Studies on the blood of a Dc(e) homozygote and her family.

It has been reported previously that genes that have been called Dc- represent a heterogeneous group and that some of them would better be described as Dc[e] and Dc(e). We have studied the blood of a black proposita and some of her family members and have concluded that she is homozygous for Dc(e). The form of Dc(e) present in this family makes all the Rh antigens of common occurrence for which we were able to test. In this respect, it differs markedly from another form of Dc(e), which is seen in individuals whose red cells lack a very common Rh antigen and who become immunized against that antigen. We suggest the term Dc(e)R17 for the gene present in the family studied; our results indicate that its products are: normal amounts of D, c, G, Hr0, and Rh29; reduced amounts of e and f; and markedly reduced amounts of hrS and hrB. The expression of some antigens encoded by Dc(e)R17 are quantitatively but not qualitatively different from the products of R0.