부산대학교 도서관

Inherited chylomicronemia is a condition in which patients have abnormally high blood levels of certain fats, and develop abdominal pain, pancreatic inflammation, and fatty tumors in childhood. Other disorders related to high fat levels, such as premature atherosclerosis (deposition of fatty plaques on the walls of arteries), often develop in adulthood. Inherited chylomicronemia is usually the result of a genetically transmitted defect in lipoprotein lipase, an enzyme that clears chylomicrons (very small fat particles resulting from digestion) from the circulation, and regulates levels of very low-density lipoproteins (one class of fat-protein complex). Several DNA mutations have been identified that cause lipoprotein lipase deficiency, but consistent mutation patterns have not been found in different families and population subgroups. The current study found a particular mutation in 37 unrelated French Canadians with lipoprotein lipase deficiency. The mutation, which resulted in an abnormal amino acid sequence (leucine was substituted for proline) in the enzyme, was present in 73 percent of the mutant forms of the gene. Its frequency in this group was determined by means of the polymerase chain reaction, a method whereby selected segments of DNA can be amplified (replicated) for analysis. The lipoprotein lipase produced by the mutated gene was unable to catalyze (facilitate) biochemical reactions. Only one mutation of the sort described was found when 34 unrelated patients of non-French Canadian ancestry were similarly examined. French Canadians have the highest reported rate of lipoprotein lipase deficiency in the world, with a carrier rate of 1/40 in some parts of Quebec. A discussion is presented of the ways the aberrant gene might have been introduced into the gene pool in this region. Identification of this mutation will allow more accurate determination of the number of people who are carriers. (Consumer Summary produced by Reliance Medical Information, Inc.)