A deleted chromosome no. 13 in human retinoblastoma cells: relevance to tumorigenesis

One hit, two hits, three hits, more? Genomic changes in the development of retinoblastoma

“…The second often-described cytogenetic abnormality seen by karyotype is gain of chromosome arm 1q material, observed in 44% of tumors (Potluri et al, 1986). Other common changes include monosomy of chromosome 16 (18%), gain of 1p (13%), and the occasional presence of homogenously staining regions (HSRs) Chaum et al, 1984) and/or double minutes (DMs) (Balaban-Malenbaum et al, 1981;Mairal et al, 2000). Also observed are loss of a sex chromosome and changes involving chromosomes 17 and 19.…”

Chromosome 20 deletion in human multiple endocrine neoplasia types 2A and 2B: a double-blind study.

“…tardation or other malformations, the tumor cells may have a karyotype abnormality, but the peripheral blood chromosomes of the patient appear normal (10)(11)(12). In two families with autosomal dominant predisposition to renal-cell carcinoma, the affected individuals had either an inherited (13) or a tumor-acquired (14) balanced translocation.…”

Retinoblastoma

“…Using classic deletion mapping, Sparkes and coworkers studied five patients with retinoblastoma and found that, in all five, esterase D activity was only 50% of normal. 19 The current consensus is that there is indeed a single retinoblastoma locus, RB1, that is mutated in all forms of retinoblastoma. 17 Based on the fact that the chromosome 13 deletion and the esterase D locus were tightly linked to retinoblastoma in multiple families with clinically and pathologically indistinguishable disease, Murphree and Benedict argued that there was probably a single RB1 locus.…”