Spinal muscular atrophy is a motor neuron disease that impacts a person’s ability to move their muscles. It is a genetic disease and it is caused by a loss of nerve cells in the brain stem and spinal cord.

There are different types of the condition that are classified depending on when the symptoms manifest in the patient. It is possible for the disease to be present at birth or to show at different stages of infancy, which has a differing impact on how the disease affects the person. It is rare to have this disease affect an adult but cases have known to occur. The disease has no cure but there are treatment options for spinal muscular atrophy (SMA) that help manage the disease and slow its progress.

Diagnosis
The diagnosis of the disease can be done during the fetal stage if tests confirm that there is little movement of the fetus. It can also be seen as soon as the child is born. Some states advise that genetic screening should be done at birth to rule out this disease. This is because the treatment to manage the disease can be started even before the symptoms appear, which will have a better impact on slowing the progress of the disease. However, the diagnosis of SMA usually happens when the caregivers of the patient notice the signs in their infant. The test includes a physical examination that will help the doctors study how flaccid the muscles are and also test the reflexes that involve deep tendons and the tongue muscle. Blood tests, electromyography (EMG) and muscle biopsy might be performed. A genetic test can also be used to check a fetus in the womb for this disease through chorionic villus sampling or amniocentesis during gestation.

Treatment options for spinal muscle atrophy
There is no cure for the disease as of now. Treatment options for SMA are currently limited to slowing the disease and trying to improve the patient’s outlook. Disease-modifying therapies or DMTs help to reduce the severity of the symptoms. There are currently two approved drugs for SPA in the market and there are more in development. The two drugs that are approved by the FDA for SPA are SPINRAZA® and ZOLGENSMA®. Both these drugs are not without risks as they can cause adverse effects. The drugs that are being developed include those for gene replacement therapy. There is also ongoing research into the treatment options for SMA with stem cells in order to replace damaged motor neurons.

SPINRAZA®
This is a drug that is classified as an antisense oligonucleotide (ASO). These drugs are targeted at the RNA production of the body and improve the splicing of the SMN2 gene. It is suitable for all the different types of SMA. The dosage pattern is to inject 4 doses over a certain period. This is then followed by a maintenance dose every 4 months. It is found that the drug reduces muscle weakness in some patients, which helps to slow down the disease. However, there is a lot of variation of results from patient to patient.

ZOLGENSMA®
Zolgensma is a gene therapy drug. It is used on infants who are below the age of 2 years and is given as a single dose by infusion.