Adult polyglucosan body disease body disease do not have identified mutations in the "GBE1" gene. In these individuals, the cause of the disease is unknown. Along with evaluation of the symptoms and a neurological examination, a diagnosis can be made based on genetic testing. Whether or not a person is making sufficient amounts of functional glycogen branching enzyme can be determined by taking a skin biopsy and testing for activity of the enzyme. Examination of tissue biopsied from the sural nerve under a microscope can reveal the presence of polyglucosan bodies. There will also be white matter changes visible in a magnetic resonance imaging
Adult polyglucosan body disease cases had been reported in the medical literature as of 2016. As of 2016 the largest set of case studies included 50 people; about 70% of them were of Ashkenazic Jewish descent. A person with APBD named Gregory Weiss created a foundation, the Adult Polyglucosan Body Disease Research Foundation, to fund research into the disease and its management. In 2015 the first transgenic mouse that appeared to be a useful model organism for studying APBD was published. Adult polyglucosan body disease Adult polyglucosan body disease (APBD) is an orphan disease and a glycogen storage disorder that is caused by an