Cats with MPS VI which show the severe phenotype exhibit dwarfism and facial dysmorphia due to... more
Mucopolysaccharidosis Type VI is a lysosomal storage disease caused by a deficiency of N-acetylgalactosamine-4-sulfatase (4S). This deficiency is caused by two different mutations in the 4S-gene, resulting in a clinically mild and a severe MPS VI phenotype. Cats which show the severe phenotype exhibit dwarfism and facial dysmorphia due to epiphyseal dysplasia, abnormally low leukocyte 4S/ß-hexosaminidase ratios, dermatan sulfaturia, lysosomal inclusions in most tissues including chondrocytes, corneal clouding, degenerative joint disease and abnormal leukocyte inclusions. Cats with the mild phenotype show similar but milder symptoms and have normal growth and appearance.