Spinal Muscular Atrophy (SMA) is a neuromuscular disease that exhibits different onset ages and symptoms depending on its types.
* Type I SMA: Typically appears within the first 6 months after birth, often starting from the 3rd month. Infants experience severe muscle weakness.
* Type II and III SMA: These types generally begin to show symptoms in children between 7 and 18 months of age. Significant weakness is observed in muscles close to the trunk; children may sit independently but struggle to walk or may not be able to walk at all.
The most common symptoms of SMA include:
* Widespread muscle weakness and limited mobility
* Delay or regression in gross motor skills such as sitting, crawling, and walking
* Muscle twitching and involuntary tremors (especially in the tongue and hands)
* Weak head control
* Difficulty with sucking, swallowing, and chewing
* Respiratory difficulties
* Weak or faint voice tone
* Reduced reflexes
* Frequent falls, decreased walking ability, or complete loss of walking ability
* Difficulty standing up from a seated position on the floor
* Spinal and joint deformities such as scoliosis
* Muscle cramps
* Developmental delays in infants compared to their peers