Further evidence for NAFLD with a relative conservation of glucose metabolism can also be found in a small number of families with inherited gene mutations, such as familial hypobetalipoproteinemia (Amaro et al., 2010), lysosomal acid lipase deficiency (Reiner et al., 2014), adipose triglyceride lipase (ATGL) (Stefan et al., 2011), and gene mutations related to fatty acid oxidation (such as medium-chain acyl-CoA dehydrogenase deficiency and carnitine palmitoyl transferase-1) (Sun and Lazar, 2013). The gene discussed is PNPLA2; the disease is hyperinsulinemic hypoglycemia, familial, 4.