Non-alcoholic fatty liver disease (NAFLD) is a world-wide problem with a global prevalence estimated at 1.5 billion people. It is characterised by significant diversity and phenotypic heterogeneity. Morbidity rates are estimated at 20% to 30% in Western adults, increasing to 90% in patients who are morbidly obese or diabetic. Risk factors in non-obese NAFLD patients are of especial practical and theoretical importance. Cholesterol Ester Storage Disease (CESD) is an autosomal recessive chronic disease of variable phenotype, caused by a deficiency in lysosomal acid lipase (LAL) and characterized by accumulation of fat in tissues and organs. Hepatic accumulation of fat in this disorder can cause hepatomegaly with varying degrees of damage varying from steatosis to fibrosis, elevated aminotransaminases, and isolated splenomegaly. Since the contribution of LAL deficiency to non-obese NAFLD is poorly understood, the investigators propose to evaluating the association between NAFLD and LAL deficiency in a prospective study in our population.