Spinal muscular atrophy or SMA is a genetic condition that affects the muscles. It is amongst one of the most common rare diseases, affecting up to 25,000 children and adults. It generally affects children and babies. SMA is called an autosomal recessive disease because only when each parent carries the genetic mutation, then only the child has SMA. If someone in the family has SMA, then you might be at a higher risk of being an SMA carrier and passing it onto your child. SMA symptoms can vary depending on the type of SMA. The following are the early warning signs of spinal muscular atrophy according to type.
Type 1
Also known as Werdnig-Hoffman disease, this type of SMA is severe. Your child will exhibit symptoms such as being unable to sit unless you help him. He might have trouble supporting his head. You might notice he is unable to swallow his food, which can lead to feeding issues. He might have floppy legs and arms. When your child has this type of SMA, the chances of him surviving past the age of two is quite low. Children die due to this because of respiratory failure.
Type 2
This type of SMA is known as chronic infantile SMA, and it affects children between 6 months and 18 months old. One of the early warning signs of spinal muscular atrophy for this type is difficulty in standing without help. Your child may have trouble sitting and walking without support too. The symptoms can be mild but can be severe for some children. Your child may have tremors in fingers, and you might notice scoliosis. Scoliosis is when the spine is abnormally curved to one side. Your child may show symptoms that point to respiratory muscle problems.
Type 3
Type 3 SMA is known as juvenile SMA or Kugelberg-Welander disease. There are many early warning signs of spinal muscular atrophy for this type of SMA. This type can affect children, aged between 2 and 17. It is the mildest type of SMA. In this, your child will be able to walk and stand without help. However, when it comes to getting up from a chair, he will need your help. Your child might have symptoms such as problems climbing stairs and an inability to run. Your child might require a wheelchair to move around. People with this type of SMA can expect to have a normal life expectancy.
Type 4
Type 4 SMA is rare. You might not notice the symptoms until the second decade or the third decade of your life. There are some early warning signs of spinal muscular atrophy, but they can vary from person to person. You might have breathing issues when you have this type of SMA. You might have twitching or muscle weakness when you have this type of SMA. Generally, people with this type of SMA experience problems in using legs and upper arms. You might experience tremors due to this condition. Life expectancy is normal for a person with this type of SMA.
