Two new JK silencing alleles identified by single molecule sequencing with 20-Kb long-reads.

Background: The Kidd blood group gene SLC14A1 (JK) accounts for approximately 20 Kb from initiation codon to stop codon in the genome. In genomic DNA analysis using Sanger sequencing or short-read-based next generation sequencing, it is difficult to determine the cis or trans positions of single nucleotide variations (SNVs), which are occasionally more than 1 Kb away from each other. We aimed to determine the complete nucleotide sequence of a 20-Kb genomic DNA amplicon to characterize the JK allelic variants associated with Kidd antigen silencing in a blood donor.

Genetic background of anti-Xg producers in Japanese blood donors.

Background And Objectives: The Xg blood group is composed of two antigens, Xg (XG1) and CD99 (XG2 and MIC2). The XG and CD99 are homologous genes located on pseudoautosomal region 1 of the X and Y chromosomes. The expressions of Xg and CD99 are co-regulated by a single nucleotide polymorphism (rs311103) in the GATA-1 binding region.

Constructing Soluble Anthracene-Based Blue Emitters Free of Electrically Inert Alkyl Chains for Efficient Evaporation- and Solution-Based OLEDs.

Anthracene derivatives are one of the most promising blue emitters employed in organic light-emitting devices (OLEDs) because of their electrochemical and thermal stabilities. However, their high crystallinity owing to their large π-planar structures severely impedes the progress in the development of solution-based systems. In this work, we developed two types of highly soluble multifunctional anthracene derivatives terminated with ortho-biphenyl and triphenylamine moieties and showed high solubility in general organic solvents such as toluene, tetrahydrofuran, and cyclohexanone at high concentrations (>10 mg mL ), and showed blue emission with a peak wavelength of ∼465 nm and a high photoluminescence quantum yield that ranges up to 81 %.

Reduction of blood group A antigen on erythrocytes in a patient with myelodysplastic syndrome harboring somatic mutations in RUNX1 and GATA2.

Background: Reduction of blood group ABO antigens on red blood cells (RBCs) is well known in patients with leukemias, and this reduction of ABO expression is strongly associated with DNA methylation of the ABO promoter. Previously, we reported a two-nucleotide deletion in RUNX1 encoding an abnormally elongated protein lacking the trans-activation domain in a patient with myelodysplastic syndrome (MDS) showing A-antigen loss on RBCs. This prompted us to investigate the underlying mechanism responsible for A-antigen reduction on RBCs in another patient with MDS.

Asymmetric Spirobiacridine-based Delayed Fluorescence Emitters for High-performance Organic Light-Emitting Devices.

Invited for the cover of this issue is Hisahiro Sasabe, Junji Kido and co-workers at Yamagata University in Japan. This image depicts that the chemical structure of the acceptor is one of the most important keys to maximize the potential of triazine/acridine-based thermally activated delayed fluorescence (TADF) emitters realizing high external quantum efficiency (EQE) of over 30%. Read the full text of the article at 10.

Asymmetric Spirobiacridine-based Delayed Fluorescence Emitters for High-performance Organic Light-Emitting Devices.

Recently, researchers have focused on thermally activated delayed fluorescence (TADF) for efficient future lighting and displays. Among TADF emitters, a combination of triazine and acridine is a promising candidate for realizing high-efficiency organic light-emitting devices (OLEDs). However, simultaneous development of perfect horizontal orientation (Θ=100 %) and an external quantum efficiency (EQE) of over 40 % is still challenging.

Novel hybrid genes and a splice site mutation encoding the St antigen among Japanese blood donors.

Background: The low-incidence antigen St of the MNS system is usually associated with the GP(B-A) hybrid molecule, which carries the 'N' antigen at the N terminus. The GP(A-A) molecule with trypsin-resistant M antigen has been found in a few St(a+) individuals.

Materials And Methods: Among Japanese blood donors, we screened 24 292 individuals for the presence of St(a+) with trypsin-resistant 'N' antigen and 193 009 individuals for the presence of St(a+) with trypsin-resistant M antigen.

A new antigen SUMI carried on glycophorin A encoded by the GYPA*M with c.91A>C (p.Thr31Pro) belongs to the MNS blood group system.

Background: MNS is one of the highly polymorphic blood groups comprising many antigens generated by genomic recombination among the GYPA, GYPB, and GYPE genes as well as by single-nucleotide changes. We report a patient with red blood cell (RBC) antibody against an unknown low-frequency antigen, tentatively named SUMI, and investigated its carrier molecule and causal gene.

Study Design And Methods: Standard serologic tests, including enzyme tests, were performed.

An unusual variant glycophorin expressing protease-resistant M antigen encoded by the GYPB-E(2-4)-B hybrid gene.

Background And Objectives: MNS is a highly polymorphic blood group comprising 49 antigens recognized by International Society of Blood Transfusion, some of which may have been generated by genomic recombination among the closely linked genes GYPA, GYPB and GYPE. The GYPE gene has an almost identical sequence to GYPA*01 allele in exon 2 (99% homology), which accounts for M antigen. We investigated an unusual glycophorin molecule with protease-resistant M antigen.

RUNX1 mutation in a patient with myelodysplastic syndrome and decreased erythrocyte expression of blood group A antigen.

Background: Loss of blood group ABO antigens on red blood cells (RBCs) is well known in patients with leukemias, and such decreased ABO expression has been reported to be strongly associated with hypermethylation of the ABO promoter. We investigated the underlying mechanism responsible for A-antigen reduction on RBCs in a patient with myelodysplastic syndrome.

Study Design And Methods: Genetic analysis of ABO was performed by PCR and sequencing using peripheral blood.

Anemic Disease of the Newborn With Little Increase in Hemolysis and Erythropoiesis Due to Maternal Anti-Jr: A Case Study and Review of the Literature.

The severity of the hemolytic disease of the fetus and newborn (HDFN) due to Jr mismatch ranges from no symptoms to severe anemia that requires intrauterine and exchange transfusions. We encountered a newborn, born to a healthy mother having anti-Jr at 38 weeks of pregnancy, who had moderate anemia, a positive direct antiglobulin test (DAT) result, no increased erythropoiesis, and no jaundice at birth. Flow cytometry revealed that the Jr antigen of red cells in the infant was nearly negative at birth, biphasic at 5 weeks, and lowly expressed at 7 months of life.

Integrative genome analysis identified the KANNO blood group antigen as prion protein.

Background: Anti-KANNO, a broadly reactive RBC alloantibody, is found among some Japanese pregnant women, but the genetic basis of the corresponding antigen remains unclear.

Study Design And Methods: We integrated a statistical approach to identify the coding gene for KANNO antigen by conducting a genome-wide association study (GWAS) on four KANNO-negative individuals and 415 healthy Japanese. We also applied whole-exome sequencing to them and performed a replication study to confirm the identified genome variation using independent 14 KANNO-negative individuals.

Rh phenotype caused by a novel RHAG mutation, c.945+1G>A, in the Japanese population.

Background: The Rh complex contributes to cell membrane structural integrity of erythrocytes. Rh syndrome is characterized by the absence of the Rh antigen on the erythrocyte membrane, resulting in chronic hemolytic anemia. We recently came across 3 Rh phenotype probands within two families with the same novel RHAG mutation in the Japanese population.

Application of immortalized human erythroid progenitor cell line in serologic tests to detect red blood cell alloantibodies.

Background: Antibody screening in pretransfusion tests is necessary to avoid critical complications of blood transfusion. Although red blood cells (RBCs) expressing relevant alloantigen(s) have been used for serologic antibody screening, little attention has been given to the use of cell lines, in which blood group antigen gene(s) are transduced, as reagent RBCs for antibody screening.

Study Design And Methods: The use of an erythroid progenitor cell line for serologic tests was studied.

Silent KEL alleles identified from Japanese individuals with the K phenotype.

Background And Objective: The rare K phenotype lacks all 36 antigens in the Kell blood system. The molecular basis of the K phenotype has been investigated, and more than 40 silent KEL alleles are reported by many investigators. The majority of silent alleles are the KEL*02 background.

Mutations of the KLF1 gene detected in Japanese with the In(Lu) phenotype.

Background: In(Lu) is characterized by a reduced expression of antigens in the Lutheran blood group system as well as other blood group antigens. Mutations of the erythroid transcription factor, KLF1, have been reported to cause the In(Lu) phenotype, and we investigated Japanese In(Lu) to estimate the prevalence of the phenotype and KLF1 polymorphism.

Study Design And Methods: Blood samples were screened by monoclonal anti-CD44 and the In(Lu) phenotype was confirmed by tube tests including adsorption and elution tests using anti-Lu and anti-Lu .

Prevalence of RHD alleles in Japanese individuals with weak D phenotype: Identification of 20 new RHD alleles.

We identified 46 different RHD alleles from 226 Japanese individuals with weak D phenotype, 26 of which had been previously described and 20 that were novel. Among these weak D individuals, the alleles with c.960G>A, c.

Weak D alleles in Japanese: a c.960G>A silent mutation in exon 7 of the RHD gene that affects D expression.

Background And Objectives: The molecular basis of the weak D phenotype has been investigated for many years, and more than 80 different alleles producing weak D phenotypes have been identified. Most alleles producing weak D phenotypes have a single missense mutation in exons corresponding to a transmembrane domain of the RhD polypeptide. We report here RHD alleles with single nucleotide mutations in Japanese accounting for weak expression of D antigen.

Molecular basis for D- Japanese: identification of novel DEL and D- alleles.

Background And Objectives: The occurrence of D- is approximately 0.5% in Japanese, but DEL in apparently D- individuals is relatively common compared with that in Caucasian populations. On the basis of molecular genetics, we examined D- Japanese blood donors.

A novel DO null allele with a c.268C>T (p.Gln90Stop) mutation in Japanese.

The Dombrock blood group system consists of two antithetical antigens, Do(a) (DO1) and Do(b) (DO2), and seven high-prevalence antigens, Gy(a) (DO3), Hy (DO4), Jo(a) (DO5), DOYA (DO6), DOMR (DO7), DOLG (DO8) and DOLC (DO9). Do(a) /Do(b) polymorphism is associated with c.793A>G (p.

A new ABCG2 null allele with a 27-kb deletion including the promoter region causing the Jr(a-) phenotype.

Background: The high-prevalence antigen Jr(a) is carried on the ATP-binding cassette transporter ABCG2. The ABCG2 gene consists of 16 exons and its translation start codon is located on the second exon. Although the occurrence of the Jr(a-) phenotype is rare, several ABCG2 null alleles have been reported.

Production of human monoclonal anti-Jk3, recognising an epitope including the Jk(a) /Jk(b) polymorphic site of the Kidd glycoprotein.

Background And Objectives: The Kidd blood group system consists of polymorphic antigens, Jk(a) (JK1) and Jk(b) (JK2), and a high-incidence antigen, Jk3. Anti-Jk3 is often observed in immunised Jk(a-b-) individuals. In this study, we aimed to establish a human hybridoma cell line secreting monoclonal anti-Jk3 (HIRO-294).

JK null alleles identified from Japanese individuals with Jk(a−b−) phenotype.

The Kidd blood group system consists of three common phenotypes: Jk(a+b−), Jk(a−b+) and Jk(a+b+), and one rare phenotype, Jk(a−b−). Jka/Jkb polymorphism is associated with c.838G>A (p.

Presence of nucleotide substitutions in transcriptional regulatory elements such as the erythroid cell-specific enhancer-like element and the ABO promoter in individuals with phenotypes A3 and B3, respectively.

Background And Objectives: An erythroid cell-specific regulatory element, referred to as the +5.8-kb site, has been identified in the first intron of the human ABO blood group gene. Subsequent studies have revealed involvement of deletion or mutation at the site in phenotypes Am , Bm and ABm .