Molecular determination of RHD zygosity: predicting risk of hemolytic disease of the fetus and newborn related to anti-D.

Objective: Development of an accurate molecular method for paternal RHD zygosity to predict risk to a fetus for hemolytic disease of the fetus and newborn (HDFN) related to anti-D.

Methods: Quantitative fluorescence polymerase chain reaction (QF-PCR) was used to detect RHD exons 5 and 7, using RHCE exon 7 as an internal control. The genotype and zygosity were determined from the peak area ratios of RHD exon 5 or 7 to RHCE exon 7.