They took him to the Mayo Clinic in Minnesota where he underwent several tests. Doctors also sent a skin graft to a lab in Australia for testing. That led them to determine that Keenan had a severe form of an extremely rare disorder called Maroteaux-Lamy Syndrome, also known as MPS, type 6.
People who have the disease are unable to break down complex sugars called mucopolysaccharides, which accumulate in connective tissue and organs throughout the body. Fewer than 1,100 of people worldwide have the disease, which leads to severe disability and a shortened life span in most cases.
Doctors told Keenan’s parents that their son would likely be in a wheelchair by the end of his teenage years if he was not treated. His growth would be extremely hampered, though with this particular type of MPS, there would be no cognitive impairment.
h/t to The Blaze