THE HORMONE-SENSITIVE LIPASE (LIPE) GENE LOCATED ON CHROMOSOME 19Q13.1-]13.2 IS NOT DUPLICATED ON 19P13.3

The existence of a DNA polymorphism at the hormone-sensitive lipase lo cus could be of great interest for genetic analysis of obesity and rel ated disorders since hormone-sensitive lipase is the rate-limiting enz yme of adipose tissue lipolysis and therefore plays a key role in ener gy metabolism. The polymorphic dinucleotide repeat D19S120 was identif ied within a human genomic clone selected with a rat hormone-sensitive lipase cDNA, This marker was subsequently localized to the short arm of chromosome 19 (p13.3) whereas human hormone-sensitive lipase (LIFE) had been mapped to the long arm of chromosome 19 (q13.1 --> 13.2). A duplication of the hormone-sensitive lipase gene or the presence of a pseudogene could explain the discrepancy, Cosmids from the two regions were analyzed in Southern blot experiments, A human adipose tissue ho rmone-sensitive lipase full-length cDNA probe hybridized only to cosmi ds from the 19q13.1 --> 13.2 region whereas the D19S120 amplicon probe hybridized only to cosmids from the p13.3 region, These data show tha t the occurrence of gene duplication or the presence of a pseudogene o n the short arm of chromosome 19 is very unlikely and that D19S120 is unrelated to the hormone-sensitive lipase gene.