SMN1 and autoimmune hepatitis: According to the autoantibodies detected at diagnosis can be identified two subsets of AIH: type 1 autoimmune hepatitis (AIH-1), defined by the presence of anti-nuclear antibody (ANA) and/or anti-smooth muscle antibody (SMA), and type 2 autoimmune hepatitis (AIH-2) associated with positivity for anti-liver/kidney-microsomal-antibody-type-1 (anti-LKM-1) or anti-liver-cytosol-type-1 (anti-LC1) autoantibodies (3, 5).