A wide range of factor VIII and IX levels is observed in heterozygous carriers of hemophilia as well as in noncarriers. In female carriers, extreme lyonization may lead to low clotting factor levels. ...We studied the effect of heterozygous hemophilia carriership on the occurrence of bleeding symptoms. A postal survey was performed among most of the women who were tested for carriership of hemophilia in the Netherlands before 2001. The questionnaire included items on personal characteristics, characteristics of hemophilia in the affected family members, and carrier testing and history of bleeding problems such as bleeding after tooth extraction, bleeding after tonsillectomy, and other operations. Information on clotting factor levels was obtained from the hospital charts. Logistic regression was used to assess the relation of carrier status and clotting factor levels with the occurrence of hemorrhagic events. In 2004, 766 questionnaires were sent, and 546 women responded (80%). Of these, 274 were carriers of hemophilia A or B. The median clotting factor level of carriers was 0.60 IU/mL (range, 0.05-2.19 IU/mL) compared with 1.02 IU/mL (range, 0.45-3.28 IU/mL) in noncarriers. Clotting factor levels from 0.60 to 0.05 IU/mL were increasingly associated with prolonged bleeding from small wounds and prolonged bleeding after tooth extraction, tonsillectomy, and operations. Carriers of hemophilia bleed more than other women, especially after medical interventions. Our findings suggest that not only clotting factor levels at the extreme of the distribution, resembling mild hemophilia, but also mildly reduced clotting factor levels between 0.41 and 0.60 IU/mL are associated with bleeding. (Blood. 2006;108:52-56)
The patient with a family history for colorectal carcinoma constitutes a complicated diagnostic challenge involving many clinicians. The diagnostic workup of familial colorectal cancer is an ...elaborate and time consuming process in which the family and several medical specialists closely collaborate. However, establishing a diagnosis can be very rewarding. If a mutation is detected in the family, a satisfactory explanation can be provided for an accumulation of tumors at young age, and often of untimely death. Appropriate presymptomatic testing can be offered to reduce mortality among at‐risk family members, and relatives not at risk can avoid uncertainty and needlessly intensive surveillance.
We show the differential diagnostic considerations when an individual with a family history of colorectal carcinoma is encountered, with emphasis on Lynch syndrome (Hereditary Nonpolyposis Colorectal Carcinoma HNPCC). Practical recommendations for laboratory workup of suspected Lynch syndrome, including analysis of tumor tissue by microsatellite instability analysis and immunohistochemistry, and germline DNA analysis are given. Furthermore, the clinical management after a molecular diagnosis has been made is described. The diagnostic scheme presented here allows efficient and effective analysis of colorectal carcinoma cases with (suspected) Lynch syndrome, making optimal use of currently available technology.
Immunohistochemistry (IHC) and microsatellite instability (MSI) analysis can be used to identify patients with a possible DNA mismatch repair defect hereditary nonpolyposis colorectal carcinoma ...(HNPCC). The Bethesda criteria have been proposed to select families for determination of MSI. The aims of this study were to assess the yield of MSI analysis in families suspected for HNPCC, to compare the results of immunohistochemical staining and MSI analysis, and to assess the additional value of PMS2 staining.
Clinical data and tumors were collected from 725 individuals from 631 families with suspected HNPCC. MSI analysis was performed using eight markers including the 5 National Cancer Institute markers. Four immunohistochemical staining antibodies were used (MLH1, MSH2, MSH6 and PMS2).
A MSI-H (tumors with instability for >30% of the markers) phenotype in colorectal cancers (CRCs) was observed in 21-49% of families that met the various Bethesda criteria. In families with three cases of CRC diagnosed at age > 50 years, families with a solitary case of CRC diagnosed between ages 45 and 50 years, and families with one CRC case and a first-degree relative with a HNPCC-related cancer, one diagnosed between ages 45 and 50 years (all Bethesda-negative families), the yield of MSI-H was 10-26%. Immunohistochemical staining confirmed the MSI results in 93% of the cases. With IHC, adding PMS2 staining led to the identification of an additional 23% of subjects with an hMLH1 germ-line mutation (35 carriers were tested).
The Bethesda guidelines for MSI analysis should include families with three or more cases of CRC diagnosed at age > 50 years. The age at diagnosis of CRC in the original guidelines should be raised to 50 years. Routine IHC diagnostics for HNPCC should include PMS2 staining.
Li-Fraumeni syndrome (LFS) is a hereditary cancer syndrome, characterized by a high risk of developing cancer at various sites and ages. To date, limited clinical benefits of genetic testing for LFS ...have been demonstrated, and there are concerns about the potential adverse psychosocial impact of genetic testing for LFS. In this study, we evaluated the uptake of genetic testing and the psychosocial impact of undergoing or not undergoing a genetic test for LFS.
In total, 18 families with a p53 germline mutation in the Netherlands were identified. Eligible family members were invited to complete a self-report questionnaire assessing motives for undergoing or not undergoing genetic testing, LFS-related distress and worries, and health-related quality of life.
Uptake of presymptomatic testing was 55% (65 of 119). Of the total group, 23% reported clinically relevant levels of LFS-related distress. Carriers were not significantly more distressed than noncarriers or than those with a 50% risk who did not undergo genetic testing. Those with a lack of social support were more prone to report clinically relevant levels of distress (odds ratio, 1.3; 95% CI, 1.0 to 1.5).
Although preventive and treatment options for LFS are limited, more than half of the family members from known LFS families choose to undergo presymptomatic testing. An unfavorable genetic test result, in general, does not cause adverse psychological effects. Nonetheless, it is important to note that a substantial proportion of individuals, irrespective of their carrier status, exhibit clinically relevant levels of distress which warrant psychological support.
Summary Background Paragangliomas and phaeochromocytomas are neuroendocrine tumours associated frequently with germline mutations of SDHD, SDHC , and SDHB . Previous studies have shown the imprinted ...SDHAF2 gene to be mutated in a large Dutch kindred with paragangliomas. We aimed to identify SDHAF2 mutation carriers, assess the clinical genetic significance of SDHAF2 , and describe the associated clinical phenotype. Methods We undertook a multicentre study in Spain and the Netherlands in 443 apparently sporadic patients with paragangliomas and phaeochromocytomas who did not have mutations in SDHD, SDHC , or SDHB . We analysed DNA of 315 patients for germline mutations of SDHAF2 ; a subset (n=200) was investigated for gross gene deletions. DNA from a group of 128 tumours was studied for somatic mutations. We also examined a Spanish family with head and neck paragangliomas with a young age of onset for the presence of SDHAF2 mutations, undertook haplotype analysis in this kindred, and assessed their clinical phenotype. Findings We did not identify any germline or somatic mutations of SDHAF2 , and no gross gene deletions were noted in the subset of apparently sporadic patients analysed. Investigation of the Spanish family identified a pathogenic germline DNA mutation of SDHAF2 , 232G→A (Gly78Arg), identical to the Dutch kindred. Interpretation SDHAF2 mutations do not have an important role in phaeochromocytoma and are rare in head and neck paraganglioma. Identification of a second family with the Gly78Arg mutation suggests that this is a crucial residue for the function of SDHAF2. We conclude that SDHAF2 mutation analysis is justified in very young patients with isolated head and neck paraganglioma without mutations in SDHD, SDHC , or SDHB , and in individuals with familial antecedents who are negative for mutations in all other risk genes. Funding Dutch Cancer Society, European Union 6th Framework Program, Fondo Investigaciones Sanitarias, Fundación Mutua Madrileña, and Red Temática de Investigación Cooperativa en Cáncer.
Background & Aims:
Hereditary nonpolyposis colorectal carcinoma (HNPCC) is caused by a mutated mismatch repair (MMR) gene. The aim of our study was to determine the cumulative risk of developing ...cancer in a large series of
MSH6 mutation carriers.
Methods:
Mutation analysis was performed in 20 families with a germline mutation in
MSH6. We compared the cancer risks between
MSH6 and
MLH1/MSH2 mutation carriers. Microsatellite instability (MSI) analysis and immunohistochemistry (IHC) were performed in the available tumors.
Results:
A total of 146
MSH6 mutation carriers were identified. In these carriers, the cumulative risk for colorectal carcinoma was 69% for men, 30% for women, and 71% for endometrial carcinoma at 70 years of age. The risk for all HNPCC-related tumors was significantly lower in
MSH6 than in
MLH1 or
MSH2 mutation carriers (
P = 0.002). In female
MSH6 mutation carriers, the risk for colorectal cancer was significantly lower (
P = 0.0049) and the risk for endometrial cancer significantly higher (
P = 0.02) than in
MLH1 and
MSH2 mutation carriers. In male carriers, the risk for colorectal cancer was lower in
MSH6 mutation carriers, but the difference was not significant (
P = 0.0854). MSI analysis in colorectal tumors had a sensitivity of 86% in predicting a MMR defect. IHC in all tumors had a sensitivity of 90% in predicting a mutation in
MSH6.
Conclusions:
We recommend starting colonoscopic surveillance in female
MSH6 mutation carriers from age 30 years. Prophylactic hysterectomy might be considered in carriers older than 50 years. MSI and IHC analysis are sensitive tools to identify families eligible for
MSH6 mutation analysis.
Background Germline mutations in MSH6 account for 10%–20% of Lynch syndrome colorectal cancers caused by hereditary DNA mismatch repair gene mutations. Because there have been only a few studies of ...mutation carriers, their cancer risks are uncertain. Methods We identified 113 families of MSH6 mutation carriers from five countries that we ascertained through family cancer clinics and population-based cancer registries. Mutation status, sex, age, and histories of cancer, polypectomy, and hysterectomy were sought from 3104 of their relatives. Age-specific cumulative risks for carriers and hazard ratios (HRs) for cancer risks of carriers, compared with those of the general population of the same country, were estimated by use of a modified segregation analysis with appropriate conditioning depending on ascertainment. Results For MSH6 mutation carriers, the estimated cumulative risks to ages 70 and 80 years, respectively, were as follows: for colorectal cancer, 22% (95% confidence interval CI = 14% to 32%) and 44% (95% CI = 28% to 62%) for men and 10% (95% CI = 5% to 17%) and 20% (95% CI = 11% to 35%) for women; for endometrial cancer, 26% (95% CI = 18% to 36%) and 44% (95% CI = 30% to 58%); and for any cancer associated with Lynch syndrome, 24% (95% CI = 16% to 37%) and 47% (95% CI = 32% to 66%) for men and 40% (95% CI = 32% to 52%) and 65% (95% CI = 53% to 78%) for women. Compared with incidence for the general population, MSH6 mutation carriers had an eightfold increased incidence of colorectal cancer (HR = 7.6, 95% CI = 5.4 to 10.8), which was independent of sex and age. Women who were MSH6 mutation carriers had a 26-fold increased incidence of endometrial cancer (HR = 25.5, 95% CI = 16.8 to 38.7) and a sixfold increased incidence of other cancers associated with Lynch syndrome (HR = 6.0, 95% CI = 3.4 to 10.7). Conclusion We have obtained precise and accurate estimates of both absolute and relative cancer risks for MSH6 mutation carriers.
Background #x0026; Aims: The role of the mismatch repair gene PMS2 in hereditary nonpolyposis colorectal carcinoma (HNPCC) is not fully clarified. To date, only 7 different heterozygous truncating ...PMS2 mutations have been reported in HNPCC-suspected families. Our aim was to further assess the role of PMS2 in HNPCC. Methods: We performed Southern blot analysis in 112 patients from MLH1-, MSH2-, and MSH6-negative HNPCC-like families. A subgroup (n = 38) of these patients was analyzed by denaturing gradient gel electrophoresis (DGGE). In a second study group consisting of 775 index patients with familial colorectal cancer, we performed immunohistochemistry using antibodies against MLH1, MSH2, MSH6, and PMS2 proteins. In 8 of 775 tumors, only loss of PMS2 expression was found. In these cases, we performed Southern blot analysis and DGGE. Segregation analysis was performed in the families with a (possibly) deleterious mutation. Results: Seven novel mutations were identified: 4 genomic rearrangements and 3 truncating point mutations. Three of these 7 families fulfill the Amsterdam II criteria. The pattern of inheritance is autosomal dominant with a milder phenotype compared with families with pathogenic MLH1 or MSH2 mutations. Microsatellite instability and immunohistochemical analysis performed in HNPCC-related tumors from proven carriers showed a microsatellite instability high phenotype and loss of PMS2 protein expression in all tumors. Conclusions: We show that heterozygous truncating mutations in PMS2 do play a role in a small subset of HNPCC-like families. PMS2 mutation analysis is indicated in patients diagnosed with a colorectal tumor with absent staining for the PMS2 protein.
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