SPINAL MUSCULAR ATROPHY (SMA)
Spinal Muscular Atrophy is an inherited genetic condition that affects the anterior horn cells of the spinal cord. These anterior horn cells are responsible for controlling voluntary muscles such as crawling, walking, head and neck control, swallowing and breathing.
There are 3 main types of SMA, all of which vary in severity and age of onset. One common observation is that SMA children are unusually bright and sociable.
Diagnosis is usually made before the age of 6 months. This is the most severe form of SMA. These babies rarely make it to the age of 2, most die before 1 year due to breathing difficulties like pneumonia. SMA Type 1 babies never are able to lift their heads, or accomplish normal milestones. Some children have a tongue tremor called tongue fasciculation. This is seen in virtually no other disease other than SMA.
Because this disease also affects swallowing and feeding, secretions become increasingly hard to control and mechanical suctioning is needed. Upon X-ray of the chest, Type I babies can have a bell shaped rib-cage due to the general muscle weakness and diaphragmatic breathing (tummy breathing)
Diagnosis is usually made before the age of 2. A less severe disease than Type 1, these children may be able to sit unsupported. Some are even able to stand with the help of braces or other aids. Feeding is not usually a problem with type 2, although some may need to have a feeding tube put in.
This type is diagnosed sometime after the age of 18 months, even up to adolescence. These children are able to stand by themselves and walk, but may have some difficulties.
FACTS ABOUT SMA
- SMA is an autosomal recessive disease, this means that both parents must be carriers
- 1 in 40 people carry the gene (gene deletion) responsible for SMA
- 1 in 6000 live births are affected
- SMA is the #1 genetic killer of babies under the age of 2
- 1 in 4 chance with each pregnancy of having an affected child (25%)
- Does not discriminate based on age or race or gender
- there is no treatment
- there is no cure