Retinal hemangioblastoma: prevalence, incidence and frequency of underlying von Hippel-Lindau disease.

BACKGROUND AND AIMS: We aimed to determine the frequency of von Hippel-Lindau disease (vHL) as the underlying cause of retinal hemangioblastoma and to estimate retinal hemangioblastoma incidence and prevalence in a national cohort study. METHODS: Through the national patient register and vHL research database, we identified 81 patients diagnosed with a retinal hemangioblastoma in Denmark between 1977 and 2014. Consent was obtained for 54 living and 10 deceased patients with retinal hemangioblastoma. For each participant, we collected medical records and family information. Almost all (63 of 64) participants were or had previously been tested for mutations in the VHL gene. RESULTS: Overall, 84% of the participants (54 of the 64) had vHL. Compared with the non-vHL patients, the vHL patients had their first retinal hemangioblastoma at a younger age (22.5 vs 40 years), and were more likely to have an asymptomatic first hemangioblastoma (80% vs 20%). Overall, 76% (41 of 54) of the vHL patients had a family history of vHL, while none of the patients without vHL did. Despite the rarity of the disease, on average more than eight new tumours are diagnosed each year due to multiple tumour development in vHL patients. The estimated prevalence of patients with retinal hemangioblastoma was up to 1 in 73 080 individuals. CONCLUSION: In the first national study in which almost all participants were genetically tested, vHL was the underlying cause of retinal hemangioblastoma in 84% of cases; more often than previously reported. We recommend that genetic and clinical vHL screening should be performed in all patients with retinal hemangioblastoma.

Familial Colorectal Cancer Type X.

The genetic background is unknown for the 50-60% of the HNPCC families, who fulfill the Amsterdam criteria, but do not have a mutation in an MMR gene, and is referred to as FCCTX. This study reviews the clinical, morphological and molecular characteristics of FCCTX, and discusses the molecular genetic methods used to localize new FCCTX genes, along with an overview of the genes and chromosomal areas that possibly relate to FCCTX. FCCTX is a heterogeneous group, mainly comprising cases caused by single high-penetrance genes, or by multiple low-penetrance genes acting together, and sporadic CRC cases. FCCTX differs in clinical, morphological and molecular genetic characteristics compared to LS, including a later age of onset, distal location of tumours in the colon, lower risk of developing extracolonic tumours and a higher adenoma/carcinoma ratio, which indicates a slower progression to CRC. Certain characteristics are shared with sporadic CRC, e.g. similarities in gene expression and a high degree of CIN+, with significanly increased 20q gain in FCCTX. Other molecular characteristics of FCCTX include longer telomere length and hypomethylation of LINE-1, both being a possible explanation for CIN+. Some genes in FCCTX families (RPS20, BMPR1A, SEMA4A) have been identified by using a combination of linkage analysis and sequencing. Sequencing strategies and subsequent bioinformatics are improving fast. Exome sequencing and whole genome sequencing are currently the most promising tools. Finally, the involvement of CNV's and regulatory sequences are widely unexplored and would be interesting for further investigation in FCCTX.

von Hippel-Lindau development in children and adolescents.

The autosomal dominant von Hippel-Lindau disease (vHL) is associated with a lifelong risk of tumor development, especially retinal and CNS hemangioblastomas, pheochromocytoma, and renal cell carcinoma. Knowledge of paediatric vHL development is limited, and current surveillance guidelines are based on expert opinions. We aimed to describe the course of vHL development in children and adolescents, focusing on age at first manifestation, manifestation frequencies, and types. The prevalence of vHL diagnosis as well as manifestations in childhood were evaluated based on 99 patients, who had started surveillance before 18 years: 37 Danish patients from the national vHL research database and 62 international patients reported in 15 articles. Overall, 70% (69 of 99) developed manifestations before 18 years (median age at first manifestation: 12 years (range: 6-17 years)). Thirty per cent (30 of 99) had developed more than one manifestation type; the most frequent were retinal (34%) and CNS (30%) hemangioblastomas. Among the 37 Danish patients, 85% (97 of 116) of their tumors were asymptomatic. Vision outcome is significantly improved in hemangioblastomas that are treated while still asymptomatic. We agree with current guidelines that retinal surveillance be performed from birth. The patients had their first CNS hemangioblastomas at the median ages of 13-14 years (range: 6-17 years). Further, 11% (4 of 37) of the Danish patients had CNS surgery in their teenage years. Although the cohort is too small to make definite conclusions about specific initiation ages, regular CNS surveillance from vHL patients' teenage years seems clinically relevant.

Management of Gene Variants of Unknown Significance: Analysis Method and Risk Assessment of the VHL Mutation p.P81S (c.241C>T).

BACKGROUND: Evaluation of the pathogenicity of a gene variant of unknown significance (VUS) is crucial for molecular diagnosis and genetic counseling, but can be challenging. This is especially so in phenotypically variable diseases, such as von Hippel-Lindau disease (vHL). vHL is caused by germline mutations in the VHL gene, which predispose to the development of multiple tumors such as central nervous system hemangioblastomas and renal cell carcinoma (RCC). OBJECTIVE: We propose a method for the evaluation of VUS pathogenicity through our experience with the VHL missense mutation c.241C>T (p.P81S). METHOD: 1) Clinical evaluation of known variant carriers: We evaluated a family of five VHL p.P81S carriers, as well as the clinical characteristics of all the p.P81S carriers reported in the literature; 2) Evaluation of tumor tissue via genetic analysis, histology, and immunohistochemistry (IHC); 3) Assessment of the variant's impact on protein structure and function, using multiple databases, in silico algorithms, and reports of functional studies. RESULTS: Only one family member had clinical signs of vHL with early-onset RCC. IHC analysis showed no VHL protein expressed in the tumor, consistent with biallelic VHL inactivation. The majority of in silico algorithms reported p.P81S as possibly pathogenic in relation to vHL or RCC, but there were discrepancies. Functional studies suggest that p.P81S impairs the VHL protein's function. CONCLUSION: The VHL p.P81S mutation is most likely a low-penetrant pathogenic variant predisposing to RCC development. We suggest the above-mentioned method for VUS evaluation with use of different methods, especially a variety of in silico methods and tumor tissue analysis.

Survival and causes of death in patients with von Hippel-Lindau disease.

BACKGROUND: Historically, the survival of patients with von Hippel-Lindau disease (vHL) has been poorer than that of the general population. We aimed to determine whether the survival of VHL mutation carriers and their risk of vHL-related death has changed over time and how it has been affected by sex, genotype and surveillance attendance. METHODS: In a retrospective cohort study, we included all known Danish vHL families with a VHL mutation. We assessed the survival and causes of death for 143 VHL mutation carriers using Cox regression models and compared vHL survival with that of 137 siblings without vHL. vHL life expectancy was compared with the general population using a relative survival model. RESULTS: The estimated mean life expectancies for male and female patients born in 2000 were 67 and 60 years, respectively. Survival is influenced by the sex and genotype of the patient. Female patients have a significantly higher risk of vHL-related death than male patients (HR=2.25, 95% CI 1.20 to 4.20, p=0.011). Overall, 79% (53 of 67) of deaths were vHL-related, but the risk of vHL-related death has decreased over time, as has the frequency of renal cell carcinoma (RCC)-related death. Surveillance is especially beneficial for truncating mutation carriers, who have the greatest RCC and central nervous system (CNS) hemangioblastoma risk. CONCLUSIONS: vHL survival has improved over time and has become closer to that of siblings without vHL and the general population. Even though the risk of vHL-related death has decreased significantly, the main cause of death is still CNS hemangioblastomas and hence improved treatment options are essential.

Risk of new tumors in von Hippel-Lindau patients depends on age and genotype.

PURPOSE: The von Hippel-Lindau (vHL) phenotype is variable, which complicates genetic counseling and surveillance. We describe how the rate of new tumor development varies through the lifetimes of vHL patients and how it is influenced by age and genotype. METHODS: In a national cohort study, we included 52 VHL mutation carriers who were retrospectively followed for a total of 799 person-years. From birth to current age, 581 manifestations were diagnosed during 2,583 examinations in the study subjects. Manifestation rates were analyzed using Poisson regression and compared in groups of different ages, tumor sites, and genotypes. RESULTS: The rate of new tumor development varied significantly with age and was highest at 30-34 years (0.4 new tumors/year). Tumor location further influenced the rate. The risk of retinal tumors was highest in subjects during the teenage years but was highest for cerebellar tumors in subjects during their 30s. Truncating VHL mutation carriers had a significantly higher manifestation rate compared with missense mutation carriers (hazard ratio = 1.85, 95% confidence interval: 1.06-3.24, P value = 0.031). CONCLUSION: The rate of new manifestation development is not constant throughout the life span of vHL patients; instead, it varies significantly with age and genotype and depends on anatomical location. Retinal surveillance is crucial during the teenage years, whereas cerebellar surveillance is especially important in adulthood.Genet Med 18 1, 89-97.

New von Hippel-Lindau manifestations develop at the same or decreased rates in pregnancy.

OBJECTIVE: In a national retrospective cohort study, we aimed to determine the effect of pregnancy on new von Hippel-Lindau (vHL) tumor development during pregnancy and at 1, 3, and 5 years after conception. METHODS: We included 52 VHL mutation carriers (26 men and 26 women) with 581 manifestations diagnosed throughout their lifetimes. We analyzed age-dependent manifestation rates using Poisson regression. We compared the women's rates in intervals where they had been pregnant with their age-matched nonpregnant intervals. We investigated possible long-term effects using pregnancy intervals of increasing lengths of 1, 3, and 5 years after conception. Furthermore, we compared age-related manifestation rates for women and men. RESULTS: From birth to the participants' current age, 581 manifestations were diagnosed; mean age was 37.5 years (range 2-64 years). Seventeen women had completed 30 pregnancies. Manifestation rates in women's pregnant intervals were lower compared with their age-matched nonpregnant intervals (1 year: hazard ratio [HR] = 0.439, 95% confidence interval [CI] 0.131-1.474, p = 0.18; 3 years: HR = 0.412, 95% CI 0.214-0.796, p = 0.0083; and 5 years: HR = 0.450, 95% CI 0.136-1.489, p = 0.19). Men and women had similar manifestation rates, both increasing from their 20s. CONCLUSIONS: Pregnancy does not aggravate vHL tumor development, and we neither discourage pregnancy in VHL mutation carriers nor recommend intensified surveillance during pregnancy. The pregnancy effect is not due to concurrence of a naturally milder tumor development in women's fertile ages, as the rate of new tumor development increases for both men and women from 20 years of age, even more in men than in women.

Obesity, Aspirin, and Risk of Colorectal Cancer in Carriers of Hereditary Colorectal Cancer: A Prospective Investigation in the CAPP2 Study.

PURPOSE: 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). PATIENTS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

The analysis of a large Danish family supports the presence of a susceptibility locus for adenoma and colorectal cancer on chromosome 11q24.

Hereditary colorectal cancer accounts for approximately 30% of all colorectal cancers, but currently only 5% of these families can be explained by highly penetrant, inherited mutations. In the remaining 25% it is not possible to perform a gene test to identify the family members who would benefit from prophylactic screening. Consequently, all family members are asked to follow a screening program. The purpose of this study was to localize a new gene which causes colorectal cancer. We performed a linkage analysis using data from a SNP6.0 chip in one large family with 12 affected family members. We extended the linkage analysis with microsatellites (STS) and single nucleotide polymorphisms (SNP's) and looked for the loss of heterozygosity in tumour tissue. Furthermore, we performed the exome sequencing of one family member and we sequenced candidate genes by use of direct sequencing. Major rearrangements were excluded after karyotyping. The linkage analysis with SNP6 data revealed three candidate areas, on chromosome 2, 6 and 11 respectively, with a LOD score close to two and no negative LOD scores. After extended linkage analysis, the area on chromosome 6 was excluded, leaving areas on chromosome 2 and chromosome 11 with the highest possible LOD scores of 2.6. Two other studies have identified 11q24 as a candidate area for colorectal cancer susceptibility and this area is supported by our results.

Von Hippel-Lindau disease (vHL). National clinical guideline for diagnosis and surveillance in Denmark. 3rd edition.

These clinical guidelines outline the criteria and recommendations for diagnostic and genetic work-up of families suspected of von Hippel-Lindau disease (vHL), as well as recommendations for prophylactic surveillance for vHL patients. The guideline has been composed by the Danish Coordination Group for vHL which is comprised of Danish doctors and specialists interested in vHL. The recommendations are based on longstanding clinical experience, Danish original research, and extensive review of the international literature. vHL is a hereditary multi-tumour disease caused by germline mutations in the VHL gene. vHL is inherited in an autosomal dominant manner. Predisposed individuals are advised to undergo prophylactic examinations, as they are at lifelong risk of developing multiple cysts and tumours, especially in the cerebellum, the spinal cord, the retina (hemangioblastomas), the kidneys (renal cell carcinoma), the adrenal glands (pheochromocytoma), the pancreas, as well as in other organs. As many different organs can be affected, several medical specialities often take part in both diagnosis and treatment of manifestations. vHL should be suspected in individuals with a family history of the disease, and/or in individuals with a vHL-associated manifestation; i.e. a hemangioblastoma in the retina or the central nervous system, familial or bilateral pheochromocytomas, familial, multiple, or early onset renal cell carcinomas, and in individuals with an endolymphatic sac tumour in the inner ear. Individuals suspected of vHL should be referred to a department of clinical genetics for genetic work-up and counselling as well as have a clinical work-up to identify any undiagnosed vHL-associated manifestations. This guideline describes the elements of the clinical diagnostic work-up, as well as the genetic work-up, counselling, and mutation screening. Individuals who are affected with vHL, individuals at risk of vHL, and VHL-mutation carriers are advised to follow the surveillance program which consists of regular prophylactic examinations relevant to different age groups. The examinations are recommended to start in infancy with annual paediatric examinations and ophthalmoscopy until the age of five years. From five to 14 years, annual plasma-metanephrine and plasma-normetanephrine tests, as well as annual hearing examinations are added. Also, an MRI (Magnetic Resonance Imaging) examination of the CNS and abdomen should be done between the ages of eight and 14 years. After the age of 15 years, individuals should be referred to: a) annual ophthalmoscopy in dilation, b) annual neurological examination, c) every two years: MRIs of the CNS, including the inner ear, d) annual ultrasound/MRI of the abdomen, e) annual plasma-metanephrine, plasma-normetanephrine, and plasma-chromogranin A tests, and f) annual hearing examination at a department of audiology. It is advised that one doctor takes on the responsibility of coordination of and referral to the many examinations, and the communication with the patient. To facilitate the coordination, and especially for the patients' own use, a mobile chart can be used. In 2012, the Danish vHL Coordination Group established a national vHL database comprising individuals with vHL and their relatives, as well as individuals examined for vHL. The database is designated to be a treatment and diagnostic instrument, as well as a tool in future vHL research in Denmark.

von Hippel-Lindau disease: deafness due to a non-MRI-visible endolymphatic sac tumor despite targeted screening.

OBJECTIVE: Endolymphatic sac tumours (ELSTs) of the inner ear occur in 16% of patients with the hereditary tumor syndrome von Hippel-Lindau disease (vHL). ELSTs of all sizes can cause irreversible hearing loss which can, however, be prevented through early diagnosis and treatment. We aim to emphasize the challenges of prophylactic ELST screening and to explore the role of audiometry in pre-symptomatic ELST screening. DESIGN: For a period of 17 years our patient was screened for ELSTs with inner-ear MRI (magnetic resonance imaging), audiometry, and clinical interviews. STUDY SAMPLE: A male vHL patient who became deaf in one ear due to a radiologically undetectable ELST. RESULTS: Despite annual MRIs, the ELST was not visible until four months after onset of deafness when it appeared as a 1.4 × 1.4 mm tumor mass. Although his hearing was objectively within normal limits for the first 14 years, a distinct pattern of low-frequency hearing loss could retrospectively be seen at all audiometries. CONCLUSIONS: Audiometry is a candidate screening tool for detection of non-symptomatic pre-MRI-visible ELSTs, and we have initiated an international collaborative study to further determine its application. At present, we suggest an ELST screening protocol of yearly audiological assessment and inner ear MRI.

Long-term effect of resistant starch on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial.

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.

Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial.

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.

von Hippel-Lindau disease: surveillance strategy for endolymphatic sac tumors.

PURPOSE: : Up to 16% of patients with the hereditary von Hippel-Lindau disease develop endolymphatic sac tumors of the inner ear. Early diagnosis and treatment of endolymphatic sac tumors can prevent audiovestibular morbidity, but optimal endolymphatic sac tumor surveillance strategy has yet to be determined. We aimed to evaluate endolymphatic sac tumor surveillance to determine the best surveillance strategy. METHODS: : In a national prospective study, 40 VHL mutation carriers were interviewed about audiovestibular symptoms and had audiological examinations and magnetic resonance imaging of the inner ear. Further, we performed a meta-analysis including all reported endolymphatic sac tumor von Hippel-Lindau disease cases in the literature (N = 140 with 156 endolymphatic sac tumors). RESULTS: : In the prospective study, endolymphatic sac tumors were suspected based on audiovestibular symptoms, audiometry, and magnetic resonance imaging in 34%, 30%, and 12.5% of subjects, respectively. In total, more than 90% of radiologically diagnosed endolymphatic sac tumors were associated with abnormal audiometric findings. No endolymphatic sac tumor genotype-phenotype correlations were found. CONCLUSION: : We recommend annual audiometry as a first-line endolymphatic sac tumor screening tool, and in countries where periodic surveillance magnetic resonance imaging of the central nervous system is performed, specific images of the inner ear should be included. Audiometric abnormalities in patients with von Hippel-Lindau disease without magnetic resonance imaging-visible endolymphatic sac tumors could be due to microscopic endolymphatic sac tumors. Determination of audiometric endolymphatic sac tumor characteristics could further target screening and improve endolymphatic sac tumor diagnosis.

Mosaicism in segmental Darier disease: an in-depth molecular analysis quantifying proportions of mutated alleles in various tissues.

Darier disease is an autosomal dominant genodermatosis caused by germline mutations in the ATP2A2 gene. Clinical expression is variable, including rare segmental phenotypes thought to be caused by postzygotic mosaicism. Genetic counseling of segmental Darier patients is complex, as risk of transmitting a nonsegmental phenotype to offspring is of unknown magnitude. We present the first in-depth molecular analysis of a mosaic patient with segmental disease, quantifying proportions of mutated and normal alleles in various tissues. Pyrosequence analysis of DNA from semen, affected and normal skin, peripheral leukocytes and hair revealed an uneven distribution of the mutated allele, from 14% in semen to 37% in affected skin. We suggest a model for segmental manifestation expression where a threshold number of mutated cells is needed for manifestation development. We further recommend molecular analysis of the ATP2A2 gene in semen of male patients with segmental Darier disease to improve genetic counseling.

A BRCA2 mutation incorrectly mapped in the original BRCA2 reference sequence, is a common West Danish founder mutation disrupting mRNA splicing.

Inherited mutations in the tumor suppressor genes BRCA1 and BRCA2 predispose carriers to breast and ovarian cancer. The authors have identified a mutation in BRCA2, 7845+1G>A (c.7617+1G>A), not previously regarded as deleterious because of incorrect mapping of the splice junction in the originally published genomic reference sequence. This reference sequence is generally used in many laboratories and it maps the mutation 16 base pairs inside intron 15. However, according to the recent reference sequences the mutation is located in the consensus donor splice sequence. By reverse transcriptase analysis, loss of exon 15 in the final transcript interrupting the open reading frame was demonstrated. Furthermore, the mutation segregates with a cancer phenotype in 18 Danish families. By genetic analysis of more than 3,500 Danish breast/ovarian cancer risk families, the mutation was identified as the most common BRCA2 mutation in West Denmark, while it is rare in Central and East Denmark and not identified in South Sweden. Haplotype analysis using dense SNP arrays indicated a common founder of the mutation approximately 1,500 years ago.

Familial colorectal cancer, can it be identified by microsatellite instability and chromosomal instability? - A case-control study.

Colonoscopy is recommended for persons with a familial risk of colorectal cancer (CRC). A familial risk is identified by a family history with CRC and/or predisposing mutation(s). However, such information may not be available. We analysed whether MSI (MicroSatellite Instability) and/or CIN (Chromosome INstability=LOH (loss of heterozygosity) and/or DNA-aneuploidy (abnormal nuclear DNA contents)) could be used as predictors of familial CRC. Formalin-fixed tissue from 97 patients with CRC (29 patients with 2 or more affected first-degree relatives (="cases"), 29 matched CRC controls without a family history, and 39 relatives to cases) were analysed for MSI and CIN. In this small case-control study, no significant differences in the frequencies of MSI and CIN were observed between cases with a family history and their controls without a family history. MSI+;CIN- was observed in 6/29 cases and in 0/29 controls (p=0.02), most frequently in cases with affected siblings, only (3/7). However, for 13 patients from whom several CRC tumours were analysed, concordant results for MSI/LOH/DNA-ploidy were obtained only in 10/9/9. Among cases and relative(s), concordant results for MSI, LOH and DNA-ploidy were obtained in 16/26, 16/26, and 14/25 families, respectively.Although MSI+;CIN- appeared to predict familial CRC with a high specificity, neither MSI, CIN, or MSI+;CIN- are likely to be sufficiently sensitive predictors of familial CRC.

Genotype predicting phenotype in familial adenomatous polyposis: a practical application to the choice of surgery.

PURPOSE: Genetic information may help preoperatively select patients with familial adenomatous polyposis for either colectomy with ileorectal anastomosis or proctocolectomy with ileal pouch-anal anastomosis. Although complicated, the latter procedure has a low long-term risk of rectal cancer. METHODS: Data were obtained from four national polyposis registries. On the basis of previously described genotype-phenotype correlations, patients were divided into three genotype groups predicting attenuated, intermediate, and severe polyposis phenotypes. Cumulative risks of secondary proctectomy and rectal cancer after primary colectomy were calculated using the Kaplan-Meier method. RESULTS: Four hundred and seventy-five polyposis patients with a previous colectomy were included. Cumulative risks of secondary proctectomy 20 years after primary colectomy were 10%, 39%, and 61% in the attenuated, intermediate, and severe genotype groups, respectively (P < 0.05, groups compared separately). Cumulative risks of rectal cancer after primary colectomy were 3.7%, 9.3%, and 8.3%, respectively, in the three groups (P > 0.05, groups compared separately). CONCLUSION: Mutation analysis may be used to predict the risk of secondary proctectomy after primary colectomy in familial adenomatous polyposis. Patients with severe genotypes have a high risk of reoperation after primary colectomy and will benefit from primary proctocolectomy with ileal pouch-anal anastomosis. The risk of rectal cancer after primary colectomy was not significantly different between the three groups.

A high frequent BRCA1 founder mutation identified in the Greenlandic population.

Approximately 10% of all breast and ovarian cancers are dominantly inherited and mutations are mainly found in the BRCA 1 and 2 genes. The penetrance of BRCA1 mutations is reported to be between 68 and 92% and confers a 36-92% life time risk of breast cancer. Most mutations in BRCA1 are uniquely occurring mutations, but founder mutations have been described. In this study we describe a founder mutation with wide spread presence in the Inuit population. We have screened 2,869 persons from Greenland for the presence of a BRCA1 mutation (p.Cys39Gly) only found in the Inuit population. The overall carrier frequency was 1.6% in the general population, but the frequency differs geographically from 0.6% on the West coast to 9.7% in the previously isolated population of the East coast. This is to our knowledge the highest population frequency of a BRCA1 mutation ever to be described. To determine the clinical relevance of the mutation, we have examined ten breast cancer patients and nine ovarian cancer patients from Greenland for the presence of the p.Cys39Gly mutation. We found three ovarian cancer patients (33%) and one breast cancer patient (10%) carrying the mutation. The high number of women carrying a BRCA1 mutation known to trigger the development of potentially lethal diseases leads us to recommend an offer of genetic counselling and test for the mutation to all females of Inuit origin, thereby hopefully preventing a number of breast and ovarian cancer deaths.

Effect of aspirin or resistant starch on colorectal neoplasia in the Lynch syndrome.

BACKGROUND: Observational and epidemiologic data indicate that the use of aspirin reduces the risk of colorectal neoplasia; however, the effects of aspirin in the Lynch syndrome (hereditary nonpolyposis colon cancer) are not known. Resistant starch has been associated with an antineoplastic effect on the colon. METHODS: In a randomized, placebo-controlled trial, we used a two-by-two design to investigate the effects of aspirin, at a dose of 600 mg per day, and resistant starch (Novelose), at a dose of 30 g per day, in reducing the risk of adenoma and carcinoma among persons with the Lynch syndrome. RESULTS: Among 1071 persons in 43 centers, 62 were ineligible to participate in the study, 72 did not enter the study, and 191 withdrew from the study. These three categories were equally distributed across the study groups. Over a mean period of 29 months (range, 7 to 74), colonic adenoma or carcinoma developed in 141 participants. Of 693 participants randomly assigned to receive aspirin or placebo, neoplasia developed in 66 participants receiving aspirin (18.9%), as compared with 65 receiving placebo (19.0%) (relative risk, 1.0; 95% confidence interval [CI], 0.7 to 1.4). There were no significant differences between the two groups with respect to the development of advanced neoplasia (7.4% and 9.9%, respectively; P=0.33). Among the 727 participants receiving resistant starch or placebo, neoplasia developed in 67 participants receiving starch (18.7%), as compared with 68 receiving placebo (18.4%) (relative risk, 1.0; 95% CI, 0.7 to 1.4). Advanced adenomas and colorectal cancers were evenly distributed in the two groups. The prevalence of serious adverse events was low, and the events were evenly distributed. CONCLUSIONS: The use of aspirin, resistant starch, or both for up to 4 years has no effect on the incidence of colorectal adenoma or carcinoma among carriers of the Lynch syndrome. (Current Controlled Trials number, ISRCTN59521990.)