A
Fish-Eye Disease family has been recently discovered in Bordeaux, being made up 3 homozygous and 3 heterozygous patients for a recessive hereditary anomaly of LCAT. The influence of the
enzyme on the plasma
lipoprotein 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 patient's LCAT gene with those which have been obtained in other FED patients as in patients with classic
LCAT deficiency allows to differenciate biochemically both pathologies. It allows too the differentiation between primary and secondary (
Tangier disease,
apo A-I deficiency, A-I and C-III
deficiency) LCAT deficiencies, which may be all associated with a
Corneal arcus. The profile of the lipidic parameters most often measured in plasma (Total
cholesterol, HDL-
cholesterol,
cholesterol esterification rate, lipidogramme,
apo A-I,
apo A-II, LCAT mass and activity) is practically pathognomonic of this affection and consequently authorizes its differential diagnosis. In spite of the striking deficiency of HDL as of their
atherogenesis preventing markers these patients do not show any sign of early cardio
vascular disease.