Mucopolysaccharidosis type IIIb (MPS3b)

The disease Mucopolysaccharidosis type IIIb in the breed Schipperke is a lysosomal storage disease that is also known as “Sanfilippo syndrome type IIIb”. Lysosomes are important cell structures that disassemble large molecules by the use of enzymes in order to recycle or dispose the molecules. In the case of the disease Mucopolysaccharidosis type IIIb, the molecule heparan sulfate could not be disassembled because of a defective enzyme so that the undegraded molecule accumulates in the lysosomes. Heparan sulfate is an important component of structures like bones and cartilage and is known to be implicated in cell-cell-communications, especially in the brain. Typical symptoms of this disease are: tremor, difficulties in balancing, walking and negotiating obstacles and falling to both directions. Furthermore, the symptoms are progressive and initial problems with balance become worse. The age of onset varies between 2-4 years. Affected dogs usually are euthanized 1-2 years after first clinical signs.