Correction of feline arylsulphatase B deficiency (mucopolysaccharidosis VI) by bone marrow transplantation

Feline and human mucopolysaccharidosis VI (MPS VI or Maroteaux–Lamy syndrome) are inherited autosomal recessive deficiencies of lysosomal enzyme arylsulphatase B 1–6 . Affected cats and children exhibit lesions caused by incompetent degradation, retinal atrophy and excessive urinary excretion of dermatan facial dysmorphia, corneal stromal opacities, leukocyte granulation, retinal atrophy and excessive urinary excretion of dermatan sulphate—and usually die before adulthood 7–11 . Most attempts to treat humans affected with MPS VI or other mucopolysaccharidoses have been ineffective or logistically prohibitive 12–21 , but allogeneic bone marrow transplantation (BMT) offers promise for cure of certain inborn errors of metabolism 22–24 . Engraftment of normal donor marrow may endow the enzyme-deficient recipient with a continuous source of enzyme-competent blood cells and tissue macrophages to facilitate degradation of stored substrate and to prevent genesis of further malformations. To test this hypothesis, we performed allogeneic BMT in a 2-year-old male Siamese cat with advanced MPS VI. Here we describe BMT-induced correction of this hereditary enzyme deficiency.