Summary Background Observational studies report reduced colorectal cancer in regular aspirin consumers. Randomised controlled trials have shown reduced risk of adenomas but none have employed ...prevention of colorectal cancer as a primary endpoint. The CAPP2 trial aimed to investigate the antineoplastic effects of aspirin and a resistant starch in carriers of Lynch syndrome, the major form of hereditary colorectal cancer; we now report long-term follow-up of participants randomly assigned to aspirin or placebo. Methods In the CAPP2 randomised trial, carriers of Lynch syndrome were randomly assigned in a two-by-two factorial design to 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo, for up to 4 years. Randomisation was in blocks of 16 with provision for optional single-agent randomisation and extended postintervention double-blind follow-up; participants and investigators were masked to treatment allocation. The primary endpoint was development of colorectal cancer. Analysis was by intention to treat and per protocol. This trial is registered, ISRCTN59521990. Results 861 participants were randomly assigned to aspirin or aspirin placebo. At a mean follow-up of 55·7 months, 48 participants had developed 53 primary colorectal cancers (18 of 427 randomly assigned to aspirin, 30 of 434 to aspirin placebo). Intention-to-treat analysis of time to first colorectal cancer showed a hazard ratio (HR) of 0·63 (95% CI 0·35–1·13, p=0·12). Poisson regression taking account of multiple primary events gave an incidence rate ratio (IRR) of 0·56 (95% CI 0·32–0·99, p=0·05). For participants completing 2 years of intervention (258 aspirin, 250 aspirin placebo), per-protocol analysis yielded an HR of 0·41 (0·19–0·86, p=0·02) and an IRR of 0·37 (0·18–0·78, p=0·008). No data for adverse events were available postintervention; during the intervention, adverse events did not differ between aspirin and placebo groups. Interpretation 600 mg aspirin per day for a mean of 25 months substantially reduced cancer incidence after 55·7 months in carriers of hereditary colorectal cancer. Further studies are needed to establish the optimum dose and duration of aspirin treatment. Funding European Union; Cancer Research UK; Bayer Corporation; National Starch and Chemical Co; UK Medical Research Council; Newcastle Hospitals trustees; Cancer Council of Victoria Australia; THRIPP South Africa; The Finnish Cancer Foundation; SIAK Switzerland; Bayer Pharma.
We report an allelic series of eight mutations in GATA2 underlying Emberger syndrome, an autosomal dominant primary lymphedema associated with a predisposition to acute myeloid leukemia. GATA2 is a ...transcription factor that plays an essential role in gene regulation during vascular development and hematopoietic differentiation. Our findings indicate that haploinsufficiency of GATA2 underlies primary lymphedema and predisposes to acute myeloid leukemia in this syndrome.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In the general population, increased adiposity is a significant risk factor for colorectal cancer (CRC), but whether obesity has similar effects in those with hereditary CRC is uncertain. This ...prospective study investigated the association between body mass index and cancer risk in patients with Lynch syndrome (LS).
Participants with LS were recruited to the CAPP2 study, in which they were randomly assigned to receive aspirin 600 mg per day or aspirin placebo, plus resistant starch 30 g per day or starch placebo (2 × 2 factorial design). Mean intervention period was 25.0 months, and mean follow-up was 55.7 months.
During follow-up, 55 of 937 participants developed CRC. For obese participants, CRC risk was 2.41× (95% CI, 1.22 to 4.85) greater than for underweight and normal-weight participants (reference group), and CRC risk increased by 7% for each 1-kg/m(2) increase in body mass index. The risk of all LS-related cancers in obese people was 1.77× (95% CI, 1.06 to 2.96; P = .03) greater than for the reference group. In subgroup analysis, obesity was associated with 3.72× (95% CI, 1.41 to 9.81) greater CRC risk in patients with LS with MLH1 mutation, but no excess risk was observed in those with MSH2 or MSH6 mutation (P = .5). The obesity-related excess CRC risk was confined to those randomly assigned to the aspirin placebo group (adjusted hazard ratio, 2.75; 95% CI, 1.12 to 6.79; P = .03).
Obesity is associated with substantially increased CRC risk in patients with LS, but this risk is abrogated in those taking aspirin. Such patients are likely to benefit from obesity prevention and/or regular aspirin.
Context: The identification of mutations in genes encoding peptides of succinate dehydrogenase (SDH) in pheochromocytoma/paraganglioma syndromes has necessitated clear elucidation of ...genotype-phenotype associations.
Objective: Our objective was to determine genotype-phenotype associations in a cohort of patients with pheochromocytoma/paraganglioma syndromes and succinate dehydrogenase subunit B (SDHB) or subunit D (SDHD) mutations.
Design, Setting, and Participants: The International SDH Consortium studied 116 individuals (83 affected and 33 clinically unaffected) from 62 families with pheochromocytoma/paraganglioma syndromes and SDHB or SDHD mutations. Clinical data were collected between August 2003 and September 2004 from tertiary referral centers in Australia, France, New Zealand, Germany, United States, Canada, and Scotland.
Main Outcome Measures: Data were collected on patients with pheochromocytomas and/or paragangliomas with respect to onset of disease, diagnosis, genetic testing, surgery, pathology, and disease progression. Clinical features were evaluated for evidence of genotype-phenotype associations, and penetrance was determined.
Results: SDHB mutation carriers were more likely than SDHD mutation carriers to develop extraadrenal pheochromocytomas and malignant disease, whereas SDHD mutation carriers had a greater propensity to develop head and neck paragangliomas and multiple tumors. For the index cases, there was no difference between 43 SDHB and 19 SDHD mutation carriers in the time to first diagnosis (34 vs. 28 yr, respectively; P = 0.3). However, when all mutation carriers were included (n = 112), the estimated age-related penetrance was different for SDHB vs. SDHD mutation carriers (P = 0.008).
Conclusions: For clinical follow-up, features of SDHB mutation-associated disease include a later age of onset, extraadrenal (abdominal or thoracic) tumors, and a higher rate of malignancy. In contrast, SDHD mutation carriers, in addition to head and neck paragangliomas, should be observed for multifocal tumors, infrequent malignancy, and the possibility of extraadrenal pheochromocytoma.
Mutations in SCN5A, which encodes the cardiac sodium channel NaV1.5, typically cause ventricular arrhythmia or conduction slowing. Recently, SCN5A mutations have been associated with heart failure ...combined with variable atrial and ventricular arrhythmia.
The purpose of this study was to determine the clinical, genetic, and functional features of an amiodarone-responsive multifocal ventricular ectopy-related cardiomyopathy associated with a novel mutation in a NaV1.5 voltage sensor domain.
A novel, de novo SCN5A mutation (NaV1.5-R225P) was identified in a boy with prenatal arrhythmia and impaired cardiac contractility followed by postnatal multifocal ventricular ectopy suppressible by amiodarone. We investigated the functional consequences of NaV1.5-R225P expressed heterologously in tsA201 cells.
Mutant channels exhibited significant abnormalities in both activation and inactivation leading to large, hyperpolarized window and ramp currents that predict aberrant sodium influx at potentials near the cardiomyocyte resting membrane potential. Mutant channels also exhibited significantly increased persistent (late) sodium current. This profile of channel dysfunction shares features with other SCN5A voltage sensor mutations associated with cardiomyopathy and overlapped that of congenital long QT syndrome. Amiodarone stabilized fast inactivation, suppressed persistent sodium current, and caused frequency-dependent inhibition of channel availability.
We determined the functional consequences and pharmacologic responses of a novel SCN5A mutation associated with an arrhythmia-associated cardiomyopathy. Comparisons with other cardiomyopathy-associated NaV1.5 voltage sensor mutations revealed a pattern of abnormal voltage dependence of activation as a shared biophysical mechanism of the syndrome.
Summary Background Observational studies report that higher intake of dietary fibre (a heterogeneous mix including non-starch polysaccharides and resistant starches) is associated with reduced risk ...of colorectal cancer, but no randomised trials with prevention of colorectal cancer as a primary endpoint have been done. We assessed the effect of resistant starch on the incidence of colorectal cancer. Methods In the CAPP2 study, individuals with Lynch syndrome were randomly assigned in a two-by-two factorial design to receive 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo, for up to 4 years. Randomisation was done with a block size of 16. Post-intervention, patients entered into double-blind follow-up; participants and investigators were masked to treatment allocation. The primary endpoint for this analysis was development of colorectal cancer in participants randomly assigned to resistant starch or resistant-starch placebo with both intention-to-treat and per-protocol analyses. This study is registered, ISRCTN 59521990. Findings 463 patients were randomly assigned to receive resistant starch and 455 to receive resistant-starch placebo. At a median follow-up 52·7 months (IQR 28·9–78·4), 53 participants developed 61 primary colorectal cancers (27 of 463 participants randomly assigned to resistant starch, 26 of 455 participants assigned to resistant-starch placebo). Intention-to-treat analysis of time to first colorectal cancer showed a hazard ratio (HR) of 1·40 (95% CI 0·78–2·56; p=0·26) and Poisson regression accounting for multiple primary events gave an incidence rate ratio (IRR) of 1·15 (95% CI 0·66–2·00; p=0·61). For those completing 2 years of intervention, per-protocol analysis yielded a HR of 1·09 (0·55–2·19, p=0·80) and an IRR of 0·98 (0·51–1·88, p=0·95). No information on adverse events was gathered during post-intervention follow-up. Interpretation Resistant starch had no detectable effect on cancer development in carriers of hereditary colorectal cancer. Dietary supplementation with resistant starch does not emulate the apparently protective effect of diets rich in dietary fibre against colorectal cancer. Funding European Union, Cancer Research UK, Bayer Corporation, National Starch and Chemical Co, UK Medical Research Council, Newcastle Hospitals Trustees, Cancer Council of Victoria Australia, THRIPP South Africa, The Finnish Cancer Foundation, SIAK Switzerland, and Bayer Pharma.
Context:
Pheochromocytoma/paraganglioma occurs almost exclusively after paternal transmission of succinate dehydrogenase D (SDHD) mutations. This parent-of-origin effect has not been fully explained ...but is accompanied by obligate loss of the maternal copy of chromosome 11. Loss of wild-type SDHD and an additional imprinted gene (hypothesized to be H19) appears necessary for tumor formation. Two previous reports suggested tumor formation after maternal transmission of SDHD mutation, but histological and molecular characterization was unavailable.
Objective:
We report the first kindred in which histologically confirmed pheochromocytoma/ paraganglioma occurred after maternal transmission of an SDHD mutation and investigate the molecular mechanism of tumor formation.
Design:
The design of the investigation was the study of a three-generation family with SDHD c.242C>T (p.Pro81Leu) mutation.
Results:
The index patient had a histologically confirmed pheochromocytoma and an identical SDHD germline mutation (p.Pro81Leu) to her mother (who had a glomus jugulare tumor) and paraganglioma tissue from her maternal grandfather. Tumor DNA from the index patient revealed loss of heterozygosity (LOH) at 11q23, causing loss of the wild-type paternal SDHD allele and LOH affecting maternal 11p15, including H19. These two regions of LOH were separated by a region exhibiting clearly retained heterozygosity, including SDHAF2, a recently reported paraganglioma susceptibility gene.
Conclusions:
Tumor formation can occur after maternal transmission of SDHD, a finding with important clinical implications for SDHD families. Tumor formation in SDHD mutation requires the loss of both the wild-type SDHD allele and maternal 11p15, leading to the predominant but now not exclusive pattern of disease inheritance after paternal SDHD transmission.
The autosomal recessive form of Robinow syndrome (RRS; MIM 268310) is a severe skeletal dysplasia with generalized limb bone shortening, segmental defects of the spine, brachydactyly and a dysmorphic ...facial appearance. We previously mapped the gene mutated in RRS to chromosome 9q22 (ref. 4), a region that overlaps the locus for autosomal dominant brachydactyly type B (refs 5,6). The recent identification of ROR2, encoding an orphan receptor tyrosine kinase, as the gene mutated in brachydactyly type B (BDB1; ref. 7) and the mesomelic dwarfing in mice homozygous for a lacZ and/or a neo insertion into Ror2 (refs 8,9) made this gene a candidate for RRS. Here we report homozygous missense mutations in both intracellular and extracellular domains of ROR2 in affected individuals from 3 unrelated consanguineous families, and a nonsense mutation that removes the tyrosine kinase domain and all subsequent 3′ regions of the gene in 14 patients from 7 families from Oman. The nature of these mutations suggests that RRS is caused by loss of ROR2 activity. The identification of mutations in three distinct domains (containing Frizzled-like, kringle and tyrosine kinase motifs) indicates that these are all essential for ROR2 function.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Nance-Horan syndrome (NHS) is an X-linked developmental disorder characterized by congenital cataract, dental anomalies, facial dysmorphism and, in some cases, mental retardation. Protein truncation ...mutations in a novel gene (NHS) have been identified in patients with this syndrome. We previously mapped X-linked congenital cataract (CXN) in one family to an interval on chromosome Xp22.13 which encompasses the NHS locus; however, no mutations were identified in the NHS gene. In this study, we show that NHS and X-linked cataract are allelic diseases. Two CXN families, which were negative for mutations in the NHS gene, were further analysed using array comparative genomic hybridization. CXN was found to be caused by novel copy number variations: a complex duplication–triplication re-arrangement and an intragenic deletion, predicted to result in altered transcriptional regulation of the NHS gene. Furthermore, we also describe the clinical and molecular analysis of seven families diagnosed with NHS, identifying four novel protein truncation mutations and a novel large deletion encompassing the majority of the NHS gene, all leading to no functional protein. We therefore show that different mechanisms, aberrant transcription of the NHS gene or no functional NHS protein, lead to different diseases. Our data highlight the importance of copy number variation and non-recurrent re-arrangements leading to different severity of disease and describe the potential mechanisms involved.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heart muscle disease of unknown etiology that causes arrhythmias, heart failure, and sudden death. Diagnosis can be difficult, and this ...hampers investigation of its molecular basis. Forms of ARVC in which gene penetrance and disease expression are greater should facilitate genetic study. We undertook a clinical and genetic investigation of Naxos disease, originally described by Protonotarios in 1986. This disease constitutes the triad of ARVC, diffuse nonepidermolytic palmoplantar keratoderma, and woolly hair.
We evaluated the population of Naxos, Greece, to identify probands, which was followed by family screening. Twenty-one affected persons from 9 families of 150 persons were identified. Linkage analysis was performed with microsatellite markers. The disease locus mapped to 17q21. A peak 2-point LOD score of 3.62 at theta=0.0 was found with a marker within intron 4 of the keratin 9 gene, a member of the type I (acidic) keratin family. A preserved homozygous disease haplotype was identified. Haplotype analysis delimited the disease interval.
Hair and skin abnormalities were found to be reliable markers of subsequent heart disease. This suggests the presence of a single mutant gene with novel cardiac, skin, and hair function or two or more tightly linked disease genes. Recessive inheritance of Naxos disease and a founder effect were demonstrated. Identification of a fully informative genetic marker linked to the disease and uncommon in the background population may be of use as a test to identify disease gene carriers.
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