Familial LCAT Deficiency (Lecithin-Cholesterol Acyltransferase Deficiency)
What is Familial LCAT Deficiency (Lecithin-Cholesterol Acyltransferase Deficiency)?
Familial LCAT deficiency is a rare genetic disorder that affects how your body processes cholesterol. LCAT stands for lecithin-cholesterol acyltransferase, an enzyme that helps convert free cholesterol into a form your body can use and store. When this enzyme does not work properly, cholesterol builds up in the wrong places.
This condition disrupts the production of HDL cholesterol, often called good cholesterol. HDL normally carries excess cholesterol from your tissues back to your liver for removal. Without enough working LCAT enzyme, HDL particles cannot mature properly. This leads to very low levels of HDL and abnormal cholesterol deposits throughout your body.
The condition is inherited in an autosomal recessive pattern. This means you need to receive a faulty gene from both parents to develop the disorder. Symptoms typically appear in childhood or early adulthood. The condition can affect multiple organs including your eyes, kidneys, and blood cells.
Symptoms
- Cloudy or hazy corneas, causing vision problems
- Anemia or low red blood cell count
- Protein in the urine
- Kidney problems or declining kidney function
- Enlarged spleen or liver
- Abnormal lipid deposits in tissues
- Fatigue and weakness
- High triglyceride levels
Many people with familial LCAT deficiency have no symptoms in early childhood. The corneal clouding is often the first visible sign, appearing as a grayish haze in the eyes. Kidney problems may develop gradually over years. Some individuals only discover they have the condition during routine blood work or eye exams.
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Causes and risk factors
Familial LCAT deficiency is caused by mutations in the LCAT gene. This gene provides instructions for making the LCAT enzyme, which plays a key role in cholesterol processing. When both copies of the gene are faulty, the enzyme cannot function properly. The LCAT enzyme normally works with Apolipoprotein A1, or Apo A1, to help mature HDL particles. Without functional LCAT, cholesterol accumulates in abnormal forms throughout the body.
Because this is a genetic condition, you cannot develop it from lifestyle factors. The only risk factor is having two parents who each carry one copy of the mutated gene. Children of two carriers have a 25% chance of inheriting both faulty genes and developing the condition. Genetic counseling can help families understand their risk. There is no way to prevent the condition if you inherit the genes.
How it's diagnosed
Doctors diagnose familial LCAT deficiency through blood tests and genetic testing. Blood work typically shows very low HDL cholesterol and low Apolipoprotein A1 levels. Apo A1 is a protein that makes up most of HDL cholesterol particles. Measuring Apo A1 helps identify the abnormal HDL metabolism seen in this condition. You may also have high triglycerides and abnormal cholesterol ratios.
Rite Aid offers Apolipoprotein A1 testing as an add-on to our flagship blood panel. This test can help identify the low Apo A1 levels associated with LCAT deficiency. Genetic testing confirms the diagnosis by identifying mutations in the LCAT gene. Your doctor may also examine your eyes for corneal clouding and order kidney function tests. Early diagnosis helps monitor organ function and plan appropriate care.
Treatment options
- Regular monitoring of kidney function with blood and urine tests
- Eye exams to track corneal clouding and vision changes
- Management of anemia with iron supplements or other treatments
- Low-fat diet to help manage triglyceride levels
- Medications to control high triglycerides when needed
- Dialysis or kidney transplant for advanced kidney disease
- Corneal transplant for severe vision problems
- Regular follow-up with specialists including nephrologists and ophthalmologists
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- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Both conditions involve mutations in the LCAT gene, but they differ in severity. Familial LCAT deficiency is the complete form where the enzyme has little to no activity. Fish eye disease is a partial deficiency where some enzyme activity remains. Fish eye disease mainly affects the eyes with corneal clouding, while familial LCAT deficiency also causes kidney disease and anemia.
Familial LCAT deficiency is extremely rare. Fewer than 100 cases have been reported worldwide since the condition was first described. The exact prevalence is unknown because many cases may go undiagnosed. Certain populations with higher rates of consanguinity, or marriage between relatives, may have slightly higher rates.
There is currently no cure for familial LCAT deficiency. Treatment focuses on managing symptoms and preventing complications. Researchers are studying enzyme replacement therapy and gene therapy as potential future treatments. For now, regular monitoring and supportive care remain the standard approach.
If you have familial LCAT deficiency, your children will inherit at least one faulty gene copy. Whether they develop the condition depends on the other parent. If your partner carries one faulty gene, each child has a 50% chance of having the condition. If your partner has two normal genes, your children will be carriers but will not develop symptoms.
The LCAT enzyme is essential for maturing HDL cholesterol particles. Without working LCAT, your body cannot convert free cholesterol into the stored form found in mature HDL. The HDL particles remain small, unstable, and quickly removed from your bloodstream. This results in very low HDL levels on blood tests.
The relationship between familial LCAT deficiency and heart disease is complex. Despite very low HDL cholesterol, people with this condition do not always have increased heart disease. Some studies suggest normal or even reduced risk. The condition does cause other serious problems like kidney disease that require careful management.
Corneal clouding appears as a grayish or whitish haze on the normally clear surface of the eye. It often starts at the edges of the cornea and spreads toward the center over time. The clouding is caused by cholesterol deposits in the corneal tissue. Vision may become progressively blurry as the clouding worsens.
Most doctors recommend blood testing every 3 to 6 months for kidney function monitoring. Your Apolipoprotein A1 and lipid levels should be checked regularly to track the condition. Your doctor will determine the right schedule based on your symptoms and organ function. More frequent testing may be needed if kidney disease progresses.
Diet changes cannot fix the underlying enzyme deficiency, but they can help manage some symptoms. A low-fat diet may help reduce triglyceride levels, which are often elevated in this condition. Some people benefit from limiting saturated fats and eating more plant-based foods. Work with a nutritionist familiar with lipid disorders to create a personalized eating plan.
Kidney disease is one of the most serious complications of familial LCAT deficiency. Abnormal cholesterol deposits accumulate in kidney tissues, damaging the filtering structures over time. This leads to protein leaking into the urine and declining kidney function. Some people eventually need dialysis or kidney transplant. Regular monitoring helps catch kidney problems early.