Abetalipoproteinemia is an inherited metabolic disorder characterized by impaired absorption of fats and certain vitamins from the diet.
Many of the signs and symptoms of abetalipoproteinemia result from a severe deficiency of fat-soluble vitamins including vitamins A, E and K. The first signs typically appear in infancy, and include failure to thrive, diarrhea, and fatty, foul-smelling stools. Additionally, more signs and symptoms appear as the affected individual ages and include disturbances in nerve function that may lead to poor muscle coordination and difficulty with balance and movement. Anemia, or low number of red blood cells, along with abnormally star-shaped red blood cells (acanthocytosis) is another common symptom of abetalipoproteinemia. There is no cure for this disorder, and treatment is directed towards the specific symptoms that are apparent, including dietary changes to reduce the intake of long-chain saturated fatty acids.
This condition is caused by pathogenic (disease-causing) variants in the MTTP gene. Abetalipoproteinemia exhibits autosomal recessive inheritance, meaning both parents must be carriers to have a 25% chance of having a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a carrier frequency of 1 in 131. Carriers do not typically show any signs or symptoms of the condition. Another name for this condition is Bassen-Kornzweig syndrome.