MCAD deficiency (MCADD), also known as medium chain acyl CoA dehydrogenase, is an inherited disorder. It is a genetically autosomal recessive disorder, that is caused by mutation in MCAD gene. The symptoms of MCAD deficiency are usually seen when an affected person goes through prolonged periods of fasting, or through an illness or severe vomiting. The typical sign of this condition is a dangerous hypoglycemia and a sudden death.
Life Expectancy For MCAD Deficiency
The primary focus of the treatment and management is to avoid prolonged fasting periods, any illnesses and severe vomiting, to increase the life expectancy in MCAD deficiency. With proper guidance regarding the diet and avoiding the triggering factors like prolonged fasting, illnesses and severe vomiting, life expectancy in MCAD deficiency can be increased.
- Once MCAD deficiency is diagnosed, the affected individual can lead a normal o near-normal life.
- Diagnosing the MCAD deficiency as early as possible is of utmost importance.
- The prognosis is good once a confirmed diagnosis has been made.
- The most important factor to be followed is to avoid any prolonged duration of fasting and taking proper precautions to avoid falling sick often.
Let us have a look at the mechanism of action of this condition and the strategies used for its treatment and management in a little detail, so that we can understand the life expectancy factor associated with MCAD deficiency.
- With the advent of science and availability of MS newborn screening option these days, it is possible to identify MCAD deficiency in newborns and infants within a few hours of their birth.
- In past years, when this screening was not available, the possible way of diagnosing this condition in people was when they presented with symptoms like hypoglycemia or sudden death.
- Hence, major part of the treatment focused on managing the symptoms that the people presented with.
Also, most of the times it so happened that the condition was suspected in people with sudden death and most of the times diagnosis was confirmed post-mortem. This is because, the affected person usually stays asymptomatic till he is exposed to triggering factors. Once exposed, the first episode can be the most severe one, leading to a sudden death.
However, with MS newborn screening option available these days, it is possible to identify infants suffering from this condition quite early in their lives and thus, it is possible to prevent the serious effects of this condition.
The major part of the treatment these days focuses on strategies to prevent MCAD deficiency from occurring and preventing the state of metabolic decompensation.
How Does MCAD Deficiency Disorder Work?
- The foremost source of energy in cells of our body is carbohydrates and glucose.
- When our body undergoes a short period of fasting, the stored glycogen is used as a source of energy to derive glucose.
- When all the glucose stores in the body start to deplete, it is then that the stored fats are used as a source of energy.
- The stored fats are oxidized by enzymes that are chain-length specific.
- The long chain fatty acids are broken down and they reduce to a chain length of 8-10.
- The enzymes that are medium chain-length specific are then used to oxidize these fatty acids.
- In MCAD deficiency, these enzymes are either deficient or totally absent.
- This hampers the oxidation of medium chain fatty acids and as a result they cannot be broken down to obtain energy.
- As the fats cannot be used as a store to obtain energy, the body starts going into hypoglycemia, as all the glucose stores have already been used completely, especially when there has been prolonged duration of fasting or high energy requirements like those in an illness.
- The body produces ketones in a limited quantity, which are otherwise seen in abundance in the state of fasting.
- Thus, the hypoglycemia is hypoketotic a well.
- There can be other symptoms like lethargy.