoblastoma and parental age. It has been proven beyond doubt that the birth rank is correlated with parental age. In the present study, a test for the effect of birth rank was performed in order to assess the risk of developing retinoblastoma with increased parental age. The study of the effect of birth rank showed a significant association between sporadic retinoblastoma (bilateral and unilateral) and late para, indicating that fresh germline mutations must have taken place in some of the sporadic cases. An investigation of the effect of birth rank on familial cases, obtained from published papers and our own series, showed that familial retinoblastoma is significantly associated with early para, suggesting early parental age. Further analysis of the mean paternal and maternal ages of sporadic cases (bilateral and unilateral) showed that the mean paternal age of sporadic bilateral (sporadic hereditary) cases was higher than that of sporadic unilateral cases (p<0.05). No such correlation was seen with mean maternal age. Thus, the present study shows that a high paternal age may be associated with sporadic bilateral (sporadic hereditary) retinoblastoma.