Mucopolysaccharidosis VII

Mucopolysaccharidosis is a rare recessive genetic disease of cats, and a variant form of mucopolysaccharidosis.

Only a few cases have been reported.

Clinical symptoms are often seen in kittens at 12-14 weeks, including gait abnormalities, an enlarged abdomen, facial dysmorphism, plump paws, corneal clouding. Blood tests may show granulation of neutrophils, vacuolated lymphocytes. Urine test for sulfated glycosaminoglycans suggested mucopolysaccharidosis[1].

In most cases, the clinical course is progressive. All limbs may be affected with hindlegs exhibiting reduced proprioceptivity and reduced tactile reflexes, hyperreflexia (patellar and tibialis cranialis reflexes), and positive crossed extensor reflexes. Grand mal seizures may occur. Euthanized often results at 6 months of age[2].

In one case, radiographs were taken at 4 and 6 months of age. There was dysostosis multiplex characterized by widespread delay of ossification and fragmentation of epiphyses and apophyses. Femoral heads and necks were dysplastic, acetabulae were flattened, and hip joints subluxated. Delayed ossification of carpal bones was also evident. Intervertebral distances were increased, vertebral end plates were deformed and the spinal canal of cervical vertebrae was widened. Vertebral bodies had irregular trabeculae and were widened laterally, the atlas was bizarrely deformed, and the components of the hyoid apparatus were deformed. Radii were curved, and the humeroulnar and humeroradial joints were subluxated[3].

Definitive diagnosis is by enzyme assays on leukocytes and cultivated skin fibroblasts, which are deficient in 0-glucuronidase but competent in all other lysosomal hydrolases measured.


  1. ↑ Fyfe JC, et al (1999) Molecular basis of feline beta-glucuronidase deficiency: an animal model of mucopolysaccharidosis VII. Genomics 58(2):121-128
  2. ↑ Gitzelmann, R (1994) Feline mucopolysaccharidosis VII due to alpha-glucuronidase deficiency. Vet Pathol 31:435-443
  3. ↑ Schultheiss PC, Gardner SA, Owens JM, Wenger DA, Thrall MA. (2000) Mucopolysaccharidosis VII in a cat. Vet Pathol 37(5):502-505

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