The N-terminal domain of the retinoblastoma (Rb) tumor suppressor protein (RbN) harbors in-frame exon deletions in partially penetrant hereditary retinoblastomas and is known to impair cell growth and tumorigenesis.
Germline loss of function mutations in tumor suppressor genes RB1 and LKB1/STK11 are associated with the autosomal dominant cancer predisposing syndromes familial retinoblastoma and Peutz-Jeghers syndrome (PJS), respectively.
In contrast, the relative amounts of hMSH2 or RB1 mRNAs carrying premature termination codons were significantly reduced compared with those of wild-type mRNAs in lymphocytes from carriers of hereditary, nonpolyposis, colorectal cancer and hereditary retinoblastoma.
Frequent constitutional C to T mutations in CGA-arginine codons in the RB1 gene produce premature stop codons in patients with bilateral (hereditary) retinoblastoma.
We further analyzed this parental age factor by measuring the relative risk of age groups and comparing the incidence of sporadic hereditary retinoblastoma in the various parental age groups with the incidence of sporadic hereditary retinoblastoma in the total population.