Dr. PREMA K.V. SUBRAMANIAM

DR. PARAG K. SHAH, DR. NARENDRAN V.

Abstract

Case series of three families to show the peculiarity of RB1 mutation, Retinoblastoma expression and penetrance.The first family, patient was a Boy 15 months old diagnosed to have Bilateral Retinoblastoma, On screening the elder sibling had Bilateral Retinocytoma. Parents were normal. Second Family,patient 6 months old had Bilateral Retinoblastoma, Elder sibling 5 year old had Retinocytoma , mother’s eyes were enucleated. Third family,Father had Retinocytoma and patient and younger sibling had Retinoblastoma. Genetic analysis performed.In the First and second family there was heterozygous frameshift mutation in different Exons in the blood of proband, elder sibling and the Mother. Third family heterozygous deletion of whole RB1 gene in blood of the Father and two offsprings was noted. Inspite of the presence of same mutant gene there is variable expression of disease in same generation, Additional genetic workup will clear the mystery.