National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Abetalipoproteinemia


Other Names:
Bassen Kornzweig syndrome; Microsomal triglyceride transfer protein deficiency disease; Microsomal triglyceride transfer protein deficiency; Bassen Kornzweig syndrome; Microsomal triglyceride transfer protein deficiency disease; Microsomal triglyceride transfer protein deficiency; ABL; Abetalipoproteinemia neuropathy; Apolipoprotein B deficiency; Betalipoprotein deficiency disease; Congenital betalipoprotein deficiency syndrome; MTP deficiency; Bassen-Kornzweig disease; Homozygous familial hypobetalipoproteinemia See More
Categories:
This disease is grouped under:
Abetalipoproteinemia is a very rare condition that affects fat and vitamin absorption by the intestines and liver, leading to very low LDL-cholesterol and malnutrition. Early symptoms of this condition include diarrhea, vomiting, and poor growth. Without treatment, later complications may include muscle weakness, poor night and color vision, tremors, and speech difficulties.[1][2]  The long-term outcome can be difficult to predict. Abetalipoproteinemia is diagnosed based on clinical exam, laboratory tests showing abnormally low cholesterol, and confirmed by genetic testing.[3] This condition is caused by genetic variants in the MTTP gene and is inherited in an autosomal recessive pattern.[4] This condition has been treated with a low fat diet and vitamin supplements.[3] Most people with abetalipoproteinemia who are treated do not develop complications.[4][5]
Last updated: 4/7/2020
The signs and symptoms of abetalipoproteinemia usually appear in the first few months of life.[3][4] They can include:
  • inability to absorb fats and some vitamins
  • poor growth in infancy
  • digestive symptoms such as diarrhea and steatorrhea (foul-smelling stools)
  • abnormal, star-shaped red blood cells (acanthocytosis)
Because abetalipoproteinemia is extremely rare, the course of the disease is difficult to predict. This condition is usually diagnosed in infancy due to diarrhea, vomiting and poor growth. Most individuals with this condition are treated with excess vitamins and a special, fat-controlled diet and have few complications. Untreated individuals with abetalipoproteinemia can develop gradual vision loss, muscle weakness, tremors, and slow or slurred speech that gets worse over time.[3][4][5]   
Last updated: 4/7/2020

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing of 14 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Malabsorption
Intestinal malabsorption
0002024
30%-79% of people have these symptoms
Abnormality of retinal pigmentation 0007703
Ataxia 0001251
Muscular hypotonia
Low or weak muscle tone
0001252
Reduced tendon reflexes 0001315
5%-29% of people have these symptoms
Visual impairment
Impaired vision
Loss of eyesight
Poor vision
[ more ] 		0000505
Percent of people who have these symptoms is not available through HPO
Abetalipoproteinemia 0008181
Acanthocytosis 0001927
Autosomal recessive inheritance 0000007
CNS demyelination 0007305
Fat malabsorption 0002630
Peripheral demyelination 0011096
Retinal degeneration
Retina degeneration
0000546
Retinopathy
Noninflammatory retina disease
0000488
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Last updated: 7/1/2020
Abetalipoproteinemia is caused by genetic alterations (mutations) in the MTTP gene.[4]
Last updated: 4/7/2020
Abetalipoproteinemia is inherited in an autosomal recessive manner.[4] All individuals inherit two copies of each gene. Autosomal means the gene is found on one of the numbered chromosomes found in both sexes. Recessive means that both copies of the responsible gene must be altered to have the condition.

People with autosomal recessive conditions inherit one alteration from each of their parents. The parents, who each have one gene alteration, are known as carriers. Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When two carriers of an autosomal recessive condition have children, there is a 25% (1 in 4) chance to have a child with the condition. 
Last updated: 4/7/2020
Abetalipoproteinemia is diagnosed based on clinical exam, symptoms, and laboratory tests showing abnormally low cholesterol. It can be confirmed by genetic testing for alterations in the MTTP gene.[4]
Last updated: 4/7/2020

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Individuals with abetalipoproteinemia have been treated with a low fat diet and large doses of fat-soluble vitamins. Specialists involved in the care of someone with abetalipoproteinemia may include:[1][3]
  • nutritionist
  • gastroenterologist
  • hepatologist
  • ophthalmologist
  • neurologist
Last updated: 4/7/2020
Abetalipoproteinemia is very rare and the exact prevalence is difficult to predict. Approximately 100 cases have been reported in the literature.[4]
Last updated: 4/7/2020

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnoses include metabolic diseases with hepatic overload, with steatosis and/or hepatomegaly, atypical diseases of the central and peripheral nervous system, and secondary causes of hypocholesterolemia (iatrogenic or systemic).
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Abetalipoproteinemia. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Abetalipoproteinemia. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Abetalipoproteinemia. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • How can I reach out to other families who have a child with abetalipoproteinemia? See answer


  1. Burnett JR, Bell DA, Hooper AJ, Hegele RA. Clincal Utility Gene Card for: Abetalipoproteinemia – Update 2014.. Eur J. Hum Genet.. Jun 2015; 23(6):890. https://pubmed.ncbi.nlm.nih.gov/25335492.
  2. Paquette M, Dufour R, Hegele RA, Baass A. A tale of 2 cousins: An atypical and typical case of abetalipoproteinemia. J Clin Lipidol. Jul-Aug 2016; 10(4):1030-1034. https://pubmed.ncbi.nlm.nih.gov/27578136.
  3. Lee J, Hegele RA. Abetalipoproteinemia and homozygous hypobetalipoproteinemia: a framework for diagnosis and management. J Inherit Metab Dis. May 2014; 37(3):333-9. https://pubmed.ncbi.nlm.nih.gov/24288038.
  4. Burnett JR, Hooper AJ, Hegele RA,. Abetalipoproteinemia. GeneReviews. Oct 15, 2018; https://www.ncbi.nlm.nih.gov/books/NBK532447.
  5. Junaid Z, Patel K. Abetalipoproteinemia. StatPearls [Internet] Treasure Island (FL): StatPearls Publishing. 2020 Jan - 2019 Dec 16; https://pubmed.ncbi.nlm.nih.gov/30020727.