These lipoproteins are both necessary for the absorption of fats, cholesterol, and fat-soluble vitamins from the diet and necessary for the efficient transport of these substances in the bloodstream. Most of the mutations in this gene lead to the production of an abnormally short microsomal triglyceride transfer protein, which prevents the normal creation of beta-lipoproteins in the body. MTTP-associated mutations are inherited in an autosomal recessive pattern, which means both copies of the gene must be faulty to produce the disease.The disease is extremely rare with approximately 100 reported cases worldwide since it was first identified by doctors Bassen and Kornzweig in 1950. Mechanism
Abetalipoproteinemia effects multiple physiological systems, the two most common being the nervous and the skeletal. Disruption of nervous function includes loss of reflexes, speech impairments, tremors or involuntary motor tics, or peripheral neuropathy (damage to the nerves outside of the brain and spinal cord). Peripheral neuropathy causes loss of sensation, weakness or numbness and pain in the extremities through stabbing, burning, or tingling sensations. Skeletal system developments often include lordosis, kyphoscoliosis, or pes cavus. Individuals often have abnormal bleeding due to the difficulty of forming clots.Additional complications of the diseases if not properly treated include blindness, mental deterioration, ataxia, loss of peripheral nerve function. Diagnosis
The initial workup of Abetalipoproteinemia typically consists of stool sampling, a blood smear, and a fasting lipid panel, though these tests are not confirmatory. As the disease is rare, though a genetics test is necessary for diagnosis, it is generally not done initially.
Abetalipoproteinemia (also known as: Bassen-Kornzweig syndrome, microsomal triglyceride transfer protein deficiency disease, MTP deficiency, and betalipoprotein deficiency syndrome) is a disorder that interferes with the normal absorption of fat and fat-soluble vitamins from food. It is caused by a mutation in microsomal triglyceride transfer protein resulting in deficiencies in the apolipoproteins B-48 and B-100, which are used in the synthesis and exportation of chylomicrons and VLDL respectively. It is not to be confused with familial dysbetalipoproteinemia.It is a rare autosomal recessive disorder. Presentation
Symptoms
Often symptoms will arise that indicate the body is not absorbing or making the lipoproteins that it needs. These symptoms usually appear en masse.These symptoms come as follows:

Failure to thrive (i.e. failure to grow in infancy)
Steatorrhea (i.e. fatty, pale stools)
Frothy stools
Foul smelling stools
Protruding abdomen
Intellectual disability/developmental delay
Developmental coordination disorder, evident by age ten
Ataxia
Muscle weakness
Slurred speech (dysarthria)
Scoliosis (curvature of the spine)
Progressive decreased vision
Balance and coordination problems

Signs
Acanthocytosis
Retinitis pigmentosa
Low blood cholesterol

Features
Abetalipoproteinemia affects the absorption of dietary fats, cholesterol, and certain vitamins. People affected by this disorder are not able to make certain lipoproteins, which are molecules that consist of proteins combined with cholesterol and particular fats called triglycerides. This leads to a multiple vitamin deficiency, affecting the fat-soluble vitamin A, vitamin D, vitamin E, and vitamin K. However, many of the observed effects are due to vitamin E deficiency in particular. Signs and symptoms vary and present differently from person to person. In general, 80–99% of individuals exhibit malabsorption of fats and fat-soluble vitamins.