In contrast, Andersen Disease, or Glycogen Storage Disease Type IV (GSD IV) and its adult-onset counterpart Adult Polyglucosan Body Disease (APBD), are autosomal recessive disorders that affect mitochondrial function indirectly through mutations in the GBE1 gene, which encodes the glycogen branching enzyme (GBE). This evidence concerns the gene GBE1 and adult polyglucosan body disease.