Disease characteristics. Familial lipoprotein lipase (LPL) deficiency is characterized by increased plasma trigylceride concentration caused by delayed clearance of chylomicrons from the plasma after digestion of dietary fat. Affected individuals have childhood-onset episodic abdominal pain, recurrent acute pancreatitis, eruptive cutaneous xanthomata, and hepatosplenomegaly. Symptoms resolve with restriction of dietary fat to 20 grams/day or less.
Diagnosis/testing. Familial LPL deficiency is caused by very low or absent activity of LPL encoded by the gene LPL. The diagnosis of familial LPL deficiency is based on the assay of LPL activity in plasma following intravenous administration of heparin. Detection of very low or absent LPL activity in an assay system that contains either normal plasma or apoprotein C-II and excludes hepatic lipase is diagnostic of familial LPL deficiency.
Familial lipoprotein lipase deficiency is inherited in an autosomal recessive manner. The sibs of an affected individual have a 25% chance of being affected, a 50% chance of being unaffected and carriers, and a 25% chance of being unaffected and not carriers. Prenatal testing may be available through laboratories offering custom prenatal testing.