The Rh o Variant — D u

In a survey of 18,365 bloods for the incidence of the D u factor, in a population comprised approximately of 72 per cent Caucasoids, 15 per cent Negroids, 10 per cent Mexicans and 3 per cent Orientals, 78 D u bloods were found of which seven were type ccD u ee. Of the latter, five came from Negroids and two from Caucasoids; the frequency among the two populations approximates respectively one in 6,000 and one in 500. In the general population of this region it is one in 2,500. The degree of reactivity of the type ccD u ee found in this study was that of the “low grade” variety. However, from the remaining 71 “low grade” D u bloods, substantially weaker examples were found among type CcD u ee and ccD u Ee. The indirect antiglobulin and ficinized cell method readily detected type ccD u ee; however, among the weaker variants, the antiglobulin method gave the more consistent results. It is concluded, therefore, that type ccD u ee does occur in this area with a frequency that is considered significant and that its detection rests on the antiglobulin or other equally sensitive methods.