question: Abetalipoproteinemia: Abetalipoproteinemia is a condition characterized by the inability to fully absorb dietary fats, cholesterol and fat-soluble vitamins. [1] Signs and symptoms appear in the first few months of life and can include failure to thrive; diarrhea; acanthocytosis; and stool abnormalities. Other features develop later in childhood and often impair the function of the nervous system, potentially causing slower intellectual development; poor muscle coordination; progressive ataxia ; and an eye disorder called retinitis pigmentosa. [1] [2] Most of the symptoms are due to defects in the absorption and transport of vitamin E. [2] Abetalipoproteinemia is caused by mutations in the MTTP gene and is inherited in an autosomal recessive manner. [3] Early diagnosis, high-dose vitamin E therapy, and medium-chain fatty acid supplements may slow the progression of the nervous system abnormalities. Long-term outlook is reasonably good for most affected people who are diagnosed early. If left untreated, the condition can result in early death. [2] The signs and symptoms of abetalipoproteinemia usually appear in the first few months of life. They can include: failure to thrive in infancy digestive symptoms such as diarrhea and steatorrhea (foul-smelling stools) abnormal, star-shaped red blood cells (acanthocytosis) nervous system (neurologic) symptoms beginning in childhood such as slower intellectual development; peripheral neuropathy ; poor muscle coordination; ataxia ; and intention tremors eye (ophthalmologic) symptoms such as decreased night and color vision; retinitis pigmentosa in adolescence; and gradual deterioration of vision, often leading to blindness in the fourth decade of life[1][2] The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below. Signs and Symptoms Approximate number of patients (when available) Malabsorption Very frequent Abnormality of movement Frequent Abnormality of retinal pigmentation Frequent Ataxia Frequent Muscular hypotonia Frequent Visual impairment Occasional Abetalipoproteinemia - Acanthocytosis - Autosomal recessive inheritance - CNS demyelination - Fat malabsorption - Peripheral demyelination - Pigmentary retinal degeneration - Retinopathy - View complete list of signs and symptoms... Abetalipoproteinemia is caused by changes ( mutations ) in the MTTP gene . The MTTP gene gives the body instructions to make a protein needed for creating beta-lipoproteins. These lipoproteins are necessary for the body to absorb fats, cholesterol, and fat-soluble vitamins (vitamins A, D, E and K), and for transporting these substances in the blood. Mutations in the MTTP result in a lack of beta-lipoproteins, leading to an inability to absorb and transport these substances. This in turn leads to the nutritional and neurologic problems in affected people. [1] Abetalipoproteinemia is inherited in an  autosomal recessive  manner. [4] This means that to be affected, a person must have a  mutation  in both copies of the responsible  gene  in each cell . Affected people inherit one mutated copy of the gene from each parent, who is referred to as a  carrier . Carriers of an autosomal recessive condition typically do not have any signs or symptoms (they are unaffected). When 2 carriers of an autosomal recessive condition have children, each child has a: 25% (1 in 4) chance to be affected 50% (1 in 2) chance to be an unaffected carrier like each parent 25% chance to be unaffected and not be a carrier The Genetic Testing Registry (GTR) provides information about the genetic tests available for abetalipoproteinemia. 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. Prenatal testing may be available for pregnancies at increased risk if the mutations in the family have been identified. A nutritionist or other qualified medical professional should be consulted for specific dietary instruction in people with abetalipoproteinemia. Treatment involves very large doses of vitamin E, as well as large doses of vitamin supplements containing other fat-soluble vitamins (vitamin A, vitamin D, and vitamin K). Linoleic acid supplements are also recommended. [3] [2] Several diet changes and/or restrictions are also needed to prevent stomach problems. A low-fat diet may help with digestive symptoms; medium chain triglycerides may be used (under supervision of a specialist) as a source of fat in the diet. [3] Management in adults typically focuses on specific complications associated with the disorder, and depends on the signs and symptoms present. Affected people may need consultations with several other types of specialists, including a lipidologist, gastroenterologist , hepatologist , ophthalmologist , and neurologist . [2] The long-term outlook ( prognosis ) is reasonably good for most people who are diagnosed and treated early. [2] However, how well each person does depends on the amount of brain and nervous system problems. [3] Therefore, the prognosis can vary. [5] People with prolonged vitamin deficiency, especially of vitamin E, may develop very limiting ataxia and gait disturbances. Some people may develop retinal degeneration and blindness. [2] The following diseases are related to Abetalipoproteinemia. If you have a question about any of these diseases, you can contact GARD. Familial hypobetalipoproteinemia