Metastatic osteosarcoma tumor thrombus in a Cavalier King Charles Spaniel presenting with dyspnea.

A six-year-seven-month-old female neutered Cavalier King Charles Spaniel was referred for the investigation of progressive dyspnea and hyphema in the right eye with secondary glaucoma. Previous medical history included a high-grade soft tissue spindle cell sarcoma removed from the cranial sternal region one year before. On presentation at the referral hospital, the dog was tachypneic and dyspneic. The heart rhythm was regular and there was a soft left-sided systolic murmur. Echocardiography identified the presence of a mass significantly occluding left heart inflow, with no other lesions identified. Thoracic radiographs documented a localized alveolar pattern within the left caudal lung lobe. The size of the heart and pulmonary vessels were within normal limits, indicating a non-cardiogenic alveolar pattern. Given the clinical presentation of dyspnea and high index of suspicion of intra-cardiac neoplasia, the dog was considered to have a grave prognosis and therefore euthanized. Post-mortem gross and histopathologic examination revealed the presence of a metastatic osteosarcoma tumor thrombus in the left atrium and pulmonary vein, metastatic osteosarcoma infiltrating the myocardium, lungs, the uveal tract of the right eye, and both adrenal glands. Whitney grade II myxomatous changes were noted on the mitral and tricuspid valve leaflets. This report describes an unusual intra-cardiac tumor thrombus in a dog presenting with dyspnea. Cavalier King Charles Spaniels presenting with dyspnea often raise suspicion for myxomatous mitral valve disease. However, as demonstrated in this case, other more unusual causes of dyspnea should also be considered in the absence of classic clinical findings.

Germline ATM variants predispose to melanoma: a joint analysis across the GenoMEL and MelaNostrum consortia.

PURPOSE: Ataxia-Telangiectasia Mutated (ATM) has been implicated in the risk of several cancers, but establishing a causal relationship is often challenging. Although ATM single-nucleotide polymorphisms have been linked to melanoma, few functional alleles have been identified. Therefore, ATM impact on melanoma predisposition is unclear. METHODS: From 22 American, Australian, and European sites, we collected 2,104 familial, multiple primary (MPM), and sporadic melanoma cases who underwent ATM genotyping via panel, exome, or genome sequencing, and compared the allele frequency (AF) of selected ATM variants classified as loss-of-function (LOF) and variants of uncertain significance (VUS) between this cohort and the gnomAD non-Finnish European (NFE) data set. RESULTS: LOF variants were more represented in our study cohort than in gnomAD NFE, both in all (AF = 0.005 and 0.002, OR = 2.6, 95% CI = 1.56-4.11, p < 0.01), and familial + MPM cases (AF = 0.0054 and 0.002, OR = 2.97, p < 0.01). Similarly, VUS were enriched in all (AF = 0.046 and 0.033, OR = 1.41, 95% CI = 1.6-5.09, p < 0.01) and familial + MPM cases (AF = 0.053 and 0.033, OR = 1.63, p < 0.01). In a case-control comparison of two centers that provided 1,446 controls, LOF and VUS were enriched in familial + MPM cases (p = 0.027, p = 0.018). CONCLUSION: This study, describing the largest multicenter melanoma cohort investigated for ATM germline variants, supports the role of ATM as a melanoma predisposition gene, with LOF variants suggesting a moderate-risk.

The Impact of the Storm Emma on Irish Emergency Department Attendances.

Aim The impact of severe weather events on Irish EDs has not yet been characterised. The aim of this study was to examine the impact of Storm Emma on the attendance patterns to an Irish ED. Methods Data was collected for 64hrs prior to the red alert (Pre-Red), 38hrs of the red alert (Red) and for the 256 hrs (10 days) post the red alert (Post-Red) during Storm Emma. A Comparison was made with the same time periods in 2017. Results There was a statistically significant decrease in attendance during the Red period in 2018, compared with 2017 (119 vs. 234, p<0.001), with a rebound surge in attendances in the Post-Red period (1,861 vs 1,578, p<0.001). Mean patient experience times were significantly longer in the Post-Red period in 2018 (9.5+/-9.5hrs vs 7.9+/-8.2hrs, p<0.001). Conclusion This study has detailed the impact of a severe weather event on an Irish ED and will help inform preparedness for the future.

Intergenic disease-associated regions are abundant in novel transcripts.

BACKGROUND: Genotyping of large populations through genome-wide association studies (GWAS) has successfully identified many genomic variants associated with traits or disease risk. Unexpectedly, a large proportion of GWAS single nucleotide polymorphisms (SNPs) and associated haplotype blocks are in intronic and intergenic regions, hindering their functional evaluation. While some of these risk-susceptibility regions encompass cis-regulatory sites, their transcriptional potential has never been systematically explored. RESULTS: To detect rare tissue-specific expression, we employed the transcript-enrichment method CaptureSeq on 21 human tissues to identify 1775 multi-exonic transcripts from 561 intronic and intergenic haploblocks associated with 392 traits and diseases, covering 73.9 Mb (2.2%) of the human genome. We show that a large proportion (85%) of disease-associated haploblocks express novel multi-exonic non-coding transcripts that are tissue-specific and enriched for GWAS SNPs as well as epigenetic markers of active transcription and enhancer activity. Similarly, we captured transcriptomes from 13 melanomas, targeting nine melanoma-associated haploblocks, and characterized 31 novel melanoma-specific transcripts that include fusion proteins, novel exons and non-coding RNAs, one-third of which showed allelically imbalanced expression. CONCLUSIONS: This resource of previously unreported transcripts in disease-associated regions ( http://gwas-captureseq.dingerlab.org ) should provide an important starting point for the translational community in search of novel biomarkers, disease mechanisms, and drug targets.

Melanocyte transformation requires complete loss of all pocket protein function via a mechanism that mitigates the need for MAPK pathway activation.

Deregulation of p16INK4A is a critical event in melanoma susceptibility and progression. It is generally assumed that the major effect of loss of p16 function is mediated through the CDK-cyclin pathway via its influence on the pocket protein (PP) pRb. However, there are also two other PPs, p107 and p130, which, when phosphorylated by CDK-cyclin complexes, play a role in permitting cell progression. Cohorts of mice carrying melanocyte-specific knockouts (KOs) of various combinations of the three PPs were generated. Mice null for pRb, p107, p130 or any combination of double mutants did not develop melanoma. Surprisingly, melanocyte-specific loss of all three PPs facilitated melanoma development (median age of onset 308 days, penetrance 40% at 1 year). Tumorigenesis was exacerbated by Trp53 co-deletion (median age of onset 275 days, penetrance 82% at 1 year), with cell culture studies indicating that this difference may result from the apoptotic role of Trp53. Melanomas in PP;Trp53-deficient mice lacked either Ras or Braf mutations, and hence developed in the absence of constitutive MAPK pathway activation. The lag period between induction of total PP or PP/Trp53 KO and melanoma development indicates that additional genetic or epigenetic alterations may account for neoplastic progression. However, exome sequencing of PP;Trp53 KO melanomas failed to reveal any additional recurrent driver mutations. Analysis of the putative mutation signature of the PP;Trp53 KO melanomas suggests that melanocytes are primed for transformation via a mutagenic mechanism involving an excess of T>G substitutions, but not involving a preponderance of C>T substitutions at CpG sites, which is the case for most spontaneous cancers not driven by a specific carcinogen. In sum, deregulation of all three PPs appears central to neoplastic progression for melanoma, and the customary reference to the p16INKA/CDK4/pRB pathway may no longer be accurate; all PPs are potentially critical targets of CDK-cyclins in melanoma.

Survival outcomes in patients with multiple primary melanomas.

BACKGROUND: A substantial number of melanoma patients will develop multiple primary melanomas (MPM). Currently, little is known about the impact of MPM on survival. OBJECTIVE: We aimed to determine whether melanoma survival is worse for patients with MPM compared to those with a single invasive primary melanoma (SPM). MATERIALS AND METHODS: A cohort study was conducted. Patients were sourced from an Australian population, with follow-up information collected retrospectively from registry data. Melanoma-specific survival analysis was performed to find associated variables after adjustment for known prognostic factors, using four different models, each selecting a different index melanoma lesion. RESULTS: 1068 stage I and II melanoma patients were followed up for a median of 24.4 years. MPM was found in 17.8% of the cohort (190 patients), more likely among males and older age groups. Other clinicopathological parameters were similar between the MPM and SPM (878 patients) cohorts. After adjustment for age, sex and Breslow thickness, MPM was a hazard for death from melanoma, across all models, reaching significance when considering the last invasive lesion as the index melanoma (HR = 2.76, P = 0.017). CONCLUSION: Patients with multiple invasive lesions seem more at risk of death from melanoma, independent of known prognostic factors.

A recurrent germline BAP1 mutation and extension of the BAP1 tumor predisposition spectrum to include basal cell carcinoma.

We report four previously undescribed families with germline BRCA1-associated protein-1 gene (BAP1) mutations and expand the clinical phenotype of this tumor syndrome. The tumor spectrum in these families is predominantly uveal malignant melanoma (UMM), cutaneous malignant melanoma (CMM) and mesothelioma, as previously reported for germline BAP1 mutations. However, mutation carriers from three new families, and one previously reported family, developed basal cell carcinoma (BCC), thus suggesting inclusion of BCC in the phenotypic spectrum of the BAP1 tumor syndrome. This notion is supported by the finding of loss of BAP1 protein expression by immunochemistry in two BCCs from individuals with germline BAP1 mutations and no loss of BAP1 staining in 53 of sporadic BCCs consistent with somatic mutations and loss of heterozygosity of the gene in the BCCs occurring in mutation carriers. Lastly, we identify the first reported recurrent mutation in BAP1 (p.R60X), which occurred in three families from two different continents. In two of the families, the mutation was inherited from a common founder but it arose independently in the third family.

Phase II study of single agent capecitabine in the treatment of metastatic non-pancreatic neuroendocrine tumours.

BACKGROUND: This study sought to determine the safety of single agent capecitabine, a pro-drug of 5FU, in patients with metastatic non-pancreatic neuroendocrine tumours (NETs). METHODS: Multicentre phase II, first-line study design. Oral capecitabine was administered on days 1-14 of 3-week cycles. RESULTS: Treatment was safe and well tolerated. Common toxicities were diarrhoea and fatigue. CONCLUSION: The study provides evidence to support the use of capecitabine as a substitute for infusional 5FU in the management of NETs.

Association of MC1R variants and host phenotypes with melanoma risk in CDKN2A mutation carriers: a GenoMEL study.

BACKGROUND: Carrying the cyclin-dependent kinase inhibitor 2A (CDKN2A) germline mutations is associated with a high risk for melanoma. Penetrance of CDKN2A mutations is modified by pigmentation characteristics, nevus phenotypes, and some variants of the melanocortin-1 receptor gene (MC1R), which is known to have a role in the pigmentation process. However, investigation of the associations of both MC1R variants and host phenotypes with melanoma risk has been limited. METHODS: We included 815 CDKN2A mutation carriers (473 affected, and 342 unaffected, with melanoma) from 186 families from 15 centers in Europe, North America, and Australia who participated in the Melanoma Genetics Consortium. In this family-based study, we assessed the associations of the four most frequent MC1R variants (V60L, V92M, R151C, and R160W) and the number of variants (1, ≥2 variants), alone or jointly with the host phenotypes (hair color, propensity to sunburn, and number of nevi), with melanoma risk in CDKN2A mutation carriers. These associations were estimated and tested using generalized estimating equations. All statistical tests were two-sided. RESULTS: Carrying any one of the four most frequent MC1R variants (V60L, V92M, R151C, R160W) in CDKN2A mutation carriers was associated with a statistically significantly increased risk for melanoma across all continents (1.24 × 10(-6) ≤ P ≤ .0007). A consistent pattern of increase in melanoma risk was also associated with increase in number of MC1R variants. The risk of melanoma associated with at least two MC1R variants was 2.6-fold higher than the risk associated with only one variant (odds ratio = 5.83 [95% confidence interval = 3.60 to 9.46] vs 2.25 [95% confidence interval = 1.44 to 3.52]; P(trend) = 1.86 × 10(-8)). The joint analysis of MC1R variants and host phenotypes showed statistically significant associations of melanoma risk, together with MC1R variants (.0001 ≤ P ≤ .04), hair color (.006 ≤ P ≤ .06), and number of nevi (6.9 × 10(-6) ≤ P ≤ .02). CONCLUSION: Results show that MC1R variants, hair color, and number of nevi were jointly associated with melanoma risk in CDKN2A mutation carriers. This joint association may have important consequences for risk assessments in familial settings.

Vascular changes in epilepsy: functional consequences and association with network plasticity in pilocarpine-induced experimental epilepsy.

Angiogenesis and blood-brain-barrier (BBB) damage have been proposed to contribute to epileptogenesis and/or ictogenesis in experimental and human epilepsy. We tested a hypothesis that after brain injury angiogenesis occurs in the most damaged hippocampal areas with the highest need of tissue repair, and associates with formation of epileptogenic neuronal networks. We induced status epilepticus (SE) with pilocarpine in adult rats, and investigated endothelial cell proliferation (BrdU and rat endothelial cell antigen-1 (RECA-1) double-labeling), vessel length (unbiased stereology), thrombocyte aggregation (thrombocyte immunostaining), neurodegeneration (Nissl staining), neurogenesis (doublecortin (DCX) immunohistochemistry), and mossy fiber sprouting (Timm staining) in the hippocampus at different time points post-SE. As functional measures we determined BBB leakage (quantified immunoglobulin G (IgG) immunostaining), and hippocampal blood volume (CBV) and flow (CBF) in vivo (magnetic resonance imaging, MRI). The total length of hippocampal blood vessels was decreased by 17% at 2 d after status epilepticus (SE) induced by pilocarpine in adult rats (P<0.05 as compared to controls) which was not accompanied by alterations in hippocampal blood volume (BV) and flow (BF). Number of proliferating endothelial cells peaked at 4 d post-SE and correlated with an increase in vessel length (r=0.900, P<0.05). Vessels length had recovered to control level or even higher at 2 wk post-SE, angiogenesis being most prominent in the CA3 (128% as compared to that in controls, P<0.05), and was associated with increased BV (178% as compared to that in controls, P<0.05). Enlargement of vessel diameter in the hippocampal fissure was associated with thrombocyte aggregation in distal capillaries. BBB was most leaky during the first 4 d post-SE and increased IgG extravasation was observed for 60 d. Our data show that magnitude of endothelial cell proliferation is not associated with severity of acute post-SE neurodegeneration or formation of abnormal neuronal network. This encourages identification of molecular targets that initiate and maintain specific aspects of tissue reorganization, including preservation and proliferation of endothelial cells to reduce the risk of epileptogenesis and enhance recovery after brain injury.

Prophylactic but not therapeutic activity of a monoclonal antibody that neutralizes the binding of VEGF-B to VEGFR-1 in a murine collagen-induced arthritis model.

OBJECTIVE: To assess the therapeutic potential of a mAb that neutralizes the binding of VEGF-B to VEGFR-1, to inhibit the pathogenesis of CIA in mice. METHODS: CIA was induced in C57BL6/J and DBA-1 mice by intradermal injection of chick collagen type II (CII) in adjuvant. A neutralizing VEGF-B mAb or an isotype control mAb was then administered by intraperitoneal injection twice weekly beginning either post CII booster injection but prior to or immediately following clinical disease diagnosis. RESULTS: Neutralizing VEGF-B mAb inhibited the development of CIA in C57BL6/J mice in a dose-dependent manner when administered following the CII booster injection, but prior to clinical disease diagnosis. This result was also confirmed in DBA-1 strain mice. In contrast, the neutralizing VEGF-B mAb had no measurable effect on disease severity or progression when treatment commenced from the day of clinical disease diagnosis. CONCLUSIONS: Treatment with an mAb that neutralizes the binding of VEGF-B to VEGFR-1 exhibits prophylactic but not therapeutic actions in a mouse model of RA. These data indicate that while VEGF-B/VEGFR-1 signalling is involved in the early development of arthritis it may not be required for maintenance or progression of established disease.

Leptin and the risk of Barrett's oesophagus.

BACKGROUND: Obesity is associated with increased risks of Barrett's oesophagus and oesophageal adenocarcinoma. Alterations in serum leptin and adiponectin, obesity-related cytokines, have been linked with several cancers and have been postulated as potential mediators of obesity-related carcinogenesis; however, the relationship with Barrett's oesophagus remains unexplored. METHODS: Serum leptin and adiponectin concentrations were measured on two subsets of participants within a case-control study conducted in Brisbane, Australia. Cases were people aged 18-79 years with histologically confirmed Barrett's oesophagus newly diagnosed between 2003 and 2006. Population controls, frequency matched by age and sex to cases, were randomly selected from the electoral roll. Phenotype and medical history data were collected through structured, self-completed questionnaires. Odds ratios (OR) and 95% CI were calculated using multivariable logistic regression analysis. RESULTS: In the pilot analysis (51 cases, 67 controls) risks of Barrett's oesophagus were highest among those in the highest quartile of serum leptin (OR 4.6, 95% CI 0.6 to 33.4). No association was seen with adiponectin. In the leptin validation study (306 cases, 309 controls), there was a significant threefold increased risk of Barrett's oesophagus among men in the highest quartile of serum leptin (OR 3.3, 95% CI 1.7 to 6.6) and this persisted after further adjustment for symptoms of gastro-oesophageal reflux (OR 2.4, 95% CI 1.1 to 5.2). In contrast, the risk of Barrett's oesophagus among women decreased with increasing serum leptin concentrations. CONCLUSIONS: High serum leptin is associated with an increased risk of Barrett's oesophagus among men but not women. This association is not explained simply by higher body mass or gastro-oesophageal reflux among cases. The mechanism remains to be determined.

Gene expression of lung squamous cell carcinoma reflects mode of lymph node involvement.

Tumour, node, metastasis staging is essential for lung cancer management. However, similarly staged cancers may have markedly different prognoses, indicating that stage cannot completely explain tumour behaviour. While ipsilateral hilar node involvement is designated N1, the current authors hypothesised that primary tumours involving nodes by direct extension are biologically distinct from those involving nodes through lymphatic metastasis. Microarrays were used to investigate the gene expression profiles of 59 primary lung squamous cell carcinomas, comparing N0 tumours (n = 35), N1 tumours by direct extension (N1d; n = 8), and N1/N2 tumours by lymphatic metastasis (N1/N2m; n = 16). Hierarchical clustering using 125 genes differentially expressed between N0 and N1/N2m tumours found N1d tumours clustered with N0 tumours. Class prediction modelling found the expression profiles of all eight N1d tumours were more similar to N0 than to N1/N2m tumours. The present study demonstrates for the first time that N1 tumours directly invading hilar nodes are genomically different to those that metastasise via lymphatics. Independent reports suggest that tumours with direct, rather than metastatic node involvement have better outcomes. Consequently, the data suggest that there is a need to re-evaluate the N1 staging definition in lung cancer. This is relevant for prognosis prediction and also for clinical management, particularly in selecting those patients most likely to benefit from adjuvant chemotherapy.

Expression profiling in monozygotic twins discordant for bipolar disorder reveals dysregulation of the WNT signalling pathway.

To identify genes dysregulated in bipolar disorder (BD1), we carried out global gene expression profiling using whole-genome microarrays. To minimize genetic variation in gene expression levels between cases and controls, we compared expression profiles in lymphoblastoid cell lines from monozygotic twin pairs discordant for the disease. We identified 82 genes that were differentially expressed by >or=1.3-fold in three BD1 cases compared to their co-twins, and which were statistically (P

Lack of augmentation of tumor spectrum or severity in dual heterozygous Men1 and Rb1 knockout mice.

To identify possible genetic interactions between the mechanisms of tumor suppression of menin and pRb, we intercrossed mice with targeted deletions of Men1 and Rb1, and compared tumor development in cohorts of animals carrying single or dual mutations of these tumor-suppressor genes. In mice lacking one copy of Men1, pancreatic islet and anterior pituitary adenomas are common. In animals lacking one copy of Rb1, intermediate pituitary and thyroid tumors occur at high frequency, with less frequent development of pancreatic islet hyperplasia and parathyroid lesions. In mice heterozygous for both Men1 and Rb1, pancreatic hyperplasia and tumors of the intermediate pituitary and thyroid occurred at high frequency. Serum measurements of calcium and glucose did not vary significantly between genotypic groups. Loss of heterozygosity at the Rb1 locus was common in pituitary and thyroid tumors, whereas loss of menin was observed in pancreatic and parathyroid lesions. The tumor spectrum in the double heterozygotes was a combination of pathologies seen in each of the individual heterozygotes, without decrease in age of onset, indicating independent, non-additive effects of the two mutations. Together with the lack of increased tumor spectrum, this suggests that menin and pRb function in a common pathway of tumor suppression.

Mutation of the tumour suppressor p33ING1b is rare in melanoma.

BACKGROUND: The p33ING1b gene is involved in the p53-dependent response to DNA damage following exposure to ultraviolet radiation, and has recently been reported to be mutated in 20% of melanoma tumours. OBJECTIVES: We sought to assess the p33ING1b mutation rate in our large panels of fresh melanomas and melanoma cell lines. METHODS: We screened 83 primary melanomas and 55 melanoma cell lines for mutations in p33ING1b by single-strand conformational polymorphism analysis and by direct sequencing. RESULTS: In contrast to previous reports, we found no somatic p33ING1b mutations in our panel of melanomas. We found that some of the discrepancy between our results and previously published studies may be due to inadvertent amplification of the ING1 pseudogene (INGX), and/or contamination of some samples with murine Ing1. CONCLUSIONS: p33ING1b mutations in melanoma are rare. We have highlighted the importance of allele-specific primer design to avoid pseudogene amplification, and also the necessity to confirm the genetic identity and species of origin of individual cell lines. Further studies are needed to clarify the possible role of p33ING1b in melanoma tumorigenesis.

Identification of the semaphorin receptor PLXNA2 as a candidate for susceptibility to schizophrenia.

The discovery of genetic factors that contribute to schizophrenia susceptibility is a key challenge in understanding the etiology of this disease. Here, we report the identification of a novel schizophrenia candidate gene on chromosome 1q32, plexin A2 (PLXNA2), in a genome-wide association study using 320 patients with schizophrenia of European descent and 325 matched controls. Over 25,000 single-nucleotide polymorphisms (SNPs) located within approximately 14,000 genes were tested. Out of 62 markers found to be associated with disease status, the most consistent finding was observed for a candidate locus on chromosome 1q32. The marker SNP rs752016 showed suggestive association with schizophrenia (odds ratio (OR) = 1.49, P = 0.006). This result was confirmed in an independent case-control sample of European Americans (combined OR = 1.38, P = 0.035) and similar genetic effects were observed in smaller subsets of Latin Americans (OR = 1.26) and Asian Americans (OR = 1.37). Supporting evidence was also obtained from two family-based collections, one of which reached statistical significance (OR = 2.2, P = 0.02). High-density SNP mapping showed that the region of association spans approximately 60 kb of the PLXNA2 gene. Eight out of 14 SNPs genotyped showed statistically significant differences between cases and controls. These results are in accordance with previous genetic findings that identified chromosome 1q32 as a candidate region for schizophrenia. PLXNA2 is a member of the transmembrane semaphorin receptor family that is involved in axonal guidance during development and may modulate neuronal plasticity and regeneration. The PLXNA2 ligand semaphorin 3A has been shown to be upregulated in the cerebellum of individuals with schizophrenia. These observations, together with the genetic results, make PLXNA2 a likely candidate for the 1q32 schizophrenia susceptibility locus.

Activation of the MAPK pathway is a common event in uveal melanomas although it rarely occurs through mutation of BRAF or RAS.

In contrast to cutaneous melanoma, there is no evidence that BRAF mutations are involved in the activation of the mitogen-activated protein kinase (MAPK) pathway in uveal melanoma, although there is increasing evidence that this pathway is activated frequently in the latter tumours. In this study, we performed mutation analysis of the RAS and BRAF genes in a panel of 11 uveal melanoma cell lines and 19 primary uveal melanoma tumours. In addition, Western blot and immunohistochemical analyses were performed on downstream members of the MAPK pathway in order to assess the contribution of each of these components. No mutations were found in any of the three RAS gene family members and only one cell line carried a BRAF mutation (V599E). Despite this, mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK), ERK and ELK were constitutively activated in all samples. These data suggest that activation of the MAPK pathway is commonly involved in the development of uveal melanoma, but occurs through a mechanism different to that of cutaneous melanoma.

A report of a national mutation testing service for the MEN1 gene: clinical presentations and implications for mutation testing.

INTRODUCTION: Mutation testing for the MEN1 gene is a useful method to diagnose and predict individuals who either have or will develop multiple endocrine neoplasia type 1 (MEN 1). Clinical selection criteria to identify patients who should be tested are needed, as mutation analysis is costly and time consuming. This study is a report of an Australian national mutation testing service for the MEN1 gene from referred patients with classical MEN 1 and various MEN 1-like conditions. RESULTS: All 55 MEN1 mutation positive patients had a family history of hyperparathyroidism, had hyperparathyroidism with one other MEN1 related tumour, or had hyperparathyroidism with multiglandular hyperplasia at a young age. We found 42 separate mutations and six recurring mutations from unrelated families, and evidence for a founder effect in five families with the same mutation. DISCUSSION: Our results indicate that mutations in genes other than MEN1 may cause familial isolated hyperparathyroidism and familial isolated pituitary tumours. CONCLUSIONS: We therefore suggest that routine germline MEN1 mutation testing of all cases of "classical" MEN1, familial hyperparathyroidism, and sporadic hyperparathyroidism with one other MEN1 related condition is justified by national testing services. We do not recommend routine sequencing of the promoter region between nucleotides 1234 and 1758 (Genbank accession no. U93237) as we could not detect any sequence variations within this region in any familial or sporadic cases of MEN1 related conditions lacking a MEN1 mutation. We also suggest that testing be considered for patients <30 years old with sporadic hyperparathyroidism and multigland hyperplasia.

Separate and interacting effects within the catechol-O-methyltransferase (COMT) are associated with schizophrenia.

Several lines of evidence have implicated the catechol-O-methyltransferase (COMT) gene as a candidate for schizophrenia (SZ) susceptibility, not only because it encodes a key dopamine catabolic enzyme but also because it maps to the velocardiofacial syndrome region of chromosome 22q11 which has long been associated with SZ predisposition. The interest in COMT as a candidate SZ risk factor has led to numerous case-control and family-based studies, with the majority placing emphasis on examining a functional Val/Met polymorphism within this enzyme. Unfortunately, these studies have continually produced conflicting results. To assess the genetic contribution of other COMT variants to SZ susceptibility, we investigated three single-nucleotide polymorphisms (SNPs) (rs737865, rs4633, rs165599) in addition to the Val/Met variant (rs4680) in a highly selected sample of Australian Caucasian families containing 107 patients with SZ. The Val/Met and rs4633 variants showed nominally significant associations with SZ (P<0.05), although neither of the individual SNPs remained significant after adjusting for multiple testing (most significant P=0.1174). However, haplotype analyses showed strong evidence of an association; the most significant being the three-marker haplotype rs737865-rs4680-rs165599 (global P=0.0022), which spans more than 26 kb. Importantly, conditional analyses indicated the presence of two separate and interacting effects within this haplotype, irrespective of gender. In addition, our results indicate the Val/Met polymorphism is not disease-causing and is simply in strong linkage disequilibrium with a causative effect, which interacts with another as yet unidentified variant approximately 20 kb away. These results may help explain the inconsistent results reported on the Val/Met polymorphism and have important implications for future investigations into the role of COMT in SZ susceptibility.