ARCUS-JUVENILIS AND LECITHIN - CHOLESTERO L ACYLTRANSFERASE FUNCTIONSWITH REGARD TO A FAMILIAL CASE OF FISH-EYE-DISEASE

A Fish-Eye Disease family has been recently discovered in Bordeaux, be ing made up 3 homozygous and 3 heterozygous patients for a recessive h ereditary anomaly of LCAT. The influence of the enzyme on the plasma l ipoprotein composition and its role in cholesterol efflux explain, at least for a part, the pathophysiology of the lipidic corneal clouding which is the single symptom in the homozygous patients. The comparison of the molecular biology data resulting from the analysis of the pati ent's LCAT gene with those which have been obtained in other FED patie nts as in patients with classic LCAT deficiency allows to differenciat e biochemically both pathologies. It allows too the differentiation be tween primary and secondary (Tangier disease, apo A-I deficiency, A-I and C-III deficiency) LCAT deficiencies, which may be all associated w ith a Corneal arcus. The profile of the lipidic parameters most often measured in plasma (Total cholesterol, HDL-cholesterol, cholesterol es terification rate, lipidogramme, apo A-I, apo A-II, LCAT mass and acti vity) is practically pathognomonic of this affection and consequently authorizes its differential diagnosis. In spite of the striking defici ency of HDL as of their atherogenesis preventing markers these patient s do not show any sign of early cardio vascular disease.