Lipoprotein lipase deficiency is a disorder that inhibits a person's ability to properly break down fats. This condition is also known as type 1 hyperlipoproteinemia, chylomicronemia, or familial lipoprotein lipase deficiency. Patients with this disease have elevated levels of a type of fat called triglycerides in their blood, and suffer from symptoms such as abdominal pain. After being diagnosed with this disorder, typically on the basis of measuring the activity of lipoprotein lipase in the blood, patients are started on a low fat diet.
Patients with lipoprotein lipase deficiency have a decreased activity of the protein lipoprotein lipase (LPL), which is a chemical that usually helps to break down triglycerides so that they can be transported into the cells of the body. A number of different genetic mutations causing the syndrome have been identified. An abnormality in the deoxyribonucleic acid (DNA) encoding for LPL can cause the disorder, as can a mutation in apoprotein C-II, a protein that normally helps to activate the LPL. The disease is often transmitted in an autosomal recessive fashion, meaning that patients need to inherit mutated genes from both parents in order to develop the condition.
The lack of properly functioning lipoprotein lipase enzyme means that the cells of affected patients are not able to take up fats from the blood. As a result, patients with this disorder have extremely elevated levels of triglycerides in their bloodstream. These high levels of fats can cause a number of symptoms including abdominal pain, skin lesions called xanthomata that represent subcutaneous accumulation of fats, and recurrent problems with inflammation of the pancreas, a condition known as pancreatitis. In the long term, they have an increased risk for heart disease and are often monitored by physicians who specialize in cardiology.
Diagnosis of lipoprotein lipase deficiency is often made by checking a patient's blood for LPL activity. In other patients, diagnosis is based on clinical suspicion, as patients will have very high levels of triglycerides in their blood from a young age, and also often suffer from a number of symptoms. Once one person has been diagnosed with this condition, other family members are typically advised to check their fasting triglyceride blood concentrations to see if they also have elevated levels.
The mainstay of treatment for patients with lipoprotein lipase deficiency is for them to maintain a very low fat diet, with many experts recommending a daily consumption of fewer than 20 grams of fat. The patient's triglyceride levels are checked routinely to ensure that levels do not go too high, as high concentrations can set off an attack of pancreatitis. Patients are also advised to avoid consuming substances that could trigger an elevation in triglyceride levels, including estrogen-containing medications and alcohol.