Identification of Weak D Type 1 in Rh Blood Group System and Discussion of Transfusion Strategy / 中国实验血液学杂志

OBJECTIVE@#To investigate the molecular mechanism of one patient with abnormal serological phenotype in RhD and discuss the transfusion strategy.@*METHODS@#The RhD variant sample was screened from a patient with IgM type anti-D antibody and further determined by three different sources of anti-D antibodies. Ten exons and the adjacent introns of the RHD gene were amplified, purified and sequenced. RhCE phenotypes and RHCE genotypes were detected.@*RESULTS@#The patient with Rh variant showed abnormal results of serological tests. The RHD gene sequence analysis showed that the RHD*01W.01 with a variation (c.809T>G, p.Val270Gly) in exon 6 of the RHD gene was found in the patient. The RhCE phenotype was CcEe. The genotyping results of RHCE were consistent with the serological typing results.@*CONCLUSION@#The Rh variant of the patient is RHD*01W.01, these findings indicate that RhD variants should be analyzed by molecular assays for the sake of safe transfusion.

Different Subtypes Caused by c.721C>T Substitution in the Exon 7 of ABO Gene / 中国实验血液学杂志

OBJECTIVE@#To analyze the different subtypes caused by c.721C>T substitution in the exon 7 of the ABO gene, and to investigate the related molecular mechanism of different antigens expression.@*METHODS@#ABO subtypes in 7 samples were identified by standard serological methods. The exons 6, 7, and adjacent intron of ABO gene were amplified by Polymerase Chain Reaction (PCR), and the PCR products were analyzed by direct DNA sequencing and cloning sequencing.@*RESULTS@#ABO subtypes phenotypes were A@*CONCLUSION@#c.721C>T substitution in the ABO gene causes p.Arg241Trp exchange resulting in the decreasing of GTA or GTB activities and weaker antigen expression. O.01.07 is a null allele which cannot form a functional catalytic enzyme has no effect on A

Study on the Identification of Samples Mistyped as O Phenotype and the Strategy of Safe Blood Transfusion / 中国实验血液学杂志

OBJECTIVE@#To investigate the indentification method of samples mistyped as O phenotype and to explore the precision transfusion strategy.@*METHODS@#The blood samples from donors and patients admitted in our center from 2018 to 2019 was collected. The samples with O phenotype suspected subtypes were further determined by tube test, adsorption-elution test, etc. Molecular testing was used to sequence the related blood type genes of the subjects.@*RESULTS@#Among 14 subjects misjudged as O, 11 different genotypes were identified, in which 3 blood donors were Ael02/O02, Bel03/O02, and one para-Bombay with B101/O02 (FUT1: h3h3; FUT2: Se@*CONCLUSION@#The phenotypes of Ael, Bel, Aw and para-Bombay subtypes are easily misjudged as type O. Molecular technology is helpful to identify the genotype of subtypes, and the corresponding transfusion strategies could be reasonably performed.

Application of RASSF1A to Noninvasive Fetal ABO Genotyping in Pregrnant Peripheral Plasma / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of noninvasive fetal ABO genotyping based on RASSF1A gene with circulating cell-free fetal DNA(cffDNA) from maternal plasma.</p><p><b>METHODS</b>DNA was extracted from the O group pregnant plasma, and the presence of cffDNA was confirmed by fetal DNA maker SRY and RASSF1A. B and non-O were detected by real-time PCR, and the genotyping results were evaluated by using the serologic tests for ABO phenotyping.</p><p><b>RESULTS</b>Among the samples of 20 cases, the SRY was found in 11 cases by detecteion, the detection results were consistent with sex of infants after delivery; the RASSF1A was amplified all in samples of other 9 cases after BstU1 cleavage, which confirmed existance of cffDNA. The ABO gene detection of cffDNA in plasma showed that out of 20 samples, both non O and B were amplified simultancously in 8 cases, suggesting the B blood group; the non O was amplified, but the B was not amplified only in 5 cases, suggesting A blood group, the non O and B both were not amplified in samples of 7 cases, suggesting O blood group. The above-mentioned detection results were consistent with new born ABO blood group by serological test.</p><p><b>CONCLUSION</b>The proposed protocol for the detection of fetal ABO based on RASSF1A gene by using fetal DNA from maternal plasma can be used for noninvasive prenatal diagnosis of fetal ABO blood group.</p>