Disorder - Mucopolysaccharidosis VIOrgan Systems Involved
Arylsulfatase B deficiency
Mucopolysaccharidosis VI is a disorder caused by a deficiency of a certain enzyme (a substance which increases the rate of chemical reactions) so that certain metabolic processes cannot occur. It leads to skeletal and facial deformity, and often nervous system defects due to a build-up of unmetabolised substances.
Mucopolysaccharidois has several different types, all of which have the same clinical signs. Mucopolysaccharidosis VI can only be diagnosed and distinguished from types II-VII in the laboratory through a urine sample test. The signs of mucopolysaccharidosis are failure to thrive as a puppy (i.e. failure to gain weight), dwarfism and facial deformities. Skeletal abnormalities are usually obvious, with the affected animal having difficulty walking, disproportionate size and shape of limbs and such signs as inward-turning feet. Affected animals may have breathing difficulty and heart problems, and this could lead to a reluctance to exercise. Due to possible defects of the retina (the back layer of the eyeball which collects information to be sent to the brain) these animals could have difficulty with vision. This is usually demonstrated when affected dogs fail to recognise familiar things and collide with objects such as furniture. Visually impaired dogs may also be more timid or aggressive than normal.
Mucopolysaccharidosis I (MPS I)
Further Reference Material [OMIA Number]