[3] 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.

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.

Approximately 30–79% of people with the disease display symptoms related to abnormality of the retinal pigmentation, ataxia, muscular hypotonia or reduced tendon reflexes.

[14] 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.

[15] 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.

[16] MTTP-associated mutations are inherited in an autosomal recessive pattern, which means both copies of the gene must be faulty to produce the disease.

[16] The disease is extremely rare with approximately 100 reported cases worldwide since it was first identified by doctors Bassen and Kornzweig in 1950.

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).

[citation needed] Additional complications of the diseases if not properly treated include blindness, mental deterioration, ataxia, loss of peripheral nerve function.

[18] The initial workup of Abetalipoproteinemia typically consists of stool sampling, a peripheral blood smear, and a fasting lipid panel, though these tests are not confirmatory.

[citation needed] Multiple related disorders present with similar symptoms as abetalipoproteinemia that can provide a useful diagnosis through comparisons.

Vitamin E also helps keep skin and eyes healthy; studies show that many affected males will have vision problems later on in life.

Despite the relatively late diagnosis, the patient married and at the age of 34, gave birth to a full-term healthy infant.

[27] There is also a second clinical study, currently under recruitment, to investigate the consequences of deficiencies in lipophilic nutrients in this disease, such as lutein and carotenes, on retinal macular function.