G van der Steege

Association with HLA class I in Epstein-Barr-virus-positive and with HLA class III in Epstein-Barr-virus-negative Hodgkin's lymphoma.

BACKGROUND Associations of Hodgkins lymphoma with HLA have been reported for many years. In 20-40% of patients with this disorder, Epstein-Barr virus (EBV) is present in the neoplastic cells. Because presentation of EBV antigenic peptides can elicit vigorous immune responses, we investigated associations of the HLA region with EBV-positive and EBV-negative Hodgkins lymphoma. METHODS In a retrospective, population-based study, patients with Hodgkins lymphoma were reclassified according to the WHO classification, and EBV status was assessed by in-situ hybridisation of EBV-encoded small RNAs. Germline DNA was isolated from 200 patients diagnosed between 1987 and 2000 and from their first-degree relatives. Genotyping was done with 33 microsatellite markers spanning the entire HLA region and two single-nucleotide polymorphisms in the genes for tumour necrosis factor alpha and beta. Classic association analysis and the haplotype sharing statistic were used to compare patients with controls. FINDINGS Classic association analysis (but not the haplotype sharing statistic) showed an association of consecutive markers D6S265 and D6S510 (p=0.0002 and 0.0003), located in the HLA class I region, with EBV-positive lymphomas. The haplotype sharing statistic (but not classic association analysis) showed a significant difference in mean haplotype sharing between patients and controls surrounding marker D6S273 (p=0.00003), located in HLA class III. INTERPRETATION Areas within the HLA class I and class III regions are associated with susceptibility to Hodgkins lymphoma, the association with class I being specific for EBV-positive disease. This finding strongly suggests that antigenic presentation of EBV-derived peptides is involved in the pathogenesis of EBV-involved Hodgkins lymphoma. RELEVANCE TO PRACTICE Polymorphisms in the HLA region could explain ethnic variation in the incidence of Hodgkins lymphoma. The association of EBV-positive Hodgkins lymphoma with HLA class I suggests that this polymorphism might affect the proper presentation of EBV antigens to cytotoxic T lymphocytes.

Susceptibility to Buruli ulcer is associated with the SLC11A1 (NRAMP1) D543N polymorphism

Similar to other mycobacterial diseases, susceptibility to Buruli ulcer (Mycobacterium ulcerans infection) may be determined by host genetic factors. We investigated the role of SLC11A1 (NRAMP1) in Buruli ulcer because of its associations with both tuberculosis and leprosy. We enrolled 182 Buruli ulcer patients (102 with positive laboratory confirmation) and 191 healthy neighbourhood-matched controls in Ghana, and studied three polymorphisms in the SLC11A1 gene: 3′ UTR TGTG ins/del, D543N G/A, and INT4 G/C. Finger prick blood samples from study subjects were dried on filter papers (FTA) and processed. D543N was significantly associated with Buruli ulcer: the odds ratio (adjusted for gender, age, and region of the participant) of the GA genotype versus the GG genotype was 2.89 (95% confidence intervals (CI): 1.41–5.91). We conclude that a genetic polymorphism in the SLC11A1 gene plays a role in susceptibility to develop Buruli ulcer, with an estimated 13% population attributable risk.

Analysis of C1q polymorphisms suggests association with systemic lupus erythematosus, serum C1q and CH50 levels and disease severity

Background: Several findings link systemic lupus erythematosus (SLE) with C1q, the first molecule of the classical complement pathway. Polymorphisms of the C1qA gene are associated with low serum C1q levels in patients with cutaneous LE, but C1q polymorphisms have not been studied in patients with systemic lupus. Objective: To determine whether polymorphisms of the C1q genes are associated with SLE, disease phenotypes, serum C1q and CH50 levels. Methods: DNA for genetic analysis was obtained from 103 Caucasian patients with SLE and their family members. Five tag single nucleotide polymorphisms (tag SNPs) served as unique markers for underlying SNPs in the genes of the C1q protein. The pedigree disequilibrium test (PDT) was applied to trios to determine association of markers with SLE, SLE phenotypes, low serum C1q and low CH50. Single SNP association and haplotype analysis was also performed. Results: The PDT revealed a significant association of the tag SNP rs631090 (covering the C1qB gene) with SLE (p = 0.02). Rs631090 was moderately associated with low serum C1q levels (p = 0.06). In addition, the tag SNPs rs292001 and rs294183 were associated with more severe SLE (Systemic Lupus Erythematosus International Collaborating Clinics (SLICC) damage index score>0; p = 0.007 and p = 0.02, respectively). Haplotype analysis and single SNP association analysis showed no significant associations, but additional analyses revealed that marker rs587585 is associated with low serum C1q and CH50 levels. Conclusions: C1q polymorphisms are associated with SLE, serum C1q and CH50 levels in a stable founder population of patients with SLE. Although the studied population was small and allele frequencies were low, this is the first study to suggest an association of C1q polymorphisms with SLE.

Analysis of the entire HLA region in susceptibility for cervical cancer: a comprehensive study

Background: Infection with human papillomavirus (HPV) is the main cause of cervical cancer and its precursor lesion, cervical intraepithelial neoplasia (CIN). Variability in host immunogenetic background is important in determining the overall cellular immune response to HPV infections. Objective: To determine whether the HLA-DQ or HLA-DR genes, or others in their vicinity, are associated with cervical cancer. Methods: Markers covering the entire HLA region were genotyped in a large sample of CIN and cervical cancer patients and in controls (311 CIN, 695 cervical cancer, 115 family controls, and 586 unrelated controls). Results: Two markers were associated with susceptibility to cervical neoplasia, G511525 and MICA. G511525, close to the region containing the HLA-DQ and HLA-DR genes, was most strongly associated, showing a decrease in frequency of allele 221 from 6.7% to 3.3% in patients with squamous cell cancer (SCC). An association was found for MICA (allele 184) with SCC (odds ratio (OR) = 1.31 (95% confidence interval, 1.13 to 1.53); homozygotes, OR = 1.48 (1.06 to 2.06)). No associations were observed with adenocarcinoma or CIN. Conclusions: There is an association of the region containing the HLA-DQ and HLA-DR genes with the risk of developing squamous cell carcinoma. An increased risk was observed for carriers of allele 184 at the MICA locus, in particular for homozygotes, suggesting a recessive effect.

Heme Oxygenase-1 Genotype of the Donor Is Associated With Graft Survival After Liver Transplantation

Heme oxygenase‐1 (HO‐1) has been suggested as a cytoprotective gene during liver transplantation. Inducibility of HO‐1 is modulated by a (GT)n polymorphism and a single nucleotide polymorphism (SNP) A(‐413)T in the promoter. Both a short (GT)n allele and the A‐allele have been associated with increased HO‐1 promoter activity. In 308 liver transplantations, we assessed donor HO‐1 genotype and correlated this with outcome variables. For (GT)n genotype, livers were divided into two classes: short alleles (<25 repeats; class S) and long alleles (≥25 repeats; class L). In a subset, hepatic messenger ribonucleic acid (mRNA) expression was correlated with genotypes. Graft survival at 1 year was significantly better for A‐allele genotype compared to TT‐genotype (84% vs. 63%, p = 0.004). Graft loss due to primary dysfunction (PDF) occurred more frequently in TT‐genotype compared to A‐receivers (p = 0.03). Recipients of a liver with TT‐genotype had significantly higher serum transaminases after transplantation and hepatic HO‐1 mRNA levels were significantly lower compared to the A‐allele livers (p = 0.03). No differences were found for any outcome variable between class S and LL‐variant of the (GT)n polymorphism. Haplotype analysis confirmed dominance of the A(‐413)T SNP over the (GT)n polymorphism. In conclusion, HO‐1 genotype is associated with outcome after liver transplantation. These findings suggest that HO‐1 mediates graft survival after liver transplantation.

Colorectal cancer and the CHEK2 1100delC mutation

The CHEK2 1100delC mutation was recently identified as a low‐penetrance breast cancer susceptibility allele. The mutation occurred more frequently in families with clustering of breast and colorectal cancers (CRCs) than in families with clustering of breast cancer only. Hence, the 1100delC mutation could also be a low‐penetrance CRC susceptibility allele. To test this hypothesis, we examined the mutation in 629 unselected CRC cases, 230 controls, and 105 selected CRCs diagnosed in patients before age 50. The mutation was observed in 1.6% of unselected patients and in 0.3% of controls (Not significant (NS)). After stratifying unselected patients according to defined genetic risk (on the basis of age at diagnosis and family history of colorectal and endometrial cancer), the highest frequency was observed in high‐risk patients (12.5%), followed by moderate‐risk patients (3.3%), and was lowest in low‐risk patients (1.0%, Ptrend 0.014). In selected patients, 1.6% carried the mutation (NS). Subgroup analyses for tumor localization, gender, and age at diagnosis did not reveal an association with the 1100delC genotype. In addition, a pooled analysis, combining data of one published study in unselected CRC cases and our study, also did not reveal an association. In conclusion, the frequency of the 1100delC genotype was neither significantly increased in unselected CRC patients nor in selected CRC patients diagnosed before age 50. However, after stratifying unselected CRC patients according to defined genetic risk, a significant trend of increasing frequency was observed. Together, the results are consistent with a low‐penetrance effect (OR 1.5–2.0) of the CHEK2 1100delC on CRC risk. Large case–control studies are required to clarify the exact role of the CHEK2 1100delC mutation in CRC.

An extensive screen of the HLA region reveals an independent association of HLA class I and class II with susceptibility for systemic lupus erythematosus

Objectives: The association of systemic lupus erythematosus (SLE) with the human leucocyte antigen (HLA) region is well known. In this study, we analysed the involvement of the HLA region in susceptibility for SLE in a stable founder, Caucasian population of SLE patients. Methods: We performed an extensive screen of the entire HLA region on 103 SLE patients and family‐based controls. Both single locus association analysis and haplotype sharing analysis were performed. The Additional Disease Locus Test (ADLT) was applied to examine the nature of the observed associations and to distinguish true causal associations from associations due to linkage disequilibrium (LD). Results: Significant associations were observed at markers in the HLA class I, class II, and class III regions using both haplotype sharing and single locus methods. The haplotype sharing methods revealed the most significant difference at marker D6S1666 in the HLA class II region (pHSS = 0.00037, pCROSS = 1.7 × 10−5). The most significant result for single locus association was shown at marker D6S265 in the HLA class I region (p = 0.00019). The ADLT demonstrated that these markers represent independent associations. Conclusion: HLA class I, class II, and class III are associated with SLE, but only class I and class II contribute independently to increased risk of SLE.

Two type XVII collagen (BP180) mRNA transcripts in human keratinocytes: A long and a short form

We have analysed BP180 mRNA expression in normal human keratinocytes. Here we report the presence in normal keratinocytes of two COL17A1 transcripts which differ by 0.6 kb in length. Both mRNAs hybridized on Northern blot with probes directed to sequences encoding intracellular and extracellular fragments of BP180. By blast homology search alignments we extended the 3′ untranslated region (3′UTR) of the known BP180 mRNA sequence by 877 bases to completion. Three of 20 cDNAs identified by blast searches contained a 610 bp deletion in this new 3′UTR sequence. Northern blot analysis with a probe complementary to this deleted sequence showed binding only to the larger mRNA. The deletion of 610 nucleotides in the smaller mRNA was verified by reverse transcription–PCR and sequencing. Genomic PCR showed the new sequence to be an extension of exon 56 of the COL17A1 gene which suggests that the second mRNA is generated by differential splicing. In normal keratinocytes the level of the smaller transcript was 5–15% of that of the larger transcript whereas in a squamous cell carcinoma cell line this ratio was reversed, the smaller mRNA being three times more abundant than the larger mRNA. The biological significance of this newly identified transcript in protein synthesis and tissue expression or in cell differentiation, proliferation or adhesion is as yet unknown.

Association analysis fails to confirm Xq27 as candidate region for a testicular germ cell tumour susceptibility gene.

4579 Background: Testicular Germ Cell Tumours (TGCT) was found to be linked to the X chromosome. Families with at least one bilateral case appeared to be linked to a 2.7 Mb region on Xq27 (Rapley et al. Nat Genet. 2000 Feb;24(2):197–200). We tried to confirm this finding in a comprehensive association study with markers from this region. Methods: In 288 testicular cancer patients and 169 unaffected first-degree male family members, 12 microsatellite markers covering the candidate region were genotyped and matched the quality criteria to study association with Xq27 both by single locus and haplotype analysis (haplotype sharing statistics (HSS). Results: None of these 12 markers analyzed, or combinations, showed association with TGCT. Subgroup analyses of cases with bilateral TGCT (n=11), familiar TGCT (n=28) and cryptorchism (n=44) did also not reveal evidence for association with Xq27. Conclusions: We could not replicate the previously observed linkage of TGCT to Xq27 by association analysis. Our sample h...