The Dwarf Pony

Mucopolysaccharidosis Type IVA

In mucopolysaccharidosis type IVA (MPS IVA, Morquio disease A, deficiency of the enzyme Acetylgalactosamine-6-Sulfatase) predominantly the skeletal system is affected: Severe deformities of the spine, thorax and extremities result in disproportionate short stature, in severe cases the final height is about 120 cm. However, patients with a normal height have been described, too. Further characteristic features include joint laxity, instability of the cranio-cervical junction, leading to paraplegia, corneal clouding and hearing problems. The intelligence is normal.