Acanthocytes and Disorders of Lipoprotein Metabolism

Abstract

Acanthocytosis and disordered lipoprotein metabolism are inextricably linked in medical history. The term “acanthocytosis” was itself coined a half-century ago to describe the dysmorphic erythrocytes seen in abetalipoproteinemia (ABL), a complex metabolic disorder that is characterised by fat malabsorption, atypical retinitis pigmentosa and spinocerebellar ataxia. ABL results from mutation in the gene encoding microsomal triglyceride transfer protein (MTP), which results in failure to synthesize apolipoprotein B-containing lipoproteins, producing very low plasma concentrations of cholesterol and triglycerides, and fat soluble vitamin deficiency. A phenotypically similar condition called homozygous hypobetalipoproteinemia results from mutation in the gene encoding apo B itself, and is clinically very similar to ABL. These conditions are both rare, with fewer than 1 affected subject in 100 000 in most populations. In addition, some neurological disorders with acanthocytosis are associated with depressed plasma lipoproteins.