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
Carl Ritter Comparing Geography to language theory or philosophy, he believed that it was necessary to understand each "Erdgegend" (area of the Earth) and its characteristic appearances and natural relationships without relying on the absolute work of pure description and classification. In partitioning the Earth into "Erdgegende" he has developed a theory of area, which he views as indispensable to geographical inquiry. Furthermore, Ritter believed that areas existed a priori and were formed by humans. Constructing a geographical theory around the area allowed Ritter to make the comparative work would seek to do in the conclusion to his great work. Elevating the