Familial LCAT deficiency is one of two types of LCAT deficiency; the other type of LCAT deficiency is fish-eye disease. Both types of LCAT deficiency are caused by mutations in the LCAT gene and are inherited in an autosomal recessive manner. Although there is no specific treatment or cure for familial LCAT deficiency, there may be ways to manage the symptoms. A team of doctors is often needed to figure out the treatment options for each person.

The earliest symptom of familial LCAT deficiency, typically occurring in childhood, is cloudiness in the front surface of the eye (cornea), known as corneal opacities. Kidney disease, sometimes leading to kidney failure, usually begins in adolescence or early adulthood. Other symptoms often found in individuals with LCAT deficiency include:

• Hemolytic anemia (shortage of red blood cells)
• Enlargement of the liver (hepatomegaly), spleen (splenomegaly), or lymph nodes (lymphadenopathy)
• Accumulation of fatty deposits in the artery walls (atherosclerosis)
• Swelling of the optic nerve (papilledema)
• A buildup of fat under the surface of the skin (xanthelasma)
• Symptoms of kidney failure, such as high blood pressure

LCAT gene. The LCAT gene provides instructions for making an enzyme (protein) called lecithin-cholesterol acyltransferase (LCAT). This enzyme is involved in removing cholesterol from the blood and tissues by helping it attach to a group of proteins, called lipoproteins. The cholesterol is then transported to the liver and sent to other tissues in the body or removed from the body.

The LCAT enzyme has two major functions: alpha and beta LCAT activity. Alpha-LCAT activity helps attach cholesterol to a lipoprotein called high-density lipoprotein (HDL), while beta-LCAT activity helps attach cholesterol to other lipoproteins called low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL).

In familial LCAT deficiency, LCAT gene mutations either prevent the production of the LCAT enzyme or impair both the alpha-LCAT and beta-LCAT activity, reducing the enzyme's ability to attach cholesterol to lipoproteins. This is known as a complete LCAT deficiency. This likely leads to a buildup (deposit) of cholesterol in tissues throughout the body, including the corneas and kidneys.

The long-term outlook (prognosis) for people with familial LCAT deficiency varies depending on the severity of associated signs and symptoms. The most serious complication of familial LCAT deficiency is kidney failure.