Distribution of ABO, Rhesus D and Subgroups of ABO among Blood Donors in Sokoto, North Western Nigeria

ABO, Rhesus D and subgroups of ABO are highly immunogenic and are the common cause of antibody production in mismatched blood transfusions, haemolytic transfusion reaction and maternal alloimmunization. The aim of this study was to determine the occurrence of ABO, Rh D and subgroups of ABO among blood donors attending Specialist Hospital Sokoto, Nigeria. ABO, Rhesus D and subgroups of ABO antigen status of 176 blood donors with mean age of 30.44 � 8.210 years attending Specialist Hospital Sokoto were determined using tile method for ABO and Rh D and conventional tube method for anti- A1, anti- H reagents for ABO subgroups respectively. Among the 176 subjects tested, blood group O+ was the most frequent group with 93 (52.8%), 39 (22.2%) were blood group B+, 37(21.0%) were blood group A+, 5 (2.8%) were blood group AB+, 2 (1.1%) were blood group O-. No data was obtained for A-, B- and AB- blood groups. Out of 37 A blood groups obtained, 31 (83.8%) had A1 antigens and 6 (16.2%) had A2 antigens. Out of the 5 AB blood groups, all had A1B antigens. The study also shows that there was statistically significant difference between blood group A and ethnic groups (Hausa, Fulani and Yoruba) (p<0.05). Blood group O was found to be the most frequent followed by B, A and AB except among Hausa which revealed a pattern of O> A> B> AB. ABO, subgroups shows majority had A1 followed by A2 and A1B respectively.

Six Years' Experience Performing ABO Genotyping by PCR-direct Sequencing / 대한수혈학회지

BACKGROUND: ABO genotyping is essential for resolving ABO grouping discrepancy and for determinating ABO subgroups. Most clinical samples, including suspected inherited subgroups and acquired variant phenotypes, can be determined by PCR-sequencing of exons 6 and 7 in the ABO gene. Here, we describe our six years' experience performing ABO genotyping by PCR-direct sequencing. METHODS: We conducted a retrospective investigation of serological and genotypical data from 205 samples (158 patients and 47 of their family members) of patients who were referred to the Molecular Genetics Laboratory at Chonnam National University Hwasun Hospital for ABO genotyping between January 2007 and July 2012. ABO genotyping was performed on all samples with PCR-direct sequencing of exons 6 and 7 in the ABO gene; the standard serologic tests were also performed. RESULTS: The frequency of phenotypes consistent with their genotypes was 70.8% (112/158 cases) and the A2B3 phenotype with the cis-AB01 allele was the most common (31.0%, 49 cases) among them. The frequency of phenotypes inconsistent with their genotypes was 29.1% (46/158 cases) and the A1B3 phenotype was the most frequently recovered case (5.1%, 8 cases). Family study showed differential phenotype expression depending on the co-inherited ABO allele in five families with the B306, cis-AB01, Ael02, Aw14, or B305 allele and also showed a typical inheritance of a chimera with A102/B101/O04. CONCLUSION: We propose that ABO genotyping using PCR-direct sequencing is useful for the resolution of ABO discrepancies and for the investigation of ABO subgroups based on six years' experience. In addition, family study for analysis of phenotypic patterns of ABO subgroups is also crucial to ABO genotyping.

Six Years' Experience Performing ABO Genotyping by PCR-direct Sequencing / 대한수혈학회지

BACKGROUND: ABO genotyping is essential for resolving ABO grouping discrepancy and for determinating ABO subgroups. Most clinical samples, including suspected inherited subgroups and acquired variant phenotypes, can be determined by PCR-sequencing of exons 6 and 7 in the ABO gene. Here, we describe our six years' experience performing ABO genotyping by PCR-direct sequencing. METHODS: We conducted a retrospective investigation of serological and genotypical data from 205 samples (158 patients and 47 of their family members) of patients who were referred to the Molecular Genetics Laboratory at Chonnam National University Hwasun Hospital for ABO genotyping between January 2007 and July 2012. ABO genotyping was performed on all samples with PCR-direct sequencing of exons 6 and 7 in the ABO gene; the standard serologic tests were also performed. RESULTS: The frequency of phenotypes consistent with their genotypes was 70.8% (112/158 cases) and the A2B3 phenotype with the cis-AB01 allele was the most common (31.0%, 49 cases) among them. The frequency of phenotypes inconsistent with their genotypes was 29.1% (46/158 cases) and the A1B3 phenotype was the most frequently recovered case (5.1%, 8 cases). Family study showed differential phenotype expression depending on the co-inherited ABO allele in five families with the B306, cis-AB01, Ael02, Aw14, or B305 allele and also showed a typical inheritance of a chimera with A102/B101/O04. CONCLUSION: We propose that ABO genotyping using PCR-direct sequencing is useful for the resolution of ABO discrepancies and for the investigation of ABO subgroups based on six years' experience. In addition, family study for analysis of phenotypic patterns of ABO subgroups is also crucial to ABO genotyping.

Allele-related Variation in Minisatellite Repeats Involved in Transcription of the ABO Gene in Korean Blood Donors

BACKGROUND: The CBF/NF-Y enhancer region of ABO gene reported to contain 43bp minisatellite tandem repeats has been rarely reported. We describe here the relationship between minisatellite tandem repeats and ABO alleles in samples from Korean population with common ABO blood group and rare ABO subgroup. METHODS: Sixty one cases of ABO subgroup (14 A2, 12 A2B, 1 Aweak, 7 AweakB, 11 B3, 5 A1B3, 1 A1Bweak, 2 Bweak, and 8 cis-AB) and 41 cases of common ABO blood group (13 A, 6 AB, 11 B, and 11 O) were obtained from healthy donors at the Gwangju-Chonnam Red Cross Blood Center between Sep 2004 and Aug 2005. Red cells were phenotyped by standard serologic tests and genotyped by direct DNA sequencing exon 6 and 7 of the ABO gene. The minisatellite repeats were analyzed by PCR method. RESULTS: The ABO*A101 and *A102 had only one repeat, *B101, *O01 and *O02 had 4 repeats in common ABO blood group, while the *A102, *cis-AB01, and *Aw10 had only one minisatellite repeat and *A201, *A204, *B101, *Bw03, *B306, *O01, and *O02 alleles had 4 repeats and unexpectedly 3 A2 cases with *A102 had 4 repeats in the rare ABO subgroup. CONCLUSION: The minisatellite repeats found in Koreans correlate well with ABO alleles in sample common ABO phenotype, but do not completely correlate with those of ABO subgroup. We revealed here a pattern of the minisatellite repeats in various ABO subgroup in Korea.

A Case of Ael with Anti-A / 대한수혈학회지

We report a case of Ael in a 44-year old woman. The patient' red cells were typed as O and her serum had both anti-A and anti-B, but the agglutination strength with A1 cell was weaker (2+) than with B cell (4+) in her serum. Additional tests showed that the red cells were not agglutinated by anti-A,B and A antigen on patient' RBC was demonstrated by adsorption-elution test. Her saliva contained H but no A substance, and the ABO genotyping test identified her blood type as AO. We concluded that this was a case of blood type Ael with anti-A.

A Case of Ael with Anti-A

We report a case of Ael in a 44-year old woman. The patient s red cells were typed as 0 and her serum had both anti-A and anti-B, but the agglutination strength with Al cell was weaker (2+) than with B cell (4+) in her serum. Additional tests showed that the red cells were not agglutinated by anti-A,B and A antigen on patient s RBC was demonstrated by adsorption-elution test. Her saliva contained H but no A substance, and the ABO genotyping test identified her blood type as AO. We concluded that this was a case of blood type Ael with anti-A. (Korean J Blood Transfusion 10(1): 69 75, 1999)

Molecular study on Ax subgroup in Chinese population / 中国输血杂志

Objective To study Ax subgroup’s molecular characteristics in Chinese Han population. Methods Eight samples suspected as Ax subgroup were analyzed and duplex PCR RFLP test was used to determine the primary ABO genotypes. These samples were then analyzed by another PCR RFLP test to identify whether there was an nt646 “T” to “A” mutation within the exon 7 of ABO gene, which was a known mutation related to most Ax phenotypes. Samples with discrepancy between serological and gene typing were chosen for further T A cloning and sequence analysis. Results Four out of all tested samples had the known nt646 “T” to “A” mutation. An A *weak01 allele including nt407 and nt467 “C” to “T” mis sense mutation was detected in this study. Moreover, a novel Ax allele with a new single nucleotide C to T mutation was detected at nt745. Another 2 unrelated samples were suspected as AxB through serological test, both of which contained higher quantities of anti A and showed strong agglutination with anti H. And their initial genotypes were BO, and sequence analysis clarified that both had normal O gene and novel nt640 “A” to “G” mutation in their B alleles. Conclusion The novel Ax alleles, one kind of novel B(A) allele and one A *weak01 allele in Chinese Han individuals,have been detected. B(A) phenotypes should have their molecular biology bases as well as other ABO subgroups.