Clinical variant in three families with unique mutation in RB1 gene

Abstract

Herein, we present a case series encompassing three families characterized by a diverse phenotype and a distinctive genotype. In the first family, the patient exhibited bilateral retinoblastoma, while the elder sibling manifested retinocytoma; both parents displayed no abnormalities. In contrast, the second family featured a mother with bilateral retinoblastoma and the older sister showed retinocytoma. The third family presented cases of retinoblastoma in both the patient and the younger sibling, with the father exhibiting retinocytoma. Genetic analysis uncovered mutations in the blood of the proband, elder sibling, and mother in the first and second families, while the third family exhibited mutations in the father and both offspring. Notably, this series underscores the presence of variable expressivity and penetrance, particularly evident in the first family’s experience with retinoblastoma.