[Application of bidimensional electrophoresis in the determination of genetic variants]

Study of the polymorphism of human plasma proteins presents a major advantage in clinical biology to discover abnormal or rare forms, associated with risks or involved with well-specified pathological conditions. If this polymorphism corresponds to structural differences causing a variation of the isoelectric point (Ip) or the molecular weight, it is easily visualized with bidimensional electrophoresis, starting with a few microliters of plasma. On a single mapping per patient, we were able to establish the frequency of various isoforms of Gc globulin, transferrin, haptoglobin, alpha-1-antitrypsin and apolipoproteins E as well as A-IV, in a Lorraine population consulting for a health check-up. This method has already enabled us to demonstrate the effect of polymorphic apolipoproteins on the cholesterol and triglycerides level: patients carrying the epsilon 2 allele of the Apo E, have a mean cholesterol level which is lower than that of the carriers of allele epsilon 3. Patients carrying allele epsilon 4 have the highest mean cholesterol level.