A rare autosomal recessive lysosomal storage disease caused by deficiency of the enzyme galactosamine-6-sulfatase. It is characterized by skeletal and central nervous system deficits. The disease is MONDO_0009659 (mucopolysaccharidosis type 4A). Also known as: GALNS deficiency, MPS IV A, MPS4A, MPSIVA, Morquio disease type A, Morquio syndrome A, N-acetylgalactosamine-6-sulfate sulfatase deficiency, galactosamine-6-sulfatase deficiency.