Symptoms vary a lot, depending on the type of SMA:
Type 0. This is the rarest and most severe form of SMA and develops while you’re still pregnant. Babies with this type of SMA move less in the womb and are born with joint problems, weak muscle tone, and Weak muscles for breathing. They often do not survive due to breathing problems.
Type 1. This is also a severe type of SMA. A child may not be able to support their head or sit without help. They may have floppy arms and legs and problems swallowing.
The biggest concern is Weakness in the muscles that control breathing. Most children with type 1 SMA don't live past age 2 because of breathing problems.
Keep in touch with your medical team, family members, clergy, and others who can help give you the emotional support you need while your child fights this disease.
Type 2. This affects children 6-18 months old. The symptoms range from moderate to severe and usually involve the legs more than the arms. Your child may be able to sit and walk or stand with help.