LCATpuutteet

LCATpuutteet refers to a deficiency in the enzyme lecithin-cholesterol acyltransferase (LCAT). LCAT plays a crucial role in the metabolism of cholesterol, particularly in the process of reverse cholesterol transport. This enzyme esterifies cholesterol in high-density lipoproteins (HDL), converting free cholesterol into cholesteryl esters. These cholesteryl esters are then transported from peripheral tissues back to the liver for excretion.

There are two main forms of LCAT deficiency: familial LCAT deficiency (F-LCATD) and fish-eye disease (FED). F-LCATD is a rare autosomal recessive disorder caused by mutations in the LCAT gene, leading to a near-complete absence of LCAT activity. Individuals with F-LCATD typically present with severe corneal opacities, leading to impaired vision, and often develop renal failure due to the accumulation of lipids in the kidneys. They also exhibit very low levels of HDL cholesterol and a distinctive lipid profile in their plasma.

Fish-eye disease is a milder allelic variant also resulting from LCAT gene mutations, but with residual LCAT activity. Patients with FED also have corneal opacities, though typically less severe than in F-LCATD, and show significantly reduced HDL cholesterol levels. However, they generally do not develop the severe renal complications seen in F-LCATD. The primary physiological consequence of LCAT deficiency is the impaired ability to remove excess cholesterol from the body, which can contribute to atherosclerosis and other cardiovascular issues, although the clinical manifestations vary depending on the severity of the enzyme deficit.