A key enzyme in glycogen degradation and metabolism, GANC (glucosidase, α neutral C) is a 914 amino acid protein with α-glucosidase activity that belongs to the glycosyl hydrolase 31 family and hydrolyzes non-reducing, terminal 1,4-linked α-D-glucose residues and releases α-D-glucose. The gene encoding GANC maps to human chromosome 15q15.1, a region associated with susceptibility to non-insulin-dependent (type 2) diabetes mellitus, a disease characterized by high blood glucose levels. Human chromosome 15 houses over 700 genes and comprises nearly 3% of the human genome. Angelman syndrome, Prader-Willi syndrome, Tay-Sachs disease and Marfan syndrome are all associated with defects in chromosome 15-localized genes.