Mucopolysaccharidosis VII (MPSVII)

After careful consideration, the VGL is discontinuing the Mucopolysaccharidosis VII (MPSVII) test. While the VGL offered this test, no cats were found with this mutation. The genetic defect was discovered in a random-bred cat that was subsequently used to establish a breeding colony. The disease may be limited to that colony and be absent, or extremely rare, in cat breeds.

This test is no longer available.

Mucopolysaccharidosis VII (MPSVII) is a progressive, autosomal recessive disorder resulting from a single mutation in the GUSB gene that produces lysosomal enzyme B-glucuronidase.  Disruption of this enzyme results in dermatan sulfate, heperan sulfate and chondroitin sulfate accumulation.  By three months of age affected cats show clinical signs that include gait abnormalities, possibly due to muscle weakness, as well as bone abnormalities, disproportionate skull to body ratio, plump paws and corneal clouding, among other defects.  Most affected animals must be euthanized by 6 months.


Fyfe, JC, RL Kurzhals, ME Lassaline et al. 1999. Molecular basis of feline B-glucuronidase deficiency: an animal model of mucopolysaccharidosis VII. Genomics 58:121-128.