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Biomedical subjects

N Morling

Publications and source records attributed to N Morling.

At least 19 recordsLinked to original sources
PubMed1996

PCR typing of DNA fragments of the two short tandem repeat (STR) systems upstream of the human myelin basic protein (MBP) gene in Danes and Greenland Eskimos.

DNA from the double short tandem repeat (STR) system MBP (locus 18q23-pter) was amplified by the polymerase chain reaction (PCR) and the two polymorphic repeat systems were separated by cutting with the restriction enzyme NlaIII. The lengths of the DNA fragments of the two MBP STR systems MBP-A and MBP-B were analyzed by vertical electrophoresis in polyacrylamide gels followed by silver staining. DNA samples from 112 unrelated Danes, 140 unrelated Greenland Eskimos, and 88 Danish mother/child pairs were analyzed. The distributions of MBP phenotypes were in Hardy-Weinberg equilibrium in both the Eskimo and Danish populations. Significant differences were observed between the distribution of fragments ('alleles') in Greenland Eskimos and in Danes. The allele MBP-A7 was considerably more frequent in Eskimos (0.2214) than in Danes (0.0775) and also the allele MBP-B9 was considerably more frequent in Eskimos (0.225) than in Danes (0.06). Strong gametic associations were found between fragments from MBP-A and MBP-B series in both Danes and Eskimos. Some of the associations were different in Danes and Eskimos. In the 88 Danish mother/child pairs, the segregation of the MBP genotypes were in accordance with a genetic model of co-dominant inheritance and no mutation was found. Two MBP STR regions with irregular structures were sequenced. One fragment had a single base G to A transition at position 124 in the primer binding region between the MBP-A and MBP-B regions. In the other fragment, a deletion starting at position 117 and including the primer binding region between MBP-A and MBP-B regions was found.

Alleles↗
PubMed1995

HLA-DQA1 typing in Danes by two polymerase chain reaction (PCR) based methods.

A total of 280 persons were HLA-DQA1 typed by two different polymerase chain reaction (PCR) based methods; (i) a reverse dot-blot (RDB) method, which can differentiate between six alleles, and (ii) a combined PCR-restriction fragment length polymorphism (PCR-RFLP) and allele-specific amplification (ASA) method, which together recognise eight alleles. In 146 unrelated Danish individuals, the HLA-DQA1 alleles were in Hardy-Weinberg equilibrium. For identity testing, the power of discrimination (PD) of HLA-DQA1 was 0.932 with the RDB method and 0.942 with the PCR-RFLP/ASA method. For paternity testing, the theoretical chance of exclusion in HLA-DQA1 of non-fathers was 0.634 with the RDB method and 0.660 with the PCR-RFLP/ASA method.

Alleles↗
PubMed1994

An investigation of the HUMVWA31A locus in British Caucasians.

A number of short tandem repeat (STR) loci are currently being examined for their usefulness as markers of identity; HUMVWA31A is one such locus. We used a high-sieving agarose technique to type 200 British Caucasians for this locus. Comparison of the resultant allele frequencies with other published databases showed that their distributions were similar. Observed heterozygosity was similar to that reported in other population studies but significantly lower than expected. A goodness of fit analysis of observed and expected genotypes was highly significant, suggesting a deviation from Hardy-Weinberg equilibrium, although reports from other populations appeared not to show such differences. The possibility that mistyping had led to an erroneous statistic was investigated by detailed examination of samples within our own laboratory and in two other laboratories, involving verification of the agarose typing by both automated fluorescent detection techniques, and sequencing. Other reported deviations from Hardy-Weinberg equilibrium in STR systems are discussed.

Alleles↗
PubMed1994

PCR typing of DNA fragments of the short tandem repeat (STR) system HUMTH01 in Danes and Greenland Eskimos.

DNA from the short tandem repeat (STR) system HUMTH01 was amplified by the polymerase chain reaction (PCR) and analyzed by vertical electrophoresis in polyacrylamide gels followed by silver staining. DNA samples from 100 unrelated Danes, 147 unrelated Greenland Eskimos, and 89 Danish mother/child pairs were analyzed. Significant differences were observed between the distribution of fragments ('alleles'), whereby allele number 7 was considerably more frequent in Eskimos (0.687) than in Danes (0.201). The distributions of HUMTH01 phenotypes were in Hardy-Weinberg equilibrium in both the Eskimo and Danish populations. In the 89 Danish mother/child pairs, the segregation of the HUMTH01 genotypes was in accordance with the genetic model of co-dominant inheritance and no mutations were found. In a blind trial, DNA samples from 40 unrelated Danes were investigated by one of us in Copenhagen, at the FBI Forensic Science Research and Training Center (FSRTC), Quantico, and at the Institut für Rechtsmedizin, Münster, Germany. Concordant HUMTH01 types were found in 39 out of 40 individuals. The allele which led to discrepant typing results was assigned type 9.3 in two laboratories and type 10 in one laboratory.

Alleles↗
PubMed1994

Graft-derived anti-HPA-2b production after allogeneic bone-marrow transplantation.

We report on a male who received a bone-marrow allograft from his HLA identical sister for acute myelogenous leukaemia. After transplantation, the patient suffered from refractoriness to the transfusions of HLA-matched platelets and a strong platelet-specific antibody, anti-HPA-2b, of IgG1 subclass was demonstrated in the patient's serum. In the serum of the bone-marrow donor a weak IgG1 anti-HPA-2b was demonstrated. IgG allotyping of the patient and donor showed identical results. We could not determine the origin of the anti-HPA-2b, although we hypothesize that the anti-HPA-2b was produced by immunocompetent donor lymphocytes infused with the suspension of bone-marrow cells.

Antigens, Human Platelet↗
PubMed1994

DNA polymorphism of HLA class II genes in systemic lupus erythematosus.

We investigated the DNA restriction fragment length polymorphism (RFLP) of the major histocompatibility complex (MHC) genes: HLA-DRB, -DQA, -DQB, -DPB in 24 Danish patients with systemic lupus erythematosus (SLE) and in 102 healthy Danes. A highly significant increase of the frequency of the DR3- and DRw6-associated 7.00 kb DRB TaqI DNA fragment was found in SLE patients compared to normal controls (83.3% vs 35.5%; RR = 9.1, p < 10(-4). The frequencies of the DQA1*0501-associated 4.56 kb DQA TaqI fragment and the DRB3*01/03-associated 9.79 kb TaqI fragment were also found to be significantly increased in SLE patients (70.8% vs 29.7%; RR = 5.8, p < 10(-2) for the DQA fragment and 70.8% vs 36.1%; RR = 4.3, p < 0.05 for the DRB3 fragment). Less extensive and insignificant increases of the frequencies of the DR3-associated DQB and DPB fragments were observed. The frequencies of the DR2-associated DRB, DQA, and DQB fragments were comparable to those found in normal controls.

DNA↗
PubMed1994

Group specific component in serum and otosclerosis: no association.

An earlier Swedish study suggested a positive association between otosclerosis and the group-specific component GC*1F marker. We investigated the distribution of GC subtypes in 101 Danish patients with otosclerosis who all had surgery performed in the county of Funen. Compared to 1674 Danish controls we found no evidence of any association between markers from the GC serum protein system and otosclerosis.

Female↗
PubMed1993

Paternity testing with VNTR DNA systems. I. Matching criteria and population frequencies of the VNTR systems D2S44, D5S43, D7S21, D7S22, and D12S11 in Danes.

Paternity testing using DNA polymorphism of variable numbers of tandem repeat (VNTR) regions with restriction fragment length polymorphism (RFLP) was implemented. HinfI-digested DNA was separated by electrophoresis in agarose gels and hybridized with radiolabelled probes detecting the VNTR-systems D2S44 (YNH24), D5S43 (MS8), D7S21 (MS31), D7S22 (g3), and D12S11 (MS43a). The intra gel variability of 970 duplicate investigations on the same gel of DNA from 122 individuals showed no differences exceeding 1.25 mm between the positions of the corresponding DNA fragments. The comparison of 1,624 DNA fragments from 342 mother/child pairs showed only one difference above 1.25 mm which was interpreted as a mutation. Based on these observations, we decided to consider an intra gel difference above 1.25 mm between the non-maternal DNA fragment of the child and the nearest DNA fragment of the putative father as an exclusion in paternity testing. This matching criterion was used for the comparisons of 1,197 DNA fragment differences in 247 pairs of children and putative fathers who had not been excluded by conventional marker systems. In all of these cases, the migration differences between the DNA fragments of non-excluded men and the DNA fragments of the children were less than 1.25 mm except in 6 cases (0.5%). The man/child differences in all of 227 false trios exceeded 1.25 mm in 2 or more of the 5 VNTR systems investigated. Matching criteria for inter gel comparisons in paternity testing were established. The frequency distribution of HinfI digested DNA fragments of the 5 VNTR systems in 650 unrelated Danes is presented and the raw data is available.

Adult↗
PubMed1993

Paternity testing with VNTR DNA systems. II. Evaluation of 271 cases of disputed paternity with the VNTR systems D2S44, D5S43, D7S21, D7S22, and D12S11.

Paternity testing was carried out in 271 cases of disputed paternity using the 5 VNTR systems D2S44 (YNH24), D5S43 (MS8), D7S21 (MS31), D7S22 (g3), and D12S11 (MS43a), and 10-15 conventional marker systems including the HLA-A,B system. By means of the matching criteria for the VNTR systems established elsewhere (Morling & Hansen 1992), all 70 unrelated men who had been excluded by conventional typing were also excluded with 2 or more VNTR systems. Based on the observed exclusion frequencies for the 5 VNTR systems, a theoretical exclusion rate exceeding 0.999 could be obtained. A total of 350 father/child pairs were studied and in 3 paternity cases and one immigrant family, the alleged fathers were excluded solely by one of the 5 VNTR systems possibly reflecting mutations. No mother/child exclusions were observed among 350 mother/child pairs. Linkage analysis between the syntenic systems D7S21 (MS31) and D7S22 (g3) was performed in 29 informative families with 81 children and revealed a recombination distance of about 31 cM. The positive evidence for paternity provided by the 5 VNTR systems in cases with non-exclusions is discussed.

Adult↗
PubMed1993

Genetic investigations in immigration cases and frequencies of DNA fragments of the VNTR systems D2S44, D5S43, D7S21, D7S22, and D12S11 in Turks.

We have included investigations of the DNA polymorphism of variable numbers of tandem repeat (VNTR) regions with restriction fragment length polymorphism (RFLP) in the genetic evaluations in immigrant cases. HinfI-digested DNA was separated by electrophoresis in agarose gels and hybridized with radiolabelled probes detecting the VNTR systems D2S44 (YNH24), D5S43 (MS8), D7S21 (MS31), D7S22 (g3), and D12S11 (MS43a). We used the matching criterion for paternity testing for the parent/child comparisons, i.e. non-match if the intra gel difference exceeded 1.25 mm. A total of 43 immigration cases involving mainly Turks were investigated with DNA technique in parallel with investigations of 10-15 conventional systems. One man was excluded from paternity by both conventional and DNA investigations. Non-exclusion was observed with both conventional and DNA systems in 97 putative mother/child pairs and in 96 putative father/child pairs. In a putative father/child combination with non-exclusion in 18 genetic systems, a single genetic inconsistency ('exclusion') in D7S21 (MS31) was observed. The frequency distributions of HinfI digested DNA fragments of the five VNTR systems in 105 Turks are presented.

Adult↗
PubMed1993

Analysis of the locus D1S80 by amplified fragment length polymorphism technique (AMP-FLP). Frequency distribution in Danes. Intra and inter laboratory reproducibility of the technique.

DNA from the locus D1S80 was amplified by polymerase chain reaction (PCR) and analyzed by electrophoresis in vertical polyacrylamide gels followed by silverstaining. DNA samples from 119 unrelated Danes and 97 mother/child pairs were examined. The amplified fragment length polymorphism (AMP-FLP) analysis of the D1S80 locus demonstrated 21 alleles and a heterozygosity of 77%. Of the 231 possible phenotypes, 57 were observed. All mother/child pairs shared at least one D1S80 allele. The D1S80 typing results in 70 Danes were compared to the results obtained on the same samples in another laboratory and the results were concordant in all cases.

Adult↗
PubMed1992

DNA polymorphism of HLA class II genes in primary biliary cirrhosis.

We investigated the DNA restriction fragment length polymorphism of the major histocompatibility complex class II genes: HLA-DRB, -DQA, -DQB, DPA, -DPB, the serologically defined HLA-A, B, C, DR antigens, and the primed lymphocyte typing defined HLA-DP antigens in 23 Danish patients with primary biliary cirrhosis (PBC) and in healthy Danes. The following genetic markers were found with increased frequencies in PBC: HLA-B8 (relative risk, RR = 2.4, P less than 0.05, 'corrected' P greater than 0.05), HLA-DR3 (RR = 3.4, P less than 0.01, 'corrected' P less than 0.05), the DRB3*01/02/03 (DRw52) associated DRB Bgl II 9.1 kilobase (kb) fragment (RR = 2.9; P less than 0.05, 'corrected' P greater than 0.05), the DQA1*0501 associated DQA Taq I 4.8 kb fragment (RR = 3.1; P less than 0.05, 'corrected' P greater than 0.05), the DQB1*0201 (DQw2) associated DQB Hin dIII 11.5 kb fragment (RR = 3.1; P less than 0.05, 'corrected' P greater than 0.05). No DNA fragments specific for DRB1*0301 (DR3) could be identified. The frequencies in PBC of other genetic markers including DRw8, DRB1*08, HLA-DP antigens, DPA, and DPB genes did not differ significantly from those in controls. The associations between PBC and B8, DR3, DQA1*0501, and DQB1*0201, which are frequently found together on the same haplotype, are at variance with recent reports on associations between PBC and Drw8. The discrepancy suggests that PBC is genetically heterogenous.

Genes, MHC Class II↗
PubMed1992

HLA-DPB1 typing with polymerase chain reaction and restriction fragment length polymorphism technique in Danes.

We have used the polymerase chain reaction (PCR) in combination with the restriction fragment length polymorphism (RFLP) technique for HLA-DBP1 typing. After PCR amplification of the polymorphic second exon of the HLA-DPB1 locus, the PCR product was digested with seven allele-specific restriction endonucleases: RsaI, FokI, ApaI, SacI, BstUI, EcoNI, and DdeI, and the DNA fragments were separated by electrophoresis in agarose gels. Altogether, 71 individuals were investigated and 16 different HLA-DPB1 types were observed in 26 different heterozygotic combinations, as well as five possible homozygotes. Four heterozygotes could not be unequivocally typed with the PCR-RFLP method. The HLA-DPB1 typing results obtained with the PCR-RFLP method were compared with the typing results obtained with PCR allele-specific oligonucleotides (PCR-ASO) in 50 individuals. The results obtained with the two methods were concordant in 84% of the cases. One of the HLA-DPB1 types was discrepant in six heterozygotes, both HLA-DPB1 types were discrepant in one heterozygote, and in one individual two HLA-DPB1 types were identified with the PCR-RFLP technique while only one HLA-DPB1 type could be demonstrated with the PCR-ASO technique. The frequencies of the HLA-DPB1 genotypes deduced from the results of PCR-RFLP typing were estimated in 71 healthy Danes.

Adult↗
PubMed1991

Restriction fragment length polymorphism of two HLA-B-associated transcripts genes in five autoimmune diseases.

The restriction fragment length polymorphism of the two human HLA-B-associated transcripts (BATs) genes, BAT1 and BAT2, identifying polymorphic bands of 12, 8, 2.5, and 1.1 kb, and at 3.3, 2.7, 2.3, and 0.9 kb, respectively, was investigated in patients with primary biliary cirrhosis (PBC), systemic lupus erythematosus (SLE), pauciarticular juvenile rheumatoid arthritis (P-JRA), rheumatoid arthritis (RA), and primary Sjögren's syndrome (pSS), and in healthy Danes. The BAT2/RsaI 2.7-kb band fragment was more frequent in PBC, pSS, and SLE than in controls, but the p values did not reach significance when corrected for multiple comparisons. For pSS and SLE, the associations may be secondary to primary associations with HLA-B8 because the BAT2/RsaI 2.3-kb band, which is allelic to the BAT2/RsaI 2.7-kb band, is strongly negatively associated with HLA-B8 and HLA-DR3. The only significance obtained shows that the HLA-B8 frequency is increased in BAT2/RsaI 2.7-kb positive pSS patients as compared to the corresponding controls indicating that the HLA-B8 association may be strongest. No missing or extra DNA fragments were observed in the disease groups when compared with controls indicating that gross deletions or duplications of the BAT1 and BAT2 genes in the patients are unlikely. In conclusions, it cannot be excluded that the BAT2/RsaI 2.7-kb band may contribute to the susceptibility to PBC, pSS, and SLE.

Autoimmune Diseases↗