Comprehensive analysis of the role of DNA repair gene polymorphisms on risk of glioma

Much of the variation in inherited risk of glioma is likely to be explained by combinations of common low risk variants. The established relationship between glioma risk and exposure to ionizing radiation led us to examine whether variants in the DNA repair genes contribute to disease susceptibility. We evaluated 1127 haplotype-tagging single-nucleotide polymorphisms (SNPs) supplemented with 388 putative functional SNPs to capture most of the common variation in 136 DNA repair genes, in five unique case-control series from four different countries (1013 cases, 1016 controls). We identified 16 SNPs associated with glioma risk at the 1% significance level. The highest association observed across the five independent case-control datasets involved rs243356, which maps to intron 3 of CHAF1A (trend odds ratio, 1.32; 95% confidence interval 1.14-1.54; P = 0.0002; false-positive report probability = 0.055, based on a prior probability of 0.01). Our results provide additional support for the hypothesis that low penetrance variants contribute to the risk of developing glioma and suggest that a genetic variant located in or around the CHAF1A gene contributes to disease risk.

Second primary tumors following a diagnosis of meningioma in Sweden, 1958-1997

This study quantifies the risk of second primary tumors following a diagnosis of meningioma. 12,012 meningiomas and 926 second primary cancers were identified (ICD7, path code 461) between 1958 and 1997 using Swedish Cancer Registry data. Standardized incidence ratios (SIRs) and exact 95% confidence intervals (CIs) were calculated. An elevated risk of any second primary cancer diagnosis (SIR = 1.2, 95% CI = 1.1-1.3) was observed. Elevated and statistically significant SIRs were observed for renal cancer (SIR = 1.6), melanoma (SIR = 1.7), thyroid cancer (SIR = 2.6) and brain tumors (SIR = 2.6). A consistent pattern of risk over time supports the evaluation of common risk factor profiles for renal, melanoma and thyroid cancers. Radiation exposures increase the risk of these rare tumors, so quantifying the cumulative and shared effects of environmental and treatment exposures is of further interest.

An international case-control study of glutathione transferase and functionally related polymorphisms and risk of primary adult brain tumors

BACKGROUND

Glutathione transferases (GST) detoxify environmental and endogenous compounds and levels of two polymorphic GST proteins, GSTM3 and GSTP1, are high in the brain. Previous studies of GSTM3 and GSTP1 polymorphisms and adult brain tumor risk have produced inconsistent results, whereas the GSTM3 -63 variant is newly identified and, therefore, has not yet been studied in this context. We therefore examined associations between GSTM3 -63, GSTM3 *A/*B, GSTP1 105, and GSTP1 114 variants and adult brain tumor risk and the interaction of the effects of these same polymorphisms with cigarette smoking. In addition, the enzymes NQO1 and CYP1A1 alter susceptibility to oxidative brain damage. Because there is less previous evidence for a role of NQO1, CYP1A1, GSTM1, and GSTT1 variants, we restricted analysis of these variants to a small preliminary study.

METHODS

We genotyped DNA collected for an international population-based case-control study of 725 glioma cases, 329 of which were glioblastoma cases, 546 meningioma cases and 1,612 controls. Study participants were residents of Sweden, southeast England, Denmark, and Finland.

RESULTS

We found no associations between the GSTM3, GSTP1, NQO1, CYP1A1, GSTM1, or GSTT1 polymorphisms and adult brain tumor risk with the possible exception of a weak association between the G-C (Val-Ala) GSTP1 105/114 haplotype and glioma [odds ratio (OR), 0.73; 95% confidence interval (95% CI), 0.54, 0.99], nor was there an interaction between the effects of the GSTM3 or GSTP1 polymorphisms and cigarette smoking.

CONCLUSIONS

Overall, we observed no strong evidence for an association between GST or related enzyme polymorphisms and adult brain tumor risk.

Estrogen receptor beta polymorphism is associated with prostate cancer risk

PURPOSE

After cloning of the second estrogen receptor, estrogen receptor beta (ERbeta) in 1996, increasing evidence of its importance in prostate cancer development has been obtained. ERbeta is thought to exert an antiproliferative and proapoptotic effect. We examined whether sequence variants in the ERbeta gene are associated with prostate cancer risk.

EXPERIMENTAL DESIGN

We conducted a large population-based case-control study (CAncer Prostate in Sweden, CAPS) consisting of 1,415 incident cases of prostate cancer and 801 controls. We evaluated 28 single nucleotide polymorphisms (SNP) spanning the entire ERbeta gene from the promoter to the 3'-untranslated region in 94 subjects of the control group. From this, we constructed gene-specific haplotypes and selected four haplotype-tagging SNPs (htSNP: rs2987983, rs1887994, rs1256040, and rs1256062). These four htSNPs were then genotyped in the total study population of 2,216 subjects.

RESULTS

There was a statistically significant difference in allele frequency between cases and controls for one of the typed htSNPs (rs2987983), 27% in cases and 24% in controls (P = 0.03). Unconditional logistics regression showed an odds ratio of 1.22 (95% confidence interval, 1.02-1.46) for men carrying the variant allele TC or CC versus the wild-type TT, and an odds ratio of 1.33 (95% confidence interval, 1.08-1.64) for localized cancer. No association of prostate cancer risk with any of the other SNPs or with any haplotypes were seen.

CONCLUSION

We found an association with a SNP located in the promoter region of the ERbeta gene and risk of developing prostate cancer. The biological significance of this finding is unclear, but it supports the hypothesis that sequence variation in the promoter region of ERbeta is of importance for risk of prostate cancer.

Breast Cancer as a Second Primary in Patients With Prostate Cancer—Estrogen Treatment or Association With Family History of Cancer?

PURPOSE

In a large population based study we reported an increased risk of male breast cancer after prostate cancer. In the current study we performed a comprehensive investigation of whether treatment for prostate cancer and/or family history is responsible for the excess risk.

MATERIALS AND METHODS

This study had 2 parts. 1) We performed a nested case-control study in 41 men who had previously been identified with first prostate cancer, followed by male breast cancer and in 81 matched controls with prostate cancer only. The medical records of these men were retrieved and clinical data such as stage, grade and treatment were extracted. 2) We also performed a family study including relatives of men with a diagnosis of prostate as well as breast cancer, irrespective of which was first. The 878 relatives were identified through parish offices and linked to the Swedish Cancer Registry to evaluate the occurrence of breast, prostate and other cancers and calculate if there were any excess risks for different cancers.

RESULTS

Cases with prostate plus breast cancer received estrogen treatment more often than controls with prostate cancer only (p = 0.03). The period of estrogen treatment was longer in the cases, although it was not statistically significant. Mean time from prostate cancer diagnosis to breast cancer diagnosis was 47.6 months. Cases and controls did not differ in grade or stage. In the family study an increased risk of prostate cancer was found in relatives (SIR 2.14, 95% CI 1.09 to 3.18). For other cancers no significantly increased risks were found. In 2 families pedigree analysis using the BRCAPRO program (http://www3.utsouthwestern.edu/cancergene/) revealed an estimated 100% and 49% probability in families 1 and 2, respectively, that the proband was a BRCA2 carrier.

CONCLUSIONS

Our data suggest that most of the increased risk of breast cancer following prostate cancer can be explained by estrogen treatment. However, in a small number of men with prostate as well as breast cancer pedigree analysis suggests that BRCA2 mutation might be the underlying cause.

A road map for efficient and reliable human genome epidemiology

Networks of investigators have begun sharing best practices, tools and methods for analysis of associations between genetic variation and common diseases. A Network of Investigator Networks has been set up to drive the process, sponsored by the Human Genome Epidemiology Network. A workshop is planned to develop consensus guidelines for reporting results of genetic association studies. Published literature databases will be integrated, and unpublished data, including 'negative' studies, will be captured by online journals and through investigator networks. Systematic reviews will be expanded to include more meta-analyses of individual-level data and prospective meta-analyses. Field synopses will offer regularly updated overviews.

Homozygosity mapping of familial glioma in Northern Sweden

About 5% of glioma cases are familial. Most glioma families are not ascribed to the well-known glioma predisposing syndromes. One segregation analysis has supported an autosomal recessive gene in glioma families, which could be studied by homozygosity mapping. The ancestors of seven glioma families from the northern region of Sweden were traced through genealogical databases. A common ancestor and inbreeding were traced to give support to an autosomal recessive gene. Homozygosity mapping was performed with a genome-wide scan of 811 markers with linkage calculations. The families were geographically mapped to see if familial glioma was more common in northern compared with southern Sweden. Three of the seven families were remotely related. Homozygosity mapping did not reveal any allele homozygous for all three families. However, there was a geographical clustering of glioma families in the northern region of Sweden. A non-parametric analysis showed an allele-sharing LOD score of 1.05 for marker D1S196 on chromosome 1q23. Genealogical studies linking glioma families might be a tool for linkage in a small set of families. This study did not support an autosomal recessive gene, implicating a low penetrant dominant gene as a possible explanation to the glioma family clustering.

Polymorphisms associated with asthma are inversely related to glioblastoma multiforme

A reduced risk of primary malignant adult brain tumors is observed among people reporting asthma, hay fever, and other allergic conditions; however, findings may be attributed to prediagnostic effects of tumors or recall bias. To determine whether asthma and allergic condition polymorphisms are inversely related to glioblastoma multiforme (GBM) risk, we conducted a population-based case-control study of 111 GBM patients and 422 controls. We identified five single nucleotide polymorphisms on three genes previously associated with asthma [interleukin (IL)-4RA, IL-13, ADAM33] and one gene associated with inflammation (cyclooxygenase-2). Confirming previous literature, we found that self-reported asthma, eczema, and fever are inversely related to GBM [e.g., asthma odds ratio (OR), 0.64; 95% confidence interval (CI), 0.33-1.25]. In addition, IL-4RA Ser478Pro TC, CC, and IL-4RA Gln551Arg AG, AA are positively associated with GBM (OR, 1.64; 95% CI, 1.05-2.55; 1.61; 95% CI, 1.05-2.47), whereas IL-13 -1,112 CT, TT is negatively associated with GBM (0.56; 95% CI, 0.33-0.96). Each of these polymorphism-GBM associations is in the opposite direction of a corresponding polymorphism-asthma association, consistent with previous findings that self-reported asthmatics and people with allergic conditions are less likely to have GBM than are people who do not report these conditions. Because we used germ line polymorphisms as biomarkers of susceptibility to asthma and allergic conditions, our results cannot be attributed to recall bias or effects of GBM on the immune system. However, our findings are also consistent with associations between IL-4RA, IL-13, and GBM that are independent of their role in allergic conditions.

p53 Genotypes and Risk of Glioma and Meningioma

Brain tumors have previously been associated with the Li-Fraumeni syndrome that often is caused by p53 germ line mutations. Therefore, we investigated if polymorphisms of p53 were associated with an increased risk of meningioma and glioma and integrated the polymorphism analyses with detailed information on family history of cancer. In a population-based case-control study, DNA was extracted from 205 glioma and 164 meningioma cases identified during 2000 to 2002 in Sweden and from 374 controls selected randomly from the general population, stratified on age, sex, and geographic region. The Swedish Cancer Registry confirmed a cancer in family members in 86% of cases and controls that reported a family history of cancer. p53 single nucleotide polymorphism (SNP) analyses were done on three SNPs from the promoter region, codon 72 in exon 4, and intron 6. Overall, no associations were found for any of the SNPs. Analyses of the combinations of the three SNPs were also done. The CC-CG-CC-specific polymorphism combination was associated with an odds ratio (OR) of 1.36 [95% confidence interval (95% CI), 0.68-2.72] for glioma and 1.36 (0.64-2.88) for meningioma. When restricting the analyses to cases and controls with a positive family history of cancer, the corresponding results were OR of 3.62 (95% CI, 1.05-12.48) for glioma and 5.69 (1.81-17.96) for meningioma. This study is novel in suggesting an increased risk of brain tumors when the analysis is restricted to those with a history of cancer in the family. However, we cannot rule out the possibility that these results are due to chance.

Prior hospitalization for epilepsy, diabetes, and stroke and subsequent glioma and meningioma risk

We conducted a case-control study to evaluate the preclinical association between epilepsy, diabetes, and stroke and primary adult brain tumors. We first identified all 1,501 low-grade glioma, 4,587 high-grade glioma (HGG), and 4,193 meningioma cases reported to the Swedish Cancer Registry from 1987 to 1999. Next, controls (137,485) were randomly selected from the continuously updated Swedish Population Registry and matched to cases diagnosed that year on age and sex. Finally, cases and controls were linked to the Swedish Hospital Discharge Registry (1969-1999). We found that > or =8 years before HGG diagnosis (or control reference year) there was an elevated risk of HGG among people discharged with epilepsy [odds ratio (OR), 3.01; 95% confidence interval (95% CI), 1.73-5.22]. Two to 3 years before HGG diagnosis, this risk increased (OR, 5.33; 95% CI, 3.58-7.93) and was especially strong among people ages <55 years (OR, 13.49; 95% CI, 6.99-25.94). During this 2- to 3-year prediagnostic period, we also found an increased risk of HGG among people discharged with meningitis (OR, 3.02; 95% CI, 1.06-8.59) or viral encephalitis (OR, 12.64; 95% CI, 2.24-71.24). Results are similar for glioblastoma multiforme, low-grade glioma, and meningioma. In contrast, risk of HGG among people discharged with diabetes or stroke does not increase until year of brain tumor diagnosis. The occurrence of excess epilepsy > or =8 years before HGG diagnosis suggests a relatively long preclinical phase, but excess diabetes or stroke appear late in HGG development.

Increased copy number at 3p14 in breast cancer

INTRODUCTION

The present study was conducted to investigate if chromosome band 3p14 is of any pathogenic significance in the malignant process of breast cancer. Genetic studies have implicated a tumour suppressor gene on chromosome arm 3p and we have proposed LRIG1 at 3p14 as a candidate tumour suppressor. The LRIG1 gene encodes an integral membrane protein that counteracts signalling by receptor tyrosine kinases belonging to the ERBB family. LRIG1 mRNA and protein are expressed in many tissues, including breast tissue.

METHODS

In the present report we analysed the LRIG1 gene by fluorescence in situ hybridisation (FISH), LRIG1 mRNA by quantitative RT-PCR, and LRIG1 protein by western blot analysis. Two tumour series were analysed; one series consisted of 19 tumour samples collected between 1987 and 1995 and the other series consisted of 9 tumour samples with corresponding non-neoplastic breast tissues collected consecutively.

RESULTS

The LRIG1 gene showed increased copy number in 11 out of 28 tumours (39%) and only one tumour showed a deletion at this locus. Increased LRIG1 copy number was associated with increased levels of LRIG1 mRNA (two of three tumours) and protein (four of four tumours) in the tumours compared to matched non-neoplastic breast tissue, as assessed by RT-PCR and western blot analysis.

CONCLUSION

The molecular function of LRIG1 as a negative regulator of ERBB receptors questions the biological significance of increased LRIG1 copy number in breast cancer. We propose that a common, but hitherto unrecognised, breast cancer linked gene is located within an amplicon containing the LRIG1 locus at 3p14.3.

Epidermal growth factor receptor family (EGFR, ErbB2-4) in gliomas and meningiomas

Overexpression of epidermal growth factor receptor (EGFR, ErbB1) correlates with enhanced malignant potential of many human tumor types including glioblastoma multiforme. The significance of EGFR expression in meningiomas is, however, unclear. Reports regarding the other EGFR family members, ErbB2-4, in brain tumors are sparse. In this study, the expression of the EGFR family members was analyzed in relation to various parameters for the clinical importance of these receptors in 44 gliomas and 26 meningiomas. In gliomas, quantitative real-time reverse transcription (RT)-PCR revealed the highest EGFR mRNA expression in high-grade gliomas, while ErbB2 and ErbB3 mRNA were detected only in a few high-grade gliomas. In contrast, ErbB4 expression was most pronounced in low-grade gliomas. Immunohistochemistry showed significantly higher EGFR protein expression in high-grade gliomas compared to low-grade gliomas (P= 0.004). ErbB2 protein expression was mainly seen in high-grade gliomas. ErbB3 protein expression was low in all gliomas analyzed. ErbB4 protein expression was significantly higher in low-grade gliomas than in high-grade gliomas (P= 0.007). In meningiomas, quantitative real-time RT-PCR revealed expression of EGFR, ErbB2, and ErbB4 mRNA in the majority of the tumors. ErbB3 was detected in only one of the meningiomas analyzed. Immunohistochemistry demonstrated high ErbB2 protein expression in meningiomas. An intriguing observation in astrocytomas and oligodendrogliomas grade II, was a significantly decreased overall survival for patients with high EGFR protein expression (P= 0.04). The high ErbB4 expression in low-grade compared to high-grade gliomas might suggest that ErbB4 acts as a suppressor of malignant transformation in brain tumors, which is in line with previous studies in other tumor types.

Heterogeneity in the expression of markers for drug resistance in brain tumors

Brain tumors, in general, display a multidrug-resistant phenotype. This study evaluated the immunohistochemical expression and distribution of P-glycoprotein (Pgp), multidrug resistance protein (MRP1), lung resistance protein (LRP) and O6 methylguanine-DNA methyltransferase (MGMT) in low- and high-grade astrocytoma, oligodendroglioma and in different subgroups of meningioma. The results revealed a marked heterogeneity in the expression and distribution among the analyzed tumors. In astrocytoma and oligodendroglioma, Pgp and MRP1 were observed in the capillary endothelium and in scattered tumor cells, whereas LRP occurred only in tumor cells. A pronounced expression of MGMT was found independent of the histopathological grade. An enhanced expression of MRP1 and LRP in astrocytoma and oligodendroglioma were more often evident in older patients (> 50 years). Survival analysis suggested a markedly decreased overall survival for patients suffering from low-grade glioma overexpressing Pgp. In meningioma, a heterogeneous expression of Pgp, MRP1, LRP and MGMT was seen with the most prominent staining localized to the capillary endothelium. Pgp was significantly more often overexpressed (p < 0.05) in transitional compared to meningothelial meningioma. The marked heterogeneity in the expression suggests that analysis of these factors can be of importance in the selection of individualized chemotherapy, regardless of tumor type.

Familial brain tumours-genetics or environment? A nationwide cohort study of cancer risk in spouses and first-degree relatives of brain tumour patients

Our study investigated whether the familial aggregation of glioma is due to environmental or genetic effects and it investigated and compared the risk to spouses and first-degree relatives (FDR) of patients with primary brain tumours (PBT) for developing both PBT and the risk for other types of cancer. All PBT patients identified in Sweden from 1958-97 in The Swedish Cancer Registry (SCR) were linked to the nationwide Swedish Family Database, including persons in Sweden born from 1932-97. The cohorts of spouses and FDR were linked to the SCR to identify observed cases of PBT and other cancer. Standardised incidence ratios (SIR) were calculated using the incidence rates from SCR as the reference. We found that there were no increased risks for any specific type of PBT in the cohort of spouses. In the FDR cohort, generally the risk for a PBT was significantly increased by 2 to 3 times for the same histopathology as the probands. Spouses of PBT patients had an increased risk of skin cancer. We conclude that FDR, not spouses, have a significantly increased risk, which indicates a genetic origin of the familial aggregation of brain tumours.

Reproductive factors have low impact on the risk of different primary brain tumours in offspring

OBJECTIVES

The aim of our study was to investigate whether reproductive factors influence the risk of primary brain tumours (PBT) in offspring.

METHODS

Data on all deliveries in two Swedish counties from 1955 to 1990 were extracted from two birth registries. The follow-up period closed at the end of 1994, with subjects followed up to early middle age. Incidence rates of malignancy for 1958-1994 were obtained from the Swedish Cancer Registry. Standardised incidence ratios (SIR) and relative risks were calculated for astrocytomas, primitive neuroectodermal tumour, ependymoma and meningiomas in offspring.

RESULTS

Few associations were detected. High birth weight indicated an increased risk for astrocytomas grade I and II for all primary brain tumours, and the risk was close to significance for astrocytomas grade I-II (SIR = 3.64; CI = 0.98-9.31). For children under 15 years of age the risk for astrocytomas grade I and II was further increased (SIR = 4.44; CI = 1.19-11.38).

CONCLUSIONS

A consistent pattern of non-association indicated a low impact of intrauterine environment on the future development of primary brain tumours in offspring up to early middle age.

Second primary cancers in men with prostate cancer: an increased risk of male breast cancer

PURPOSE

Evaluation of second primary cancers provides valuable insight about etiology and shared risk factors. Studies of second primary cancers following prostate cancer conclude that overall risk of second primary cancers decreases. However, risk of bladder cancer and kidney cancer increases. We examine the risk of common and rare second primary cancers following prostate cancer in a large population based cohort to identify possible common etiological factors.

MATERIALS AND METHODS

All prostate cancer cases in the Swedish Cancer Registry (135, 713) from 1958 to the end of 1996 constituted the study base. Risk (standardized incidence ratio) of second primary cancers was calculated as the ratio between observed and expected number of cancers. We used 2-tailed 95% confidence intervals (CI) to test significance.

RESULTS

An overall increased risk (standardized incidence ratio 1.17, 95% CI 1.15-1.19) of second primary cancers was found but was only seen in the first 6 months of followup (ratio 3.45, 3.32-3.57). The most interesting finding was an increased risk (ratio 2.01, 95% CI 1.44-2.74) of male breast cancer. Other tumor sites with increased risk were the small intestine (standardized incidence ratio 1.39, 95% CI 1.09-1.51), skin melanoma (ratio 1.33, 95% CI 1.16-1.51) and endocrine tumors (ratio 1.41, 95% CI 1.13-1.74).

CONCLUSIONS

A small but increased risk of second primary cancers following prostate cancer was found, most likely due to increased surveillance during the first 6 months after diagnosis. However, following prostate cancer there is an increased risk of endocrine related second primary cancers such as male breast cancer and carcinoids in the small intestine. To our knowledge these associations have not been reported previously, and they warrant more study.

Does a low frequency of P53 and Pgp expression in familial glioma compared to sporadic controls indicate biological differences?

BACKGROUND

A three-fold increased risk for glioma among first degree relatives (FDR) to glioma patients has previously been shown. This study compared familial cases with sporadic controls of glioma to see if phenotypic differences could be detected. Different pathways to tumour growth and progression were investigated including cell cycle regulating genes (p53) and growth factors (epidermal growth factor receptor, EGFR), angiogenesis (vascular endothelial growth factor, VEGF and microvessel density, MVD), pathways of detoxification (glutathione-S-transferase, GST pi) and multidrug resistance (P-glycoprotein, Pgp).

MATERIALS AND METHODS

Thirty-seven cases of familial gliomas, identified in a population-based study, were compared to 58 sporadic glioma controls chosen with a negative family history of glioma. The immunohistochemistry was performed with standard procedures using the LABSA kit (Zymed lab).

RESULTS

Familial cases had significantly more frequent p53- and Pgp-negative tumours, also when correcting for age, sex and histopathology. However, Pgp was no longer significant after correcting for p53 status indicating a correlation between Pgp and p53. A significant difference between VEGF-negative to VEGF-positive tumours (low- or high-grade) was shown, but it was no longer significant when correcting for p53 status.

CONCLUSION

Our study investigated phenotypic differences of familial glioma compared to sporadic control. Our finding of a distinct pattern of increased p53- and Pgp-negativity among cases warrants further investigation.

Different aetiology of familial low-grade and high-grade glioma? A nationwide cohort study of familial glioma

An increased risk for first-degree relatives (FDR) of glioma patients has previously been observed. The novel objective of this study was to investigate differences in familial risk among FDR of low-grade glioma (LGG) and high-grade glioma (HGG) cases, respectively. Two cohorts were constructed, one from 15,321 FDR of LGG cases and the other from 26,635 FDR of HGG cases calculating standardised incidence ratios (SIR). The risk for LGG among FDR of LGG cases was significantly increased, SIR 3.65 (95% CI 2.31-5.47). The risk was even higher in the cohort of siblings, SIR 7.00 (95% CI 3.35-12.87), and especially in the younger siblings (<40 years), SIR 9.01 (95% CI 4.31-16.57). When calculating the risk for HGG in the LGG cohort and the risk for HGG in the HGG cohort, there was a generally twofold increased risk, but no trends of increased risk in relatives of younger probands. Two different methods calculating familial risk displayed similar results. LGG families apparently have features manifesting a distinct pedigree pattern with sibpairs affected at a young age. These families could provide new insights into the aetiology of glioma.

Microsatellite instability, PTEN and p53 germline mutations in glioma families

Rare inherited syndromes that to some extent explain familial glioma include Turcot's syndrome, Li-Fraumeni syndrome and neurofibromatosis types I and II. The majority of families with glioma do not meet the clinical criteria for any of these syndromes. In order to study the genetic origin of familial glioma, tumour DNA (n = 35) or blood samples (n = 8) were collected from 25 families. The glioma tumours were tested for microsatellite instability (MSI) with two markers, BAT25 and BAT26, since glioma is associated with hereditary non-polyposis colon cancer (HNPCC) in Turcot's syndrome. Furthermore, p53 was screened from blood DNA (exons 2-11) with temporal temperature gradient electrophoresis (TTGE) since germline mutations in p53 are seen in Li-Fraumeni syndrome. In gliomas, there is a wide variety of somatic mutations, such as, for instance, in p53, the epidermal growth factor receptor (EGFR) and p16. The tumour suppressor gene PTEN is also often somatically mutated in glioma, therefore it is attractive as a candidate gene for germline mutations in familial glioma. Blood DNA was directly sequenced for mutations in PTEN exons 1-9. The analysis showed that no mutations were found in either of the studied tumour suppressor genes, and no MSI-positive tumours were found. A common polymorphism in p53 at codon 72 (arginine/proline) was found in 6/8 of the patients. Apparently, mutation in the tested tumour suppressor genes or DNA mismatch repair genes does not explain the familial glioma observed in these families.

Genetic epidemiology of glioma

The present study performed a segregation analysis of a cohort of first-degree relatives (FDR) of glioma patients. The families with two or more gliomas were also expanded to determine if any more gliomas could be detected, and if any other types of cancers were associated. These glioma-prone families (n = 24/432) were extended to include first-, second- and third-degree relatives (n = 807) and a cohort was assembled, the standardized incidence risk for other types of cancer calculated and the pedigrees investigated for a possible mode of inheritance. A segregation analysis of the 2141 FDR in 297 families, performed using the Pointer software, did not clearly reject a multifactorial model chi(2)(3) = 6.13, P< 0.2. However, when letting all parameters be free, the recessive model provided the best fit. In the extended families, no increased risk of other types of cancer was found. This population-based study proposes that familial glioma occurs in about 5% of all glioma cases and that 1% have a possible autosomal dominant inheritance. This first segregation analysis performed in familial glioma must be cautiously interpreted, but an autosomal recessive gene provided the best fit, which could possibly explain 2% of all glioma cases.

Wegener granulomatosis in children and young adults. A case study of ten patients

This retrospective study reports seven children and three young adults (aged 11-30 years) who suffered from Wegener granulomatosis. Nine represent consecutive patients admitted to the Division of Nephrology over a period of 23 years. All patients had respiratory tract symptoms and renal involvement on admission. In several patients infiltrates on chest X-ray developed within 2 weeks of onset of symptoms. All patients survived. The median observation period was 9 years (range 13 months to 23 years). One patient progressed to end-stage renal disease. Nine patients initially received cyclophosphamide and steroids. After a median period of 9 months (range 6-31 months) the cyclophosphamide was replaced by azathioprine. Relapses occurred after a median of 28 months (range 4-120 months) in 80% of patients, in six of the eight patients causing a definite decrease in kidney function. We believe that early diagnosis and initiation of therapy reduce the extent of organ damage. Since relapses are frequent, these patients should be evaluated frequently.