Spinal muscular atrophy is a rare and incurable disease. As a result of a mutation in the SMA gene, the body does not make enough of the proteins indispensable for the proper function of neurons (nerve cells). Neurons are used to transmit information to the brain, where they control muscle movement. The death of these nerve cells causes the muscles to gradually weaken and die (atrophy). The patient loses the ability to move, breathe and swallow.
Spinal muscular atrophy is a hereditary disease and around 10 children are born with it in the Czech Republic every year. Without treatment, the disease progresses rapidly and significantly shortens life expectancy. In the last 4 years there have been drugs available. Together with rehabilitation, they bring hope to children diagnosed with SMA. While they cannot cure the disease, they can slow down or even halt its progress.
SMA gene mutation is hereditary and passed from parent to child. The parent does not have to suffer from the disease. Each gene has 2 alleles (forms). If both alleles of the SMA gene are damaged, the disease will activate. If only 1 is damaged, the disease does not manifest itself. A person with 1 damaged allele is only a carrier who can pass on the mutated gene to his or her offspring. Each carrier has a 50% risk of passing on the mutated allele to their offspring. If both parents are carriers, the probability of having a child with both mutated alleles and SMA is 25%.
A healthy parent usually does not know in advance that he or she is a carrier of the mutated gene. He or she does not suffer from the problem and has probably never heard of the disease. Unfortunately, there is insufficient education. A simple blood test in pregnancy can determine whether the fetus carries the SMA gene mutation. In the future, prenatal diagnosis may be able to eradicate the disease completely.