Is Abetalipoproteinemia hereditary?

Abetalipoproteinemia is a strictly hereditary condition caused by mutations in the MTTP gene, which prevents the body from properly absorbing dietary fats and fat-soluble vitamins. It follows an autosomal recessive inheritance pattern, meaning an individual must inherit two copies of the mutated gene—one from each parent—to manifest the disease.

Is Abetalipoproteinemia hereditary?

Yes, Abetalipoproteinemia is a genetic disorder that is strictly hereditary. It is not caused by environmental factors or spontaneous de novo mutations; rather, it is passed down through families. Because it is an autosomal recessive condition, parents of an affected child are typically asymptomatic carriers who each carry one mutated copy of the MTTP gene.

What is the risk of inheritance for families?

When both parents are carriers of the Abetalipoproteinemia mutation, the statistical risk for each pregnancy is as follows:

• 25% chance the child will have Abetalipoproteinemia.


• 50% chance the child will be an asymptomatic carrier.


• 25% chance the child will not have the mutation and will not be a carrier.

How is genetic testing used for diagnosis and family planning?

Genetic testing via molecular analysis of the MTTP gene is the gold standard for confirming a diagnosis of Abetalipoproteinemia. For families with a known history of the condition, genetic counseling is strongly recommended before pregnancy. Genetic counselors can facilitate carrier testing for extended family members and discuss reproductive options, such as preimplantation genetic testing (PGT) or prenatal diagnosis, to help families make informed decisions regarding their reproductive health.

Are de novo mutations common in this condition?

De novo (spontaneous) mutations are extremely rare in Abetalipoproteinemia. In the overwhelming majority of cases, the condition is inherited from parents who are both carriers. If you or a family member have been diagnosed with Abetalipoproteinemia, it is essential to consult with a medical geneticist to review your family pedigree and understand the recurrence risks for siblings or future children.

Next steps

• Consult with a clinical geneticist to confirm your diagnosis through MTTP gene sequencing.


• Connect with the 19 members of our DiseaseMaps.org community to share experiences and coping strategies.


• Request a referral to a genetic counselor to discuss family planning and carrier testing for relatives.

Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Abetalipoproteinemia.


• Online Mendelian Inheritance in Man (OMIM): Entry #200100 (Abetalipoproteinemia).


• Orphanet: Rare disease database entry for Abetalipoproteinemia (ORPHA:10).