| 1. |
- Olsson, Martin L, et al.
(author)
-
A clinically applicable method for determining the three major alleles at the Duffy (FY) blood group locus using polymerase chain reaction with allele-specific primers
- 1998
-
In: Transfusion. - 1537-2995. ; 38:2, s. 168-173
-
Journal article (peer-reviewed)abstract
- BACKGROUND: The clinically significant antigens of the Duffy (Fy [FY]) blood group system are expressed on the red cell form of the FY glycoprotein, a promiscuous chemokine receptor and also a receptor for malarial parasites. After the cloning of cDNA coding for FY glycoprotein, the molecular basis of the three major alleles (Fya/Fyb/Fy) has been established. Because of the mistyping of the silent Fy allele as Fyb, the error rate of current genotyping methods is high in black populations. STUDY DESIGN AND METHODS: Two hundred blood donors (European whites and African Blacks) and some amniotic DNA samples were investigated by a new allele-specific primer polymerase chain reaction technique. Sense primers corresponding to normal and GATA-1-mutated FY gene promoter region sequences were combined with antisense primers discriminating the Fya/Fyb polymorphism. RESULTS: Complete correlation between FY phenotypes and genotypes was obtained in all samples studied, although, in two whites and one black, serology showed weak Fyb expression while polymerase chain reaction indicated a Fyb allele. Gene frequencies were calculated. CONCLUSION: This simple and rapid polymerase chain reaction method was shown to detect the three common alleles at the FY locus in two representative ethnic populations. Its future use as an independent technique in red cell FY investigations and for fetal genotyping in hemolytic disease of the newborn is predicted.
|
|
| 2. |
- Hansen, T, et al.
(author)
-
Different genotypes causing indiscernible patterns of A expression on A(el) red blood cells as visualized by scanning immunogold electron microscopy
- 1998
-
In: Vox Sanguinis. - 1423-0410. ; 75:1, s. 47-51
-
Journal article (peer-reviewed)abstract
- BACKGROUND AND OBJECTIVES: The published sequence of the weak. A subgroup Ael gene from Swedish individuals showed a G insertion in exon VII, causing a frameshift at codon 268 (the A1 gene has 353 codons). We wished to sequence exons VI and VII of two Norwegian Ael individuals and compare the expression of A substance on RBC from different Ael individuals. MATERIALS AND METHODS: Exon VI and VII were amplified by PCR, cloned in M13 and sequenced. A structure expression on Ael RBC was studied by the immunogold technique. RESULTS: In contrast to the Swedish Ael individuals, the two Norwegians had consensus A1 sequences in exon VI and VII. However, the patterns of A expression were indiscernible from the Swedish cases as visualized by immunogold labeling in SEM. In both cases, a few (1-2%) RBC were very strongly labeled, some were weakly labeled and the majority (95%) were unlabeled. CONCLUSION: Although some Ael individuals have an inserted nucleotide in exon VII of the ABO gene, others have consensus A1 sequence in exon VI and VII. However, we could not find any differences in phenotype by immunogold labeling in SEM.
|
|
| 3. |
- Irshaid, N M, et al.
(author)
-
Allele-related variation in minisatellite repeats involved in the transcription of the blood group ABO gene
- 1999
-
In: Transfusion Medicine. - : Wiley. - 0958-7578 .- 1365-3148. ; 9:3, s. 219-226
-
Journal article (peer-reviewed)abstract
- Since the cloning in 1990 of cDNA corresponding to mRNA transcribed at the blood group ABO locus, polymorphisms at the ABO locus and phenotype-genotype correlation have been analysed by several investigators. An enhancer-active minisatellite motif reported to contain four 43-bp repeats has been analysed by PCR in blood samples from 160 random Swedish blood donors. Different sizes of the DNA fragments obtained led to further analysis by direct sequencing. Fragments with either one or four 43-bp repeats were identified. A nucleotide substitution (G-->A) at nt. 41 of 43 was found in all alleles with only one repeat. Correlation with the ABO genotypes of the samples, as determined by a panel of ABO genotyping techniques, revealed an allele-related variable number of tandem repeats (VNTR). The A1 and the infrequent O2 allele had only one repeat whilst A2, B, O1 and O1v had four repeats and thus generated longer (by 129 bp) fragments. A further 74 samples obtained from various geographical areas/ethnic groups indicated a widespread correlation with few exceptions. In conclusion, a novel ABO polymorphism located in the 5'-nontranslated region involved in transcriptional regulation of the ABO gene is reported and its relationship to common alleles at this locus defined.
|
|
| 4. |
- Irshaid, N M, et al.
(author)
-
Genomic typing of the Kidd blood group locus by a single-tube allele-specific primer PCR technique
- 1998
-
In: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 102:4, s. 1010-1014
-
Journal article (peer-reviewed)abstract
- The Kidd (JK) blood group system is clinically important in transfusion medicine. Alloantibodies to antigens in this system may be produced following blood transfusion or during pregnancy and can result in serious haemolytic transfusion reactions and haemolytic disease of the newborn (HDN). JK antigens on erythrocytes are carried by glycoproteins with the capacity to transport urea through cell membranes. cDNA complementary to mRNA transcribed at the JK locus was cloned in 1994. The molecular basis of the Jk(a)/Jk(b) blood group polymorphism was recently shown to be a single nucleotide substitution predicting an amino acid change (Asp280Asn) in an extracellular loop of the JK glycoprotein. After confirmation of the JK gene polymorphism we developed a rapid and robust technique for JK genotyping with allele-specific primers in a single-tube PCR. In addition, a 217 bp intron located at nucleotides 811-812 in the JK gene was found and sequenced. The genotyping test was validated with samples from 106 Caucasian Swedish and 13 Black South African random blood donors. Complete phenotype-genotype correlations were obtained. However, four Jk(a-b-) samples of Polynesian and Finnish origin typed as Jk(b)Jk(b). Potential use of the presented method can be predicted in clinical transfusion medicine including prenatal determination of the JK genotype in a fetus at risk for HDN caused by JK antibodies.
|
|
| 5. |
- Olsson, Martin L, et al.
(author)
-
A rapid and simple ABO genotype screening method using a novel B/O2 versus A/O2 discriminating nucleotide substitution at the ABO locus
- 1995
-
In: Vox Sanguinis. - 1423-0410. ; 69:3, s. 242-247
-
Journal article (peer-reviewed)abstract
- An ABO genotype screening method discriminating the common alleles A1, A2, B, O1 and O2 at the ABO locus was made possible by the discovery of a novel nucleotide substitution (G1096A) present only in B and O2 alleles. A rapid and reliable single-tube approach using multiplex PCR with four primers amplifying exons 6 and 7 of the ABO genes followed by simultaneous addition of two restriction enzymes was developed and validated in a population of 150 Swedish blood donors. This technique is the most cost-efficient and informative ABO genotyping method reported to date.
|
|
| 6. |
- Olsson, Martin L, et al.
(author)
-
An Ael allele-specific nucleotide insertion at the blood group ABO locus and its detection using a sequence-specific polymerase chain reaction
- 1995
-
In: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 216:2, s. 642-647
-
Journal article (peer-reviewed)abstract
- Genomic DNA from each of four Acl individuals (genotypes AO1, AO1var, AO2) and one AclB individual was used as a template for amplifying exons 6 and 7 of the ABO genes, which were subsequently sequenced. In all the Ael alleles a single nucleotide insertion, compared to the A consensus sequence, was observed that would alter the amino acid sequence of the glycosyltransferase immediately after its postulated nucleotide sugar binding site and furthermore extend the translated protein by 37 amino acids (16 more than the A2 enzyme). A sequence-specific primer PCR assay was developed to detect the nucleotide insertion. It was possible to differentiate all 20 serologically defined Acl/AclB individuals available from 145 blood donors with normal ABO phenotypes and genotypes and 26 individuals with various A subgroups other than A1, A2 and Acl. This mutation explains the Acl phenotype and forms the basis of a method for detecting the Ael allele.
|
|
| 7. |
- Olsson, Martin L, et al.
(author)
-
Evidence for a new type of O allele at the ABO locus, due to a combination of the A2 nucleotide deletion and the Ael nucleotide insertion
- 1996
-
In: Vox Sanguinis. - : Wiley. - 1423-0410 .- 0042-9007. ; 71:2, s. 113-117
-
Journal article (peer-reviewed)abstract
- Using a recently introduced multiplex polymerase chain reaction and restriction fragment length polymorphism ABO genotype screening method we have found an anomalous ABO genotype (A2O1variant) not correlating with the serological phenotype (blood group O). The blood group was confirmed by absorption/elution and detection of blood group substances in saliva. Sequencing of exons 6 and 7 in the ABO genes of the propositus indicated an A2 gene (C467T and C1060-) apparently inactivated by the same single nucleotide insertion recently reported in individuals with the ABO subgroup Ael. Investigation of relatives confirmed the inheritance of this new inactive hybrid allele.
|
|
| 8. |
- Olsson, Martin L, et al.
(author)
-
Frequent occurrence of a variant O1 gene at the blood group ABO locus
- 1996
-
In: Vox Sanguinis. - 1423-0410. ; 70:1, s. 26-30
-
Journal article (peer-reviewed)abstract
- Blood group ABO polymorphism was analysed in genomic DNA isolated from 150 blood donors by restriction endonuclease digestion of three polymerase chain reaction-amplified exons in the ABO genes and by sequencing of randomly selected samples. An anomalous O1 allele first described in a cancer cell line is now shown to account for approximately 40% of the O alleles described to date. This is 10 times more frequent than the only other known variant O allele (O2). This variant O1 allele has at least seven point mutations when compared to the consensus gene, in addition to the deletion characterising the normal O1 allele.
|
|
| 9. |
- Olsson, Martin L, et al.
(author)
-
Heterogeneity of the blood group Ax allele: genetic recombination of common alleles can result in the Ax phenotype
- 1998
-
In: Transfusion Medicine. - : Wiley. - 0958-7578 .- 1365-3148. ; 8:3, s. 231-238
-
Journal article (peer-reviewed)abstract
- The Ax phenotype is an important subgroup of the ABO blood group system. Its inheritance does not always follow Mendelian rules and recent studies suggested that different alleles can result in this phenotype. This suggestion has been explored by cloning and sequencing exons 6 and 7 of the ABO gene and the intervening intron from members of six unrelated families expressing the Ax phenotype. Two families showed the previously described T646A 'Ax' mutation as the only deviation from the consensus A1 allele. In two other families the Ax phenotype was inherited as two different recombinational gene products. Combination of exon 6 derived from A or B/O2 alleles with exon 7 from the O1v allele created two novel alleles that have four O1v-characteristic nucleotide substitutions in exon 7, including T646A. Sequencing and analysis of polymorphisms in intron 6 defined the crossing-over zones of these hybrid alleles. Southern blot confirmed the hybrid formation by detecting ABO-related polymorphisms approximately 1.35 kb downstream from the ABO reading frame. The remaining two families expressed the Ax phenotype via an allele having A2-specific mutations. Thus, a heterogeneous molecular background leads to the serologically defined Ax phenotype and may well explain the different modes of inheritance observed.
|
|
| 10. |
- Olsson, Martin L, et al.
(author)
-
Heterogeneity of the O alleles at the blood group ABO locus in Amerindians
- 1998
-
In: Vox Sanguinis. - : Wiley. - 1423-0410 .- 0042-9007. ; 74:1, s. 46-50
-
Journal article (peer-reviewed)abstract
- BACKGROUND AND OBJECTIVES: Amerindians are blood group O, but the distribution of the various O alleles is unknown. Their ABO genotypes were compared with samples from other Brazilian ethnic groups. MATERIALS AND METHODS: Genomic DNA was examined by PCR-RFLP analysis, PCR-SSP and direct sequencing. RESULTS: An unusual allele distribution was found, with 91% of the O alleles being O1variant. Almost half of these alleles had an additional novel mutation (G542A), which was also detected in a few other Brazilian and European samples. The O alleles correlated completely with ABO-related haplotypes previously determined by Southern blot. CONCLUSION: The three Amerindian tribes represent a homogeneous (ABO blood group) population, except for the G542A mutation. The presence of this mutation in all other populations examined suggests that it originated before the migration of man into America.
|
|
