What is Abetalipoproteinemia?
This is a medical disorder that affects how fats are made and used in your body. It is a rare inherited disorder. It is also known as Bassen-Kornzweig syndrome. Your body needs fats for healthy muscles, digestion, and nerves. Just like water and oil, these fats cannot travel in your blood around your body by themselves because they just do not mix in. Instead they have to attach themselves to special protein cells called lipoproteins in order to go where they are needed in your body via your blood.
When someone has abetalipoproteinemia it is apparent in infancy. It affects boys more than girls. The average percentage of boys to girls is seventy percent to thirty percent. Although it is an inherited disorder it is also autosomal recessive, which means that both of the parents have to have this faulty gene in order to pass it down to the children. Sometimes the parents do not have any symptoms because they are carriers of the mutated MTTP gene. There are approximately one hundred cases of abetalipoproteinemia worldwide.
Symptoms of Abetalipoproteinemia
Babies that are born with abetalipoproteinemia have problems with their stomach because their body cannot digest fats properly. Their stools are also abnormal with them being foul-smelling and pale colored. They can also have diarrhea, bloated bellies, and vomiting. The baby does not grow or gain weight like a normal baby would. Because their body has problems with digesting fats there are also problems with the vitamins that store the fat, which are called fat-soluble vitamins. These vitamins include vitamins E, K, and A.
Problems Caused by Abetalipoproteinemia
During their first ten years the problems that are caused by the lack of fat-soluble vitamins and fats start to show.
Some of the problems they might show include:
- Trouble walking (ataxia) — by the age of ten approximately thirty-three percent of children have this problem and as they age it becomes worse.
- Sensory disturbances — problems with sensing touch and temperature, especially in their feet and hands, which is called hypesthesia
- Movement disorders — tremors, trouble reaching for things, shaking, and trouble talking
- Muscle problems — shortening/contraction of muscles in their back that causes their spin to curve, weakness
- Blood problems — problems with clotting, low iron, abnormal red blood cells
- Eye problems — poor eyesight, problems with eye control, cataracts, night blindness
- Speech problems — slurred speech
Many of these problems are from the lack of absorption of vitamins, especially vitamin E.
Causes of Abetalipoproteinemia
When a person has abetalipoproteinemia they do not produce the critical “building block” or special protein that is used to make lipoproteins. If you do not produce enough of these lipoproteins the fats cannot be digested properly nor can they travel around your body to where they are needed. This can lead to serious health problems.
How is Diagnosis made?
Of course the first clue that the baby has abetalipoproteinemia is the problems they are having with their stomach. The physician will test their stool, which will show a high level of fat.
This means that instead of the fat being used by their body it is being eliminated in their stool. The physician will also have blood tests done to see if there are any abnormal red blood cells, which can be seen under the microscope. There will also be very low levels of fats such as triglycerides and cholesterol in their blood. There will tests done to see what their iron levels are and how fast their blood clots. If they do an eye examination it could show that there is inflammation in the back of their eye. The physician may order testing of their muscle contractions and strength to see if they are abnormal.
Treatment for Abetalipoproteinemia
It is important that this disorder be treated because it can cause vitamin deficiencies, which can have long-term effects on your health. The vitamins and dietary fats are important for the development and growth of many of your bodies systems, which includes your brain. Once there is an official diagnosis of abetalipoproteinemia, they will be put on a specific diet that has been developed for medical disorder. Some of the requirements of this diet include:
- Avoiding eating certain types of fats, which are called long-chain triglycerides and instead eating foods that are considered medium-chain triglycerides
- Adding doses of vitamin supplements that contain iron and vitamins K, A, and E
There will be a nutritionist that will work with the family to help them design the meal plans that will meet these dietary needs along with which type of formula would be best for the baby.
In most cases of abetalipoproteinemia taking high quantities of fat-soluble vitamins and following the special diet it may decrease the progression of this disorder, particularly with problems that are vision-related. The prognosis in this case is good. If it is a severe form of abetalipoproteinemia an individual may suffer from damage to their nervous system that is irreversible before they reach the age of thirty. Some of these particular complications can include damage to their nerves, deterioration of their mental ability, and blindness.