Human albumin genetic variants: an attempt at a classification of European allotypes.

The relative mobility of albumin and proalbumin genetic variants was estimated by means of cellulose acetate electrophoresis performed with three buffer systems at different pH (8.6, 5.0, and 6.9) after addition of a reference protein and dilution of sera. Numerous experiments using samples of reference variants corroborated the accuracy and reproducibility of this technique. The estimation of the variants' relative mobility at three pH allowed us to distinguish three fast-moving variants (Gent, Vanves, and Reading) and five slow-moving variants (Sondrio, Roma, Christchurch, Lille, and B) in the French population. The frequency of alloalbuminemia in this population is .0004 and is characterized by the high occurrence of albumin B and of the two proalbumin variants, Christchurch and Lille. In order to classify the variants of European origin, the methodology that we developed, owing to its more resolutive possibilities, should be employed as a first step in their identification until establishment of a structural nomenclature making mention of the amino acid substitution characterizing each variant.