RESUMEN
Fatty liver disease is now recognized as a major health burden, due to the greater number of cases that are being diagnosed. This trend could partly be explained by the increased use of liver ultrasonography in asymptomatic patients for various reasons, mainly persistent transaminase elevation. The most commonly reported risk factors associated with fatty liver disease are chronic alcohol intake, obesity, type 2 diabetes mellitus, hyperlipidemia, and some drugs. When these factors have been ruled out in a patient with a fatty liver, less frequent causes such as certain inherited metabolic disorders should be considered. Familial hypobetalipoproteinemia is characterized by an alteration of apolipoprotein B (apo B) synthesis, leading to the secretion of truncated forms of the protein, which in turn leads to a marked reduction in excretion of very low-density lipoproteins from the liver and consequently to lipid deposits, especially triglycerides, in the hepatocytes. We report the case of a 23-year-old man who met the diagnostic criteria for heterozygous familial hypobetalipoproteinemia. He presented with mild transaminase elevation and fatty liver. Total cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol and apo B were below normal limits, while levels of high-density lipoprotein cholesterol were normal. Lipid profile determination and liver ultrasonography of first and second-degree relatives were also performed. Molecular studies of the index case revealed an unaffected apo B gene.
