The positivity of serum antinuclear antibodies (ANA) and/or smooth muscle antibodies (SMA)/anti-actin antibodies are characteristic of the adult form of the disease, named type 1 AIH, while the positivity of antibodies to liver-kidney microsomes (LKM) is characteristic of the pediatric form of the disease, called type 2 AIH [4,5,6]. The gene discussed is SMN1; the disease is autoimmune hepatitis.