RHD Genotypes in a Chinese Cohort of Pregnant Women

Abstract

RHD variants in D¯ Chinese pregnant women arose difficulties in management during pregnancy. Therefore, this study aims to precisely manage D¯ pregnant women by evaluating the spectrum of RHD mutations in D¯ pregnant women and getting insight into the possible rare alleles of RHD. A total of 76 D¯ pregnant women were analyzed by performing polymerase chain reactions with sequence-specific primers (PCR-SSP), the 10 RHD exons Sanger sequencing, RHD zygosity detection, and mRNA sequencing (mRNA-seq). About 40% of alleles are variations of RHD, including RHD 1227A homozygous, RHD-CE(2-9)-D, et al. Therefore, we developed a molecular diagnostic strategy for Chinese women, and most D¯ pregnant women can be diagnosed with this simple decision tree. After RHD genotyping for D¯ pregnancy women, we eliminated at least 15% unnecessary ante- and postpartum injections of Rh immunoglobulin (RhIG). As the first pedigree study and the first functional analysis under physiological conditions, mRNA-seq revealed that c.336-1G>A mutation mainly led to the inclusion of the intron 2, which indirectly explained the D¯ phenotype in this family. We also developed a robust protocol for determining fetal RhD status from maternal plasma. All 31 fetuses were predicted as RhD positive and confirmed the RhD status after birth.

RHD*DNT (RHD*38) Showing D-Positive Reactivity on Rhesus D Typing and Forming Anti-D Antibody

“…Dear Editor, In the Rhesus (Rh) blood group system, D variant antigens are mainly due to a single-nucleotide variant or a RHD/RHCE hybrid gene and are classified into three groups: molecularly defined weak D phenotypes, molecularly defined partial D phenotypes, and DEL phenotypes [1]. Individuals having D variant antigens (except for Asian-type DEL and weak D types 1, 2, and 3) may have anti-D antibodies, which have clinical significance in transfusion or pregnancy [2]. Partial D may show variable serological reactivity.…”

“…Antibody screening using DiaCell I+II, Dia Positive (Bio-Rad, Glattbrugg, Switzerland) and antibody identification using ID-DiaPanel (Bio-Rad) with dithiothreitol-treated cells excluded anti-LW and confirmed anti-D. Real-time PCR and melting curve analysis revealed the presence of RHD , and PCR using sequence-specific primers (SSP) with BAGene RH-TYPE, Partial D-TYPE, and/or Weak D-TYPE SSP Kits (BAG Health Care GmbH, Lich, Germany) revealed partial D, suggesting RHD*DIIIc ( RHD*03.03 ) or other alleles harboring N512T [ 6 , 7 ]. Sanger sequencing of all 10 RHD exons and flanking regions of RHD confirmed RHD*DNT (method protocol available from the KRBP reference laboratory on request) [ 2 ].…”