Early Signs and Symptoms of Spinal Muscular Atrophy in Children

Early Signs and Symptoms of Spinal Muscular Atrophy in Children

Spinal muscular atrophy is usually observed in babies and children and is caused due to inheritance of a broken or mutated gene from both parents, which is found on chromosome 5. There are several types of SMAs, and their symptoms can range from mild to extreme. There are a total of five types of SMAs and are named type 0 to type 4, respectively. The severity of the condition depends on the amount of SMN protein present in the motor neurons.

Based on the severity, several symptoms can be observed early if the number of SMN proteins is less and the condition is considered to be more severe, whereas when the number of SMN proteins is more, the symptoms are observed later, and the condition is milder.

The following early signs can be observed in children suffering from SMA:

Type 0
When a baby is affected by type 0 spinal muscular atrophy, the symptoms can actually be felt by the mother later in her pregnancy. She may report a reduced amount of movement from the baby in the womb, and after the baby is born, it shows severe weakness, hypotonia, and heart defects or may even show facial paralysis.

Type 1
Newborn babies with type 0 SMA are usually very weak and find a lot of difficulty in supporting their head or sitting on their own. Such babies have weaker muscles and also often have difficulty in breathing, sucking, and swallowing. This condition is the most common type of spinal muscular atrophy and is also known as Werdnig-Hoffmann disease.

Type 2
This condition is observed in babies between the ages of 3 to 15 months. The symptoms are more commonly observed in the legs and can be moderate to severe. The weaker muscles are closer to the center, i.e., the core of the body, whereas the face and eye muscles remain unaffected. This condition is also called Dubowitz disease, intermediate SMA, or chronic infantile SMA.

Type 3
This type of AMA shows symptoms quite late and has milder effects on children. It is observed in children between 2-17 years, i.e., pre-teens and teens. Children suffering from type 3 SMA, which is the mildest form of spinal muscular atrophy, can walk and stand without much effort but find it difficult to run or climb flights of stairs. This condition could also lead to symptoms like foot deformities, scoliosis, and respiratory muscle weakness when transitioning to adulthood. The patient may feel the need to use a wheelchair later in life. It is also known as mild SMA, juvenile-onset SMA, or Kugelberg-Welander disease.

Type 4
This type of SMA is observed in adulthood with very mild symptoms. The person may experience some weakness in the thighs and upper arms muscles but can usually lead a full and ordinary life. Most symptoms can be controlled with the help of exercises and physical therapy.