SMA (Spinal Muscular Atrophy), a genetic disease, is common in the world and in our country. According to the data of the World Health Organization, 30 out of every 1 people is a carrier, and 10 out of every 1 thousand people has SMA. For SMA to occur, both genes must have mutations. The fact that both parents carry this mutation gene increases the risk of the child to be born with SMA to 25%. While SMA does not cause any symptoms and risks in carriers; Depending on the weakening of the nerves controlling the muscles in patients, progressive muscle weakness may occur over time. It may be sufficient to have a practical blood test to find out whether the person is a carrier of SMA. Prof. from Memorial Şişli Hospital Genetic Diseases Evaluation Center. Dr. Mustafa Özen shared important information about the prevention of SMA disease.
SMA can cause severe weakness and breathing problems
SMA (Spinal Muscular Atrophy) is an inherited genetic disease. It manifests itself with muscle weakness that progresses over time due to the weakening of the nerves that control the muscles. The severity varies according to the type of the disease. The most severe form of the disease is Type 0. Patients in this situation face severe weakness and serious respiratory problems from birth. In the most common type 1 SMA, symptoms begin to appear in the first 6 months. Although it is not as severe as type 0, muscle weakness, feeding difficulties and respiratory problems can be seen in this type. In the type 2 form, symptoms appear between 6 and 18 months. These patients are usually able to sit independently but cannot walk without support. Type 3 SMA is seen from 18 months to adult ages. These patients can gain the ability to walk on their own. However, these patients may not be able to climb stairs in later ages and may lose their abilities due to muscle use.
Children of parents who carry the mutation are at risk
SMA is inherited recessively. In other words, both genes must be mutated for the disease to occur. The fact that both parents carry mutations increases the risk of having a child with SMA to 25%, and the risk of having a genetic carrier child to 50%.
You can find out if you are a carrier with a blood test.
Since SMA is a common disease in our country, it is very important for parents to have a carrier test. It is known that more than 95% of the mutations are caused by a deficiency in the SMN1 gene. For this reason, it is possible for parents to learn whether their children carry this mutation with a simple blood test in order to prevent their children from being born with this disease risk. After examining the mutations seen in more than 95%, the results are shared with genetic counseling. Other rare mutations can be examined with additional tests when necessary.