title: The need to screen all retinoblastoma patients for esterase D activity: detection of submicroscopic chromosome deletions.
abstract: Roughly 5% of all patients with retinoblastoma carry a constitutional chromosome deletion on the long arm of chromosome 13, which confers a prezygotic predisposition to tumour development. As offspring of deletion carriers have a 50% risk of inheriting the predisposition locus it is important to identify deletion carriers. The site of the esterase D gene to the often deleted region offers an objective means of deletion identification. The chromosomes of a patient with unilateral retinoblastoma, previously supposed to have a normal karyotype, were reexamined after the discovery that his red blood cells contained reduced activities of esterase D. A small sub-band deletion was found in chromosome region 13q14. These findings emphasise the importance of measurements of esterase D in all patients with retinoblastoma, even those with an apparently normal karyotype.
mesh_terms: D043182:Carboxylesterase; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002872:Chromosome Deletion; D002882:Chromosomes, Human, Pair 13; D005134:Eye Neoplasms / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D007223:Infant; D007621:Karyotyping; D008297:Male; D012175:Retinoblastoma / Q000201:enzymology / Q000235:genetics*
chemical_list: D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase; C020118:ESD protein, human