LGA is a 602 amino acid protein that localizes to the mitochondrion and contains two ANK repeats. Expressed in brain, liver and pancreas, LGA functions as a mitochondrial phosphate-activated glutaminase that catalyzes the hydrolysis of glutamine to glutamate and ammonia. LGA is overexpressed in breast cancer cell lines, suggesting a role for LGA in tumorigenesis. The gene encoding LGA maps to human chromosome 12, which encodes over 1,100 genes and comprises approximately 4.5% of the human genome. Chromosome 12 is associated with a variety of diseases and afflictions, including hypochondrogenesis, achondrogenesis, Kniest dysplasia, Noonan syndrome and Trisomy 12p, which causes facial developmental defects and seizure disorders.