I would speak to your pediatrician about the low muscle tone--especially if
he's missed motor milestones like climbing stairs, jumping, riding a tricycle.
You may get a referral to a neurologist or geneticist to have him assessed
for other medical issues. You also may have him assessed by your local school
district when he's three to see if he needs PT/OT or speech therapy (OTs and
speech therapists both can work on oral motor issues). My son who has reflux
also has muscular dystrophy. His Pedi Gastroenterologist said low muscle tone
in the mouth, and GERD are not uncommon in children with neuromuscular
diseases.

Carol Cohen