Deletions of proximal 15q and non-classical Prader-Willi syndrome phenotypes.
A deletion of the long arm of chromosome 15 (usually involving bands 15q11-q12) has been seen in approximately 50% of Prader-Willi syndrome (PWS) patients [Ledbetter et al, 1982]. However, 14 patients with non-PWS (or atypical PWS) phenotype with 15q deletion indicate great clinical variability. A deletion was found in a propositus with a de novo translocation [45,XY, -15, -22, +rec(15;22) (22pter----22q13.2::15q14----15qter)], who had anomalies not normally observed in PWS patients. Activities of several enzymes mapped to the involved chromosomes were studied in the patient and control individuals. A 50% decrease in the level of arylsulfatase-A confirmed a small deletion in 22q(22q13.2----qter), and additional studies localized more precisely the loci for alpha-mannosidase (cytoplasmic) and beta-galactosidase.
Schwartz
S
S
Max
S R
SR
Panny
S R
SR
Cohen
M M
MM
D002553:Cerebroside-Sulfatase / Q000235:genetics; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D002901:Chromosomes, Human, 13-15; D002904:Chromosomes, Human, 21-22 and Y; D005347:Fibroblasts / Q000648:ultrastructure; D006801:Humans; D007231:Infant, Newborn; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D008361:Mannosidases / Q000235:genetics; D010641:Phenotype; D011218:Prader-Willi Syndrome / Q000201:enzymology / Q000235:genetics*; D014178:Translocation, Genetic; D043323:alpha-Mannosidase; D001616:beta-Galactosidase / Q000235:genetics
D002553:Cerebroside-Sulfatase; D008361:Mannosidases; D001616:beta-Galactosidase; D043323:alpha-Mannosidase