Abetalipoproteinemia

The abetalipoproteinemia, also called homozygous familial hypobetalipoproteinemia, describes a severe form of the hypobetalipoproteinemia and is characterized by a persistently low apolipoprotein B and LDL cholesterol level, malabsorption, hepatomegaly and growth delays, as well as neurological and neuromuscular tumors. 

The disease manifests in the first years of life or early childhood. Other symptoms associated with abetalipoproteinemia include steatosis, diarrhea, steatorrhea, and fat malabsorption, atypical retinitis pigmentosa, spastic ataxia, significant cytolysis, acanthocytosis, low levels of fatsoluble vitamins (A, E, K) and possibly even liver cirrhosis.

The causes are mutations in the MTTP gene at the locus 4q22-q24, which encodes the microsomal triglyceride transfer protein MTP. The inheritance is autosomal recessive.

Patients' life expectancy is significantly reduced.