Mucopolysaccharidosis type IIIb ( MPS3B ) is an inherited lysosomal storage disease affecting the Schipperke breed. It is also known as “Sanfilippo syndrome type IIIb”. Lysosomes are important cell structures that disassemble large molecules using enzymes in order to recycle or dispose of the molecules. In the case of Mucopolysaccharidosis type IIIb disease, the heparan sulfate molecules cannot be disassembled due to a defective enzyme, and therefore 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-to-cell communications, especially in the brain. Typical symptoms of this disease include 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.
