SMA type 1
SMA is the leading genetic killer of children under 2 years.
What is SMA?
Spinal Muscular atrophy is a hereditary neuromuscular disease.
Approximately every 40th person carries the gene for SMA. If parents are carriers , it is 25 % chance that the child has SMA, you must inherit the gene from both parents to actually get the disease. There are different variations of SMA, the most common is type 1 , and it’s also the most serious type. 4-6 children are born with SMA type 1 per year in Sweden and Switzerland. In the U.S., a child with SMA is born every 12 hours!
How SMA works
SMA causes muscle wasting (atrophy ) in all the body’s voluntary muscles. Muscle weakness is due to a deficiency of a protein called SMN1. This allows the motor neurons in the midbrain, medulla oblongata and spinal cord anterior horn to break down. In turn, this means that the signals sent from the brain to the muscles can not reach its full strength and it causes muscle wasting.
How do you recognise that it’s SMA?
SMA type 1 noticed within the first 6 months of a child’s life, and it manifests as muscle weakness. The child is quiet and never learn to walk, stand or even sit without support. Sucking and swallowing functions often disappear quickly and the child has difficulty eating. Breathing problems are common because the chest muscles are weak. Therefore, the child don’t have the capacity to scream out loud, like most other babies. Characteristic of SMA type 1 is small tremors / muscle spasms in the tongue.
Intellect is not affected by SMA. The child will usually follow normal mental development and make eye contact and smile just like other children to the extent that muscle strength is sufficient.
SMA type 1 leads to death
Because breathing is so impaired, there is a high risk of pneumonia and other infections. When combined with progressive muscle weakness makes it that many children with SMA type 1 die of respiratory failure before the age of three, most often during the first year of life.