Spinal Muscle Atrophy or SMA is a hereditary disease that affects the spinal cord, gradually attacking the lower motor neurons, causing the muscles to get weaker.

The symptoms of spinal muscular atrophy significantly vary depending on the type of condition. SMA in children is divided into three types: type 1, type 2, and type 3; whereas, type 4 is an adult-onset.

Here are the signs and symptoms of SMA disease that one should look out for:

Type 1
In this type of SMA disease, an infant may experience muscle weakness that controls breathing. It is the most serious type of condition as the affected child may develop floppy legs and arms and have difficulty swallowing.

The symptoms of this type are evident by the time the child is 6 months old. It has been observed that most children with type 1 SMA disease do not live past the age of 2. This is primarily due to breathing problems. Some children with type 1 SMA disease may also develop a condition called scoliosis, the bending of the spine or other skeletal anomalies.

Type 2
Also known as chronic infantile SMA, this affects children between the age of 6 to 18 months. The symptoms of type 2 condition range from moderate to severe and it affects the legs more than the arms.

Type 3
Signs of the type 3 SMA disease start showing in children between ages 2 to 17. They may have an abnormal gait and this is also known as juvenile SMA or Kugelberg Welander disease. The symptoms may include problems like climbing the stairs, running or getting up from a chair, etc. However, children experiencing this condition may be able to walk or stand with help. In most cases, the affected children may need a wheelchair as they grow.

Type 4
Type 4 SMA disease starts during adulthood, typically after the age of 35. Some of the alarming symptoms of this condition include twitching, muscle weakness in the hips and legs, and breathing problems. In most cases, only the legs and upper arms are affected.