Two AIH types have been defined according to the autoantibody profile: type 1 (AIH-1) is positive for anti-nuclear antibody (ANA) and/or smooth muscle antibody (SMA), and type 2 (AIH-2) is positive for anti-liver kidney microsomal type 1 (anti-LKM1) antibody [2]. This evidence concerns the gene SMN1 and autoimmune hepatitis.