ATP8B1 and metabolic syndrome: In addition to the abovementioned phenotypes, and in contrast to other forms of cholestasis, low/normal γ-glutamyl transpeptidase PFIC1 patients present with dyslipidemia, characterized by hypertriglyceridemia, low high-density lipoprotein and low plasma cholesterol levels, of which the etiology is not understood [13,14,15].