Abetalipoproteinemia

Abetalipoproteinemia is a rare inherited disorder that causes the body to be unable to properly absorb and digest fats. As a result, people with abetalipoproteinemia often have severe deficiencies of vitamins A, D, E, and K.

Abetalipoproteinemia is also known as Bassen-Kornzweig syndrome. This condition, which causes the body to be unable to absorb fat, can cause a variety of symptoms, from diarrhea with oily stools to delayed growth and development.

The exact number of people with abetalipoproteinemia is unknown. However, it is thought to occur in 1 in 1,000,000 people in the general population.

Causes of Abetalipoproteinemia

Abetalipoproteinemia is caused by changes (mutations) in the MTTP gene. This gene functions to form beta lipoprotein, a substance that carries fat from food to be absorbed by the intestines and processed in the liver.

MTTP gene mutations cause the formation of beta lipoproteins to be reduced or absent altogether. Lack of beta lipoproteins makes it difficult for the body to absorb fats and fat-soluble vitamins, so that people with abetalipoproteinemia experience malnutrition.

Risk factors for abetalipoproteinemia

Abetalipoproteinemia is a genetic disorder that can be inherited from parents . Abetalipoproteinemia is autosomal recessive . This means that the risk of a child getting the disease is around 25% if both parents have the MTTP gene mutation.

Children of both parents who have the MTTP gene mutation also have a 50% chance of not experiencing abetalipoproteinemia, but of being carriers of the gene .

Symptoms of Abetalipoproteinemia

Abetalipoproteinemia can cause symptoms in various parts of the body, from the digestive tract, nerves, to the eyes. Some of the symptoms are:

• Diarrhea with fatty, pale, frothy, and very foul-smelling stools
• Nausea and vomiting
• Belly bulging
• Disorders of balance and coordination of body movements
• Hunchback spine
• Developmental delay
• Visual disturbances that worsen over time, due to impaired development of the retina
• Ataxia
• Difficulty speaking
• Tremors and tics
• Muscle weakness
• Tingling and numbness
• Rapid and repetitive movements of the eyes ( nystagmus )
• Pale, often weak, dizzy, and often faint

When to see a doctor

Take your child to the doctor if he/she experiences the above symptoms. Early examination is necessary to prevent complications.

Genetic testing should also be performed on couples who are planning a pregnancy, especially if they have a family history of abetalipoproteinemia.

Diagnosis Abetalipoproteinemia

To diagnose abetalipoproteinemia, the doctor will ask about the symptoms the patient is experiencing. The doctor will also ask about the patient’s and family’s medical history, especially those related to abetalipoproteinemia.

After that, the doctor will perform physical and neurological tests. The doctor can also perform supporting examinations to confirm the diagnosis, including:

• Complete blood count , to detect blood disorders, such as anemia, thrombocytopenia, or pancytopenia, and to look for the appearance of shriveled and spiky blood cells ( acanthocytes ).
• Lipid profile test, to measure the body’s cholesterol, lipoprotein and triglyceride levels.
• Stool examination , to assess the consistency, color and odor of the stool so that signs of the body not absorbing fat can be seen.
• Eye examination , to see damage to the retina of the eye
• Abdominal ultrasound , to see the condition of the liver
• MRI of the brain or spine, to see damage to the brain and nerves

Treatment of Abetalipoproteinemia

Treatment of abetalipoproteinemia aims to relieve symptoms and prevent complications. Some treatment methods that doctors can do are:

Low saturated fat diet

In most cases, doctors will ask patients to strictly reduce their consumption of foods high in saturated fat. This diet aims to relieve digestive tract disorders, such as diarrhea and vomiting.

In infants, doctors will recommend special formula milk and coconut oil containing medium chain fatty acids . These fats do not require lipoprotein when digested so they can be directly absorbed by the body. However, consumption of these fats must be closely monitored because too much can cause fatty liver.

In addition to the above types of fat, doctors can also prescribe omega 6 supplements.

Administration of vitamin

Supplementation of vitamins A, D, E, and K aims to relieve symptoms and prevent complications. Vitamin E and A supplements can be given to treat nerve and eye disorders.

Meanwhile, vitamin K supplements can improve blood clotting. Vitamin D supplements are given to help bone growth and muscle function.

Changes in diet and consumption of vitamin supplements need to be implemented throughout the patient’s life.

Therapy

In patients who experience nerve disorders, doctors will recommend physiotherapy , speech therapy, or occupational therapy .

It should be noted that treatment should be done as early as possible to avoid complications. Patients will also be asked to have regular check-ups with an ophthalmologist, an internist, and a neurologist. Generally, doctors will ask patients to have check-ups every 6 months.

Complications of Abetalipoproteinemia

If not treated properly, abetalipoproteinemia can cause the following complications:

• Nerve and brain damage
• Muscle weakness
• Anemia
• Disorders of the retina ( retinitis pigmentosa ), night blindness, and even blindness
• Mental retardation

Prevention of Abetalipoproteinemia

Abetalipoproteinemia is a genetic disorder that is difficult to prevent. However, the risk of abetalipoproteinemia can be reduced by consulting and genetic screening before planning a pregnancy.

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