A Drosophila model of mucopolysaccharidosis IIIB

Mucopolysaccharidosis IIIB (MPS IIIB) is a rare genetic disorder caused by defects in α-N-acetylglucosaminidase, which breaks down extracellular heparan sulfate. Symptoms progress from hyperactivity and sleep disruptions during childhood to severe neurodegeneration during adolescence. To generate an MPS IIIB model in the fruitfly, Drosophila melanogaster, we introduced mutations in the corresponding fly enzyme that correlate with patient mutations. The fly model recapitulates sleep fragmentation and hyperactivity observed in patients and enlarged lysosomes in the brain. Genes associated with synaptic function and neurodevelopment showed altered expression in the brain. The Drosophila model can enable future development of therapies for MPS IIIB. To investigate the differential gene expression in MPS IIIB progression, including the effects of various mutations, sex and age