We read with interest the recent article of Palfi et al. (2001) in which they identified anti-G anti-C without anti-D in 4/27 samples from pregnant women; none of the newborns needed postpartum treatment. Among a few other published cases, only Hadley et al. (1996) observed clinical significance of anti-G in a D negative baby. We would like to share our experience by presenting one case of a D negative, C positive newborn with moderate haemolytic disease of the newborn (HDN) delivered by a mother with anti-G anti-C; the clinical significance of anti-G, but not anti-C, was documented.A mother (group 0rr) delivered a group 0r H r baby with a positive direct antiglobulin test. The cord blood haemoglobin level was normal, but the bilirubin level was slightly elevated (3Á45 mg%), and rose on the second (13Á1 mg%) and the fourth day (20Á3 mg%) in spite of phototherapy. The child was discharged from the hospital on the seventh day in a good health without anaemia.An eluate prepared from the newborn's red cells was strongly positive by the indirect antiglobulin test with r H r, R 1 r, R 1 R 1 , weakly positive with R 0 r, R 2 r, R 2 R 2 , but negative with rr, r HH r cells.When examining the maternal serum (obtained just after delivery) with the panel of red cells by the indirect antiglobulin test, the enzyme (papain) and the polybrene test, we found antibodies to react with all but rr and r HH r cells, suggesting anti-D and anti-C. Differential adsorption/elution studies, using r H r and R 2 R 2 red cells, showed anti-C anti-G, but not anti-D. Moreover, the absence of the latter specificity was confirmed by negative reaction of maternal serum with R 2 r G(±) cells, which have D but not C and G antigens.The level and the functional activity of anti-C and anti-G were examined by indirect antiglobulin test (IAGT) and chemiluminescence test (CLT) (Hadley et al., 1991), respectively, using r H r red cells, such as the newborn's phenotype. For anti-C evaluation, anti-G was previously adsorbed from maternal serum using R 2 R 2 red cells; the titre was 8, the score À10 and the CLT result À1Á6%. The results obtained with nonadsorbed serum were 128, 67, and 18%, respectively; thus, the level and the activity of anti-G appeared to be much higher than that of anti-C. The results of CLT with anti-G were similar to the results observed with antibodies of other specificities in a mild/moderate HDN (Hadley et al., 1991;Zupan ska et al., 2001).Overall, our data allow us to say that the anti-G antibodies were responsible for moderate HDN. They confirm that such antibodies can be of clinical significance in pregnancy.