The r' gene is overrepresented in hrB-negative individuals

A screening program was implemented to identify hrB- donors. D- C+, D-C-, and D+C- samples from African-American donors were typed with multiple examples of anti-hrB and anti-hrB-like, and one example each of anti-V and anti-VS. Of 75 D-C+ donors, 4 (5%) typed as hrB-, and 14 others had weak or variable expression of hrB. Of these 18 individuals, 15 were V-VS+, and 3 were V+VS+. No hrB- sample was found in 90 C- donors, 26 of whom were V+VS+, and 1 was V-VS+. A review of our records of 44 hrB- patients and donors studied earlier revealed that at least 12, and possibly as many as 30, carried r or rs. All hrB- donors found in our screening program had D-C+VS+ RBCs, indicating an overrepresentation of r. Our record review also showed that the presence of r and rs more often results in hrB- RBCs, and that the most effective way to screen for hrB- donors is to type African Americans who have D-C+ RBCs.