What is SMA?
Spinal Muscular Atrophy (SMA) is the number one genetic cause of death in infants and toddlers. SMA is a motor neuron disease in which the muscles of the body waste away and eventually die.
How common is SMA?
SMA occurs in about 1 in 6,000 births.
Does SMA cause mental disabilities?
No. SMA affects only a child’s physical abilities.
What are the symptoms?
There are three main types of SMA.
- Type 1 — This is the most severe and most common form of SMA. It’s usually diagnosed before 6 months of age. Symptoms may include inability to lift head and feeding and/or breathing difficulties. The life expectancy is usually around 2 years old.
- Type 2 — Initial symptoms usually include inability to crawl or stand. Sitting unsupported is usually the last developmental milestone reached by these children. Most are diagnosed by 15 months of age. Life expectancy is highly varied.
- Type 3 — These children are usually diagnosed around the age of 3. Most Type-3 children can walk and symptoms may include inability to run and jump. Many parents also report their children also fall down easily and have difficulty getting up from a sitting position. Although the life expectancy may not be affected, they will continue to weaken, with most losing the ability to walk.
How do you get SMA?
The absence of a gene called SMN1 causes SMA. Both parents must be genetic carriers of the condition to have a child with SMA. About 1 in 40 people are SMA carriers, and most don’t know it until they have a child with SMA.
What are the chances of having a child with SMA?
Both parents must be SMA carriers to have a child with SMA. When both parents are carriers, each pregnancy has a 25 percent chance of resulting in a child with SMA.
How do I know if my child has SMA?
A genetic test is considered standard confirmation. The test will usually show that the child is missing the SMN1 gene. However, other tests and symptoms the child exhibits can point to SMA.
How is SMA treated?
There is no cure for SMA. All therapies are considered supportive care. SMA patients require numerous specialties, some of which include pulmonology, orthopedics, nutrition and physical therapy so the child can have maximum function and the highest quality of life possible.
On Dec. 23, 2016, the FDA approved the first medicine for children with spinal muscular atrophy. Newly diagnosed children who have received the new drug, Spinraza, have shown more ability to reach developmental milestones. It is still not clear what affects the drug could have on older children.
What is SMN2?
SMN2 is a “backup” gene for the missing SMN1 gene. It could operate exactly as SMN1, but does not. Many therapies being explored focus on SMN2. The number of SMN2 copies an individual has is highly predictive of SMA severity. Those with only one or two copies of SMN2 typically have more severe presentations of SMA than those with 3 or 4 copies.
What can I do?
You can help by donating to SMA research, helping organize fund-raisers and by asking your representatives in Washington, D.C., to support legislation that would accelerate SMA research.