Hereditary retinoblastomas develop the following chromosomal deletion -

Ans. is 'a' i.e., 13q14 Deletion of a small number of tightly clustered genes result in a number of genetic disorders termed as microdeletion syndromes. Wilm's tumor - Aniridia complex (WAGR syndrome) Retinoblastoma Prader - Willi,syndrome Angelman syndrome DiGeorge's syndrome Velo-Cardiofacial syndrome llp 13 Pa of (deletion of sho arm of chromosome 11) 13q 14.11 (deletion of pa of long arm of chromosome 13) 15q 11-13 (deletion of pa of long arm of chromosome 15) 22q11(deletion of pa of long arm of chromosome 22) o Deletions involving the long arm of chromosome 22 (22q 1 I ) are the most common microdeletions identified to data. o Velo-cardiofacial syndrome*, is the most commonly associated syndrome.