Incidence of 13q deletion among 50 patients with retinoblastoma in Indian population

1. Cytogenetic analysis using lymphocytes of 50 patients with Rb in Indian population has been made. A late mean age at diagnosis, 3 (6%) sporadic patients with constitutional chromosomal deletion of 13q14 and midface dysmorphism in a few patients has been recorded and analyzed. 2. All the three patients showed a mosaic karyotype of 46XY/46XY del (13q14.1->q14.3) of whom two with bilateral and one with unilateral Rb. The Rb patients with deletion didn't differ significantly and is within the range (5%-10%) compared with other cytogenetic surveys done in the other parts of the world. None of the family members showed any chromosomal abnormality. 3. The need for genetic counseling and cytogenetic analysis in patients with Rb is stressed.