[Abetalipoproteinemia. Apropos of 2 cases]

The cases of two sisters with abetalipoproteinemia are reported. Both presented the complete clinical and biological features of the disease: ataxia, retinitis pigmentosa, lack of apolipoprotein B, chylomicrons, LDL and VLDL, reduced titers of serum cholesterol and triglycerides, acanthocytosis, very low levels of serum vitamin A and E. Abetalipoproteinemia is a rare autosomal inherited disease. It is usually revealed during early childhood by steatorrhea and failure to thrive; ataxia and retinitis pigmentosa appear later. The originality of these two cases stems from: 1) their late and fortuitous diagnosis: the first sister was investigated at the age of 42 after the discovery of a vitamin K induced coagulation disorder. The other sister was 39 when she was routinely examined as a family member; 2) the presence of constipation without any other suggestive digestive complaint. However, white discoloration of the duodenal mucosa seen at endoscopy and lipid droplets within the intestinal absorptive cells at biopsy were characteristic. Barium studies showed diffuse involvement of the small bowel which was displaced by an enlarged sigmoid. Treatment consists of administration of vitamin A and vitamin E which prevent or delay ocular and neurologic symptoms. Vitamin K is associated whenever necessary.