Craniofacial abnormalities in animal models of mucopolysaccharidoses I, VI, and VII.

The genetic mucopolysaccharidoses (MPS) are a family of lysosomal storage diseases resulting from the partial catabolism of several glycosaminoglycans (GAGs). Depending on the particular enzyme deficient in activity, the MPS syndromes are defined into groups MPS I through VII, with several subgroups for a total of 10 disorders. In humans, clinical features include dysostosis multiplex, hepatosplenomegaly, hypertelorism, macroglossia, hypoplastic and irregularly shaped teeth, hyperplastic lips and gingiva, facial dysmorphia, corneal clouding, and mental retardation. MPS I (alpha-L-iduronidase deficiency) and VI (arylsulfatase B deficiency) have been described in cats, MPS VII (beta-glucuronidase deficiency) in dogs. Biochemically, these syndromes appear the same as their human counterparts and have similar clinical characteristics. All are inherited as autosomal recessive traits. The purpose of this study was to analyze the craniofacial aspects of these diseases in the animal models and compare these data with descriptions of the human syndromes. A total of 28 live animals were examined. Thirty-one skulls prepared from postmortem specimens were measured directly and radiographed. Controls were closely related family members of the same sex and similar age without the disease, clinically or biochemically. The data indicated that, as in the human syndromes, each is distinct, and the skull bones most severely affected are those of endochondral origin.