Marked hyper-HDL2-cholesterolemia associated with premature corneal opacity. A case report

We report here a peculiar case with premature corneal opacity and extremely high levels of HDL cholesterol in serum. The patient is a 54-year-old man who was first noticed to have marked corneal opacities at age 19. His serum HDL cholesterol level was elevated to the level of 135-160 mg/dl, while total serum cholesterol and triglyceride concentrations were 254 mg/dl and 56 mg/dl, respectively. Serum apoprotein A-I and E levels analyzed by single radial immunodiffusion method were elevated in the case. Serum lipoprotein fractions isolated by preparative ultracentrifugation revealed that increased levels of HDL cholesterol were accounted for solely by the HDL2 fraction. HDL2 of the patient contained relatively higher amounts of apoprotein E than normal control HDL2. Elution profiles of lipoproteins in high performance liquid chromatography revealed that HDL2 particles from the patient were larger in size than those from normal controls. These characteristics of HDL are in part similar to those of HDLC which appears in experimental animals after cholesterol feeding. Such abnormalities in HDL2 fractions associated with premature corneal opacity have not been reported so far and appear to constitute a new disease entity.