Progressive Familial Intrahepatic Cholestasis, is an expanding group of autosomal recessive intrahepatic cholestatic disorders. Recently, Next Generation Sequencing allowed identifying new genes responsible for new specific disorders. Two biochemical phenotypes have been identified according to gamma-glutamyltransferase (GGT) activity. Mutations of the myosin 5B gene (MYO5B) are known to cause Microvillus Inclusion Disease. Recently, different mutations in MYO5B gene have been reported in patients with low-GGT cholestasis.