[THE PROPORTION OF ANTIHEMOPHILIC FACTORS: BIOLOGICAL AND GENETIC CORRELATION WAS DETERMINED ON 55 SUBJECTS].

On the basis of the genetic laws of transmission of the hemophilic gene, it was determined in 55 persons of both sexes from four hemophilic families that there were 14 non-hemophilics, six hemophilics, four possible hemophilics, six true carriers and 25 possible carriers of the hemophilic gene. Two methods were simultaneously used to assess the plasma content of antihemophilic factor. Excluding the known hemophilics, two of the four possible hemophilics had a low plasma content of factor VIII. Of the nine true or possible carriers, only one had an abnormal plasma level of factor VIII. Among the other carriers, three of four true carriers had a low level, as did six of 18 possible carriers. Using these methods, a satisfactory correlation was obtained between the genetic and biological findings.