89 TANGIER DISEASE IN A BLACKMALE: AN UNUSUAL CLINICAL PRESENTATION

Abstract

Tangier disease is a rare autosomal recessive disorder characterized by very low plasma apolipoprotein (apo) A-I and high-density lipoprotein (HDL), by tissue accuiulation of cholesteryl esters, and by peripheral neuropathy. The disease has been describedin Caucasians only. We report on a case of Tangier disease in a black boy. He presented with symptoms of progressive lumbosacral plexopathy. Electromyography and nerve conduction studies, however, indicated an unusal form of diffuse sensorimotor polyneuropathy. Additicnally, deep interstitial keratitis of the cornea was diagnosed. This feature has not been previously reported in Tangier disease. Plasma cholesterol was reduced to 25ng/dl, HDL-cholesterol and apoA-I to <5mg/dl and 0.9mg/dl, respectively. Plasma apoB was 38mg/dl, plasma triglycerides 98mg/dl. Zonal ultracentrifugation showed the virtual absence of HDL, and reduced amounts of low-density lipoproteins enriched in triglycerides. The isoelectric points, molecular weights, and immunoreactivity of the major apoA-I isoproteins and of pro-apoA-I were normal. The amount of mature apoA-I isoproteins was greatly reduced. Apo C and apoE isoprotein patterns were normal. These findings support the view that Tangier disease is not due to a structural alteration of the apoA-I molecule and differ frcm a recent report on an electrophoretic variant of apoA-I in a Tangier patient (Bisgaier, C.L. et al., Biochim, Biophys Acta 1987:918:242.).