| 1. |
- Adamovic, Svetlana, 1965, et al.
(författare)
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Fine mapping study in Scandinavian families suggests association between coeliac disease and haplotypes in chromosome region 5q32.
- 2008
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Ingår i: Tissue Antigens. - : Wiley. - 1399-0039 .- 0001-2815. ; 71:1, s. 27-34
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Tidskriftsartikel (refereegranskat)abstract
- The previous genome-wide scan in Scandinavian families supported earlier evidence for linkage of a region on chromosome 5 (5q31–33) to coeliac disease. This study deals with further genetic mapping of an 18 cM region, spanning from marker GAh18A (131.87 Mb) to D5S640 (149.96 Mb). Linkage and association analyses were performed in a two-step approach. First, seven microsatellites were added. Strong evidence for linkage was obtained with a Zlr score of 3.96, Pnc = 4 × 10−5 at marker D5S436. The strongest association was with a haplotype consisting of the markers D5S2033 and D5S2490 (Pnc < 0.001). In the second step, we added 17 microsatellites and 69 single nucleotide polymorphisms (SNPs) to the analysis. These markers were located close to or within candidate genes across the region of approximately 7 Mb beneath the linkage peak marked by D5S2017 and D5S812. A substantial increase of the linkage signal with a maximum Zlr score of 4.6 at marker rs1972644 (Pnc = 2 × 10−6) was obtained and several SNPs showed association. Seven SNPs that individually showed the strongest association were genotyped in a second independent family sample set (225 trios). In the trio family sample as well as in the multiplex family sample, the strongest association was found with SNPs within the region flanked by the associated microsatellites D5S2033 and D5S2490 at 5q32.
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| 2. |
- Amundsen, Silja Svanström, et al.
(författare)
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Four novel coeliac disease regions replicated in an association study of a Swedish-Norwegian family cohort.
- 2010
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Ingår i: Genes and immunity. - : Springer Science and Business Media LLC. - 1476-5470 .- 1466-4879. ; 11:1, s. 79-86
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Tidskriftsartikel (refereegranskat)abstract
- Recent genome-wide association studies have identified 1q31 (RGS1), 2q11-12 (IL18RAP), 3p21 (CCR1/CCR3/CCR2), 3q25-26 (IL12A/SCHIP1), 3q28 (LPP), 4q27 (IL2/IL21), 6q25 (TAGAP) and 12q24 (SH2B3) as susceptibility regions for coeliac disease (CD). We have earlier replicated association with the IL2/IL21 region. This study aimed at replicating the remaining regions in a family cohort using the transmission disequilibrium test, which is not prone to population stratification as a source of false-positive results. Nine single nucleotide polymorphisms (SNPs) within these regions were genotyped in 325 Swedish-Norwegian CD families. We found significant associations with the same alleles in the regions 1q31 (rs2816316; P(nc)=0.0060), 3p21 (rs6441961; P(nc)=0.0006), 3q25-26 (rs17810564; P(nc)=0.0316 and rs9811792; P(nc)=0.0434) and 3q28 (rs1464510; P(nc)=0.0037). Borderline, but non-significant, associations were found for rs917997 (IL18RAP), whereas no evidence for association could be obtained for rs13015714 (IL18RAP) or rs1738074 (TAGAP). The lack of replication of the latter SNPs could be because of limited power. rs3184504 (SH2B3) was not analysed because of assay failure. The most significantly associated region, 3p21 (CCR1/CCR3/CCR2), was further analysed by typing of 30 SNPs, with the aim of identifying the causal variant responsible for the initial association. Several SNPs showed association with CD, but none displayed associations stronger than rs6441961, nor did any of them add to the effect initially marked by rs6441961 in a conditional analysis. However, differential effects of rs6441961(*)C carrying haplotypes were indicated, and we thus cannot exclude the possibility that our inability to obtain evidence for multiple independent effects in the CCR1/CCR3/CCR2 gene region was related to a power issue.
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