A Bioinformatically Initiated Approach to Evaluate GATA1 Regulatory Regions in Samples with Weak D, Del, or D- Phenotypes Despite Normal Exons.

Introduction: With over 360 blood group antigens in systems recognized, there are antigens, such as RhD, which demonstrate a quantitative reduction in antigen expression due to nucleotide variants in the non-coding region of the gene that result in aberrant splicing or a regulatory mechanism. This study aimed to evaluate bioinformatically predicted GATA1-binding regulatory motifs in the gene for samples presenting with weak or apparently negative RhD antigen expression but showing normal exons.

Methods: Publicly available open chromatin region data were overlayed with GATA1 motif candidates in .

Impact of transcription factors KLF1 and GATA1 on red blood cell antigen expression: a review.

KLF transcription factor 1 (KLF1) and GATA binding protein 1 (GATA1) are transcription factors (TFs) that initiate and regulate transcription of the genes involved in erythropoiesis. These TFs possess DNA-binding domains that recognize specific nucleotide sequences in genes, to which they bind and regulate transcription. Variants in the genes that encode either KLF1 or GATA1 can result in a range of hematologic phenotypes-from benign to severe forms of thrombocytopenia and anemia; they can also weaken the expression of blood group antigens.

A cold case of hemolytic disease of the fetus and newborn resolved by genomic sequencing and population studies to define a new antigen in the Rh system.

Background: We report an obstetric case involving an RhD-positive woman who had developed a red blood cell (RBC) antibody that was not detected until after delivery of a newborn, who presented with a positive direct antiglobulin test result. Immunohematology studies suggested that the maternal antibody was directed against a low-prevalence antigen on the paternal and newborn RBCs.

Results: Comprehensive blood group profiling by targeted exome sequencing revealed a novel nonsynonymous single nucleotide variant (SNV) RHCE c.

Feasibility for non-invasive prenatal fetal blood group and platelet genotyping by massively parallel sequencing: A single test system for multiple atypical red cell, platelet and quality control markers.

Non-invasive prenatal tests (NIPT) to predict fetal red cell or platelet antigen status for alloimmunised women are provided for select antigens. This study reports on massively parallel sequencing (MPS) using a red cell and platelet probe panel targeting multiple nucleotide variants, plus individual identification single nucleotide polymorphisms (IISNPs). Maternal blood samples were provided from 33 alloimmunised cases, including seven with two red cell antibodies.

Recurrent pregnancy loss in a patient with anti-Rh17.

Background: Rh is one of the most important blood group systems in transfusion medicine. The two homologous genes RHD and RHCE are located on chromosome 1p36.11 and encode for RhD and RhCE proteins, respectively.

Fatal haemolytic transfusion reaction due to anti-En and identification of a novel GYPA c.295delG variant in a Thai family.

Background And Objectives: High-frequency antigen En (MNS 28) is expressed on glycophorin A (GPA). En(a-) individuals can form anti-En when exposed to GPA. A Thai patient formed an antibody that reacted against all reagent red blood cells (RBCs).

Hemolytic disease of the fetus and newborn caused by anti-s antibody in a GP.Mur/Mur Thai mother and review of the prevalence of s in Thai blood donors.

Background: Low-prevalence antigen s (MNS23) is encoded by GYPB c.173C > G. Hemolytic disease of the fetus and newborn (HDFN) due to anti-s is rare.

A new high-prevalence LW antigen detected by an antibody in an Indigenous Australian homozygous for LW*A c.309C>A variant.

Background And Objectives: The LW gene encodes the LW glycoprotein that carries the antigens of the LW blood group system. LW antigens are distinct from D antigen, however, they are phenotypically related and anti-LW antibodies are often mistaken as anti-D. An antibody was detected in an Australian patient of Aboriginal descent who consistently typed as LW(a+b-).

Frequency of Mi (MNS7) and Classification of Mi-Positive Hybrid Glycophorins in an Australian Blood Donor Population.

Background: MNS blood group system genes and share a high degree of sequence homology and gene structure. Homologous exchanges between and form hybrid genes encoding hybrid glycophorins GP(A-B-A) and GP(B-A-B). Over 20 hybrid glycophorins have been characterised.

Genotyping analysis of MNS blood group GP(B-A-B) hybrid glycophorins in the Chinese Southern Han population using a high-resolution melting assay.

Background: MNS hybrid GP(B-A-B) glycophorins are more commonly found in Southeast Asians and alloantibodies to antigens they carry are clinically significant. Detection of hybrid glycophorins by serologic techniques is limited due to lack of commercial reagents. In this study, a genotyping method for GP(B-A-B) hybrid glycophorins based on high-resolution melting (HRM) analysis was applied for genotyping analysis in the Chinese Southern Han population.

A DEL phenotype attributed to RHD Exon 9 sequence deletion: slipped-strand mispairing and blood group polymorphisms.

Background: The RhD blood group antigen is extremely polymorphic and the DEL phenotype represents one such class of polymorphisms. The DEL phenotype prevalent in East Asian populations arises from a synonymous substitution defined as RHD*1227A. However, initially, based on genomic and cDNA studies, the genetic basis for a DEL phenotype in Taiwan was attributed to a deletion of RHD Exon 9 that was never verified at the genomic level by any other independent group.

Targeted exome sequencing defines novel and rare variants in complex blood group serology cases for a red blood cell reference laboratory setting.

Background: We previously demonstrated that targeted exome sequencing accurately defined blood group genotypes for reference panel samples characterized by serology and single-nucleotide polymorphism (SNP) genotyping. Here we investigate the application of this approach to resolve problematic serology and SNP-typing cases.

Study Design And Methods: The TruSight One sequencing panel and MiSeq platform was used for sequencing.

Non-invasive fetal RHD genotyping for RhD negative women stratified into RHD gene deletion or variant groups: comparative accuracy using two blood collection tube types.

Non-invasive fetal RHD genotyping in Australia to reduce anti-D usage will need to accommodate both prolonged sample transport times and a diverse population demographic harbouring a range of RHD blood group gene variants. We compared RHD genotyping accuracy using two blood sample collection tube types for RhD negative women stratified into deleted RHD gene haplotype and RHD gene variant cohorts. Maternal blood samples were collected into EDTA and cell-free (cf)DNA stabilising (BCT) tubes from two sites, one interstate.

Anti-D in a mother, hemizygous for the variant RHD*DNB gene, associated with hemolytic disease of the fetus and newborn.

Background: Individuals with the partial D phenotype when exposed to D+ red blood cells (RBCs) carrying the epitopes they lack may develop anti-D specific for the missing epitopes. DNB is the most common partial D in Caucasians and the clinical significance for anti-D in these individuals is unknown.

Study Design And Methods: This article describes the serologic genotyping results and clinical manifestations in two group D+ babies of a mother presenting as group O, D+ with alloanti-D.

Evaluation of targeted exome sequencing for 28 protein-based blood group systems, including the homologous gene systems, for blood group genotyping.

Background: Blood group single nucleotide polymorphism genotyping probes for a limited range of polymorphisms. This study investigated whether massively parallel sequencing (also known as next-generation sequencing), with a targeted exome strategy, provides an extended blood group genotype and the extent to which massively parallel sequencing correctly genotypes in homologous gene systems, such as RH and MNS.

Study Design And Methods: Donor samples (n = 28) that were extensively phenotyped and genotyped using single nucleotide polymorphism typing, were analyzed using the TruSight One Sequencing Panel and MiSeq platform.

Genotyping for Glycophorin GYP(B-A-B) Hybrid Genes Using a Single Nucleotide Polymorphism-Based Algorithm by Matrix-Assisted Laser Desorption/Ionisation, Time-of-Flight Mass Spectrometry.

The genetic basis for five GP(B-A-B) MNS system hybrid glycophorin blood group antigens results from rearrangement between the homologous GYPA and GYPB genes. Each hybrid glycophorin displays a characteristic profile of antigens. Currently, no commercial serological reagents are currently available to serologically type for these antigens.

A D+ blood donor with a novel RHD*D-CE(5-6)-D gene variant exhibits the low-frequency antigen RH23 (D(W) ) characteristic of the partial DVa phenotype.

Background: Blood donors whose red blood cells (RBCs) exhibit a partial RhD phenotype, lacking some D epitopes, present as D+ in routine screening. Such phenotypes can exhibit low-frequency antigens (LFAs) of clinical significance. The aim of this study was to describe the serologic and genetic profile for a blood donor with an apparent D+ phenotype carrying a variant RHD gene where D Exons 5 and 6 are replaced by RHCE Exon (5-6).

Identification of six new RHCE variant alleles in individuals of diverse racial origin.

Background: The introduction of molecular methods into routine blood typing is prompting the identification of new blood group alleles. Discrepancies between the results of genotyping and serology or chance events uncovered during genotyping prompted additional investigations, which revealed six new RHCE variant alleles.

Study Design And Methods: Samples from eight blood donors, two patients (one prenatal), and a patient's relative, all of diverse racial origin, were analyzed by standard serology methods, targeted genotyping arrays, DNA sequencing, and allele-specific polymerase chain reaction.

Molecular typing for the Indian blood group associated 252G>C single nucleotide polymorphism in a selected cohort of Australian blood donors.

Background: The Indian blood group antigens, In(a) and In(b), are clinically significant in transfusion medicine. However, antisera to type these antigens are difficult to obtain. The In(b) antigen is a high frequency antigen present in all populations, while the frequency of the antithetical In(a) ranges from 0.