Every child reaches a motor milestone two years after being born. The child will begin to grasp, pull, roll over, crawl, sit, stand with/without support, and finally begin to walk. A child affected by SMA will not be able to reach many of these milestones. There are other symptoms too that parents should watch out for before the onset of spinal muscular atrophy (SMA).

Symptoms of Type 1 SMA

Among most SMA cases, the most common ones include Type 1 SMA. The infants develop symptoms right after birth or within six months. They will be unable to sit up on their own. They will show signs of paradoxical breathing. When we breathe, our chest wall goes in when we inhale and expands when we exhale. The reverse happens when SMA affects a child. The child will also face tongue fasciculations, where the tongue muscles contract spontaneously. The infant will find it difficult to swallow or suckle. With weakness caused by a low intake of food, the child could become floppy. Most infants cannot hold their heads, and a few will sit only with support. Other symptoms include breathing difficulties, and infants are most likely to develop pneumonia.

Symptoms of Type 2 SMA

These symptoms start showing between the ages of 6 and 18 months. The child will be able to sit or stand without support, but they won’t be able to walk without assistance. Some kids will develop mild tremors in the limbs. One of the most visible symptoms that a child could develop is that the spine will curve on both sides — backward or forward. They will have chewing and swallowing difficulties, tongue fasciculations, and contractures of the joints. The muscles will be weaker, and they may face severe breathing difficulties, requiring external support like ventilators.

Symptoms of Type 3 SMA
The children affected by SMA will be able to achieve most of the significant age-appropriate milestones. Some will even be able to walk independently. However, while some begin to get worse, many continue walking. They will find it challenging to get up from a sitting position. Climbing the staircase will be difficult as the muscles get weaker. Many develop deformities in the foot. Because they have mobility issues, many with Type 3 SMA are at high risk of becoming obese. While some with Type 3 SMA might be unable to walk after 10, many continue to walk until about the age of 40.

Symptoms of Type 4 SMA
SMA type 4 symptoms manifest when a person is around 40. The symptoms and complications in this stage are mild.

Other symptoms
Apart from the symptoms mentioned above, patients are likely to be affected by gastrointestinal problems and cardiac issues like atrial septal defects. They are at risk of autonomic abnormalities like dizziness and fainting when they stand up and could also experience hormonal imbalances.