Main things families often see:
Weak or floppy muscles at birth or in early infancy. Babies may be slow to reach motor milestones (hold head up, roll, sit, walk).
Breathing or feeding problems in more severe cases; some babies need help with breathing or tube-feeding.
Heart problems: some children develop an enlarged, weakened heart (dilated cardiomyopathy) that may need medicines or surgery. Regular heart checks are very important.
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