Mucopolysaccharidosis VII in a cat

Area of Science:

• Veterinary Medicine
• Genetics
• Biochemistry

Background:

• Mucopolysaccharidosis VII (MPS VII) is a lysosomal storage disease caused by a deficiency in the enzyme beta-glucuronidase.
• This deficiency leads to the accumulation of glycosaminoglycans in various tissues, resulting in cellular dysfunction and multi-systemic abnormalities.

Observation:

• A domestic shorthair cat presented with a constellation of congenital abnormalities, including disproportionate body size, skeletal deformities (ribs, vertebrae, long bones, hips), tracheal hypoplasia, and corneal clouding.
• Biochemical analysis revealed markedly decreased beta-glucuronidase activity in peripheral blood leukocytes.
• Histopathological examination showed widespread distended lysosomes within epithelial and connective tissue cells.

Findings:

• The diagnosed case of Mucopolysaccharidosis VII in this cat exhibited a severe phenotype with extensive skeletal malformations and organ involvement.
• Deficient beta-glucuronidase activity was confirmed as the underlying biochemical defect.
• Ultrastructural analysis confirmed lysosomal distension, consistent with MPS VII pathology.

Implications:

• This case highlights the phenotypic variability and severity of Mucopolysaccharidosis VII in felines.
• Understanding the clinical and pathological features is crucial for accurate diagnosis and potential therapeutic strategies in affected animals.
• Further research into feline MPS VII can provide insights into lysosomal storage diseases in other species, including humans.