Ruth,
Has Jack been checked to make sure his foramen magnum is still large
enough?  Some people with achondroplasia need surgery to enlarge this
opening at the base of the skull to prevent compression of the spinal
cord/base of the brain.
        The other thing I would look at is his palate.  Sometimes a
tongue-tie can lead to a very high palate, which can impinge on the nasal
pharynx, leading to sleep apnea.  This is extremely young to have sleep
apnea.  If it is central apnea, look to the above instead, perhaps the
medula is being compressed.
        For more information, she could contact Little People of America.
I beleive they are based in California.
--
Catherine Watson Genna, IBCLC  NYC  mailto:[log in to unmask]