- SMA is the #1 genetic killer of infants and young children
- 1 in every 40 people or nearly 10 million Americans UNKNOWINGLY carry the gene responsible for SMA
- 1 in 6,000 babies are effected every year.
- SMA is does not discriminate based on race, ethnicity, or gender
There is currently no treatment and no cure, but the National Institutes of Health (NIH) and the National Institute of Neurological Disorders and Stroke (NINDS) selected SMA as the disease closest to treatment of more than 600 neurological disorders.
Researchers estimate that we are as close as only a few years away from finding a treatment and/or cure.
As a child with SMA grows their bodies are doubly stressed, first by the decrease in motor neurons and then by the increased demands on the nerve and muscle cells as their bodies grow larger. The resulting muscle atrophy can cause weakness and bone and spinal deformities that may lead to further loss of function, as well as additional compromise of the respiratory (breathing) system.
The most severe form of SMA is Type I and is also called Werdnig-Hoffmann Disease. Type 1 is fatal in most cases, usually by age one and parents are told that their child will not see their second birthday! The diagnosis of children with this type is usually made before 6 months of age and in the majority of cases the diagnosis is made before 3 months of age. Some mothers even note decreased movement in of the final months of their pregnancy.
Usually a child with Type I is never able to lift his/her head or accomplish the normal motor skills expected early on in infancy. They generally have poor head control, and may not kick their legs as vigorously as they should, or bear weight on their legs. They do not achieve the ability to sit up unsupported. Swallowing and feeding may be difficult and are usually affected at some point, and the child may show some difficulties managing their own secretions. The tongue may show atrophy, and rippling movements or fine tremors, also called fasciculations. There is weakness of the intercostal muscles (the muscles between the ribs) that help expand the chest, and the chest is often smaller than usual. The strongest breathing muscle in an SMA patient is the diaphragm. As a result, the patient appears to breath with their stomach muscles. The chest may appear concave (sunken in) due to the diaphragmatic (tummy) breathing. Also due to this type of breathing, the lungs may not fully develop, the cough is very weak, and it may be difficult to take deep enough breaths while sleeping to maintain normal oxygen and carbon dioxide levels.
SMA is an autosomal recessive genetic disease. In order for a child to be affected by SMA, both parents must be carriers of the abnormal gene and both must pass this gene on to their child. Although both parents are carriers the likelihood of a child inheriting the disorder is 25%, or 1 in 4.