GBE1 and glycogen storage disease due to glycogen branching enzyme deficiency: Adult polyglucosan body disease (APBD) is another kind of heritable glycogen storage disease (GSD) often associated with glycogen-branching enzyme (GBE) deficiency, which causes a neurodegenerative disorder due to an accumulation of abnormal polyglucosans in the cells of various body systems of humans and horses [18,19].