Abetalipoproteinemia, also known as Bassen-Kornzweig syndrome, is a condition where the organs of the body are unable to absorb fats, fat-soluble vitamins (like E, A, D, and K), and cholesterol from the diet. An individual with the condition does not have a specific kind of lipoprotein called a beta-lipoprotein which aids with the absorption process. Certain amounts of fats, vitamins, and cholesterol are important for healthy development and growth – without them developmental problems will occur.
People who have inherited abetalipoproteinemia have noticeable symptoms when they are only a few months old. Symptoms can include the inability to put on weight; diarrhea; fatty, frothy, rank-smelling stools; a bloated abdomen; and oddly-shaped red blood cells. As these individuals age, there may be problems with their nervous system, muscle coordination troubles, slurred speech, curvature of the spine, poor vision, and difficulties with movement and balance. Many of the symptoms of abetalipoproteinemia are the result of the lack of absorption of vitamins, particularly vitamin E.
There are very few reported cases of abetalipoproteinemia. It is an autosomal recessive genetic disorder where mutations affect the microsomal triglyceride transfer protein (MTTP) gene. This means that a person affected with abetalipoproteinemia has parents that each have one copy of the mutated MTTP gene. So, the parents do not have any symptoms that they are carriers of the disorder, but the children do.
There are some tests that can help determine whether an individual has abetalipoproteinemia. Apolipoprotein B blood test will determine the lipid levels. In addition, other blood tests can check to see if there are any fat-soluble vitamin deficiencies. A stool sample analysis, cholesterol test, and eye exam may also be performed. Treatment includes the use vitamin and linoleic acid supplements and limited fat and long-chain triglyceride intake.
Genetic testing of abetalipoproteinemia may be available, so prevention of deterioration is possible. In those cases, high quantities of fat-soluble vitamins may decrease the progression, particularly for vision-related problems. Plus, when supplements are taken, the prognosis is good. However, in its most severe form, some affected individuals may suffer from irreversible damage to their nervous system before they reach the age of 30. Complications can include blindness, damage to nerves, and deterioration of the individual’s mental ability.
Although it is rare, there is increasing interest in the disorder. The Abetalipoproteinemia Collaboration Foundation began in January 2007. Its goal is to globally link and set up an international support group for those affected with abetalipoproteinemia, their families, doctors, and scientists.