SMN1 and autoimmune hepatitis: AIH can be classified into two categories based on the type of serum autoantibodies present: one type is positive for liver kidney microsomal antibody type 1 (LKM-1) (type 2 AIH, AIH-2) and another type is positive for smooth muscle antibody (SMA) and/or antinuclear antibody (ANA) (type 1 AIH, AIH-1) [25].