Lecithin cholesterol acyltransferase deficiency

Lecithin cholesterol acyltransferase deficiency (LCAT deficiency) is disorder of lipoprotein metabolism.

Lecithin cholesterol acyltransferase catalyzes the formation of cholesterol esters in lipoproteins.

Types
The disease has two forms:


 * familial LCAT deficiency in which there is complete LCAT deficiency.
 * fish eye disease in which there is a partial deficiency.

Both are autosomal recessive disorders caused by mutations of the LCAT gene located on chromosome 16q22.

Presentation
A deficiency of LCAT causes accumulation of unesterified cholesterol in certain body tissues. Symptoms of the familial form include diffuse corneal opacities, target cell hemolytic anemia and proteinuria with renal failure. Fish eye disease only causes progressive corneal opacification.

Mortility and Morbidity
Renal failure is the major cause of morbidity and mortility in complete LCAT deficiency, while in partial deficiency(bird's eye disease) major cause for morbidity is visual impairement due to corneal opacities. These patients have low HDL Cholesterol but surprisingly premature atherosclerosis is not seen. However, There are some reported cases.

Signs and symptoms
In complete LCAT deficincy patients may present with Anemia, Corneal opacities,Hepatosplenomegaly, renal insufficiency while in partial deficiency (bird's eye disease) corneal opacities is the main finding with hepatosplenomegaly.

Diagnosis
Battery of tests are required such as CBC for anemia, kidney functions, urine for proteinurea, Lipid profile,these patients have very low HDL cholesterol and high triglyceride level,High free cholesterol and low cholesterol esters levels. However definitive diagnosis rest with LCAT gene analysis for mutation and functional activity.