Blood Group: Kidd
Common: Rare in most populations, found in 0.9% Polynesians
Causes HDN: Yes
Anti-Jk3 is made by individuals with the rare JK-null phenotype. This is Jk (a-b-). This single antibody recognizes both Jka and Jkb antigens. Anti-Jk3 can cause HDN in pregnancy and will hemolyse donor blood in a blood transfusion.  In two reported cases of anti-Jk3 [2, 3], the infants were treated with phototherapy. No transfusions were necessary.