[Familial LCAT deficiency].
Familial deficiency of lecithin-cholesterol acyltransferase (LCAT) was described by Norum and Gjone in 1967. LCAT (EC 2.3.1.43) is a serum enzyme involved in reverse cholesterol transport. LCAT deficiency is associated with percentage increase of free cholesterol and decrease of esterified cholesterol, and disturbances in lipoprotein particles structure, because cholesterol esters form the lipoprotein core. Lipid disorders involve also other organs, such as kidneys, cornea and erythrocytes; with clinical manifestations of proteinuria, usually associated with renal insufficiency, corneal opacities and haemolytic anemia. Gene encoding LCAT is localized in region q 21-22 on chromosome 16. It consists of 6 exons, divided by 5 introns and spans 4.2 bp. Familial LCAT deficiency is an autosomal recessive disorder. In LCAT deficient patients several mutations in all 6 exons have been described. Clinical manifestations of familial LCAT deficiency are highly variable, although no or only low LCAT activity is present and this may suggests that expression of the disease is modulated by additional environmental factors and genes of minor importance.