Family system characteristics and psychological adjustment to cancer susceptibility genetic testing: a prospective study.

This study examined prospectively the contribution of family functioning, differentiation to parents, family communication and support from relatives to psychological distress in individuals undergoing genetic susceptibility testing for a known familial pathogenic BRCA1/2 or Hereditary nonpolyposis colorectal cancer-related mutation. Family functioning, differentiation to parents, hereditary cancer-related family communication and perceived support from relatives were assessed in 271 participants for genetic testing before test result disclosure. Hereditary cancer distress (assessed by the Impact of Event Scale) and cancer worry (assessed by the Cancer Worry Scale) were assessed before, 1 week after, and 6 months after test result disclosure. Participants reporting more cancer-related distress over the study period more frequently perceived the communication about hereditary cancer with relatives as inhibited, the nuclear family functioning as disengaged-rigid or enmeshed-chaotic, the support from partner as less than adequate and the relationship to mother as less differentiated. Especially, open communication regarding hereditary cancer and partner support may be important buffers against hereditary cancer distress. Identifying individuals with insufficient sources of support and addressing the family communication concerning hereditary cancer in genetic counseling may help the counselee to adjust better to genetic testing.

Experience of parental cancer in childhood is a risk factor for psychological distress during genetic cancer susceptibility testing.

BACKGROUND: This study explores the effect of age at the time of parental cancer diagnosis or death on psychological distress and cancer risk perception in individuals undergoing genetic testing for a specific cancer susceptibility. PATIENTS AND METHODS: Cancer-related distress, worry and risk perception were assessed in 271 applicants for genetic testing of an identified mutation in BRCA1/2 (BReast CAncer) or a HNPCC (Hereditary Nonpolyposis Colorectal Cancer) related gene before, one week after, and six months after genetic test disclosure. The course of distress and risk perception were compared between individuals having witnessed parental cancer or loss due to cancer in childhood, adolescence, adulthood and having unaffected parents. RESULTS: Individuals with parental cancer in childhood (under age 13) reported the highest level of cancer related distress, worry and risk perception. Women having their mother affected by breast cancer in puberty (aged 10-13 years) perceived higher breast cancer risks than women with an affected mother in adulthood or without an affected mother. Individuals with an affected parent perceived cancer risks as higher than individuals without an affected parent, but were not more distressed. CONCLUSIONS: Experience of parental cancer in childhood is a risk factor for psychological distress during the genetic testing process.

Multiplicity in polyp count and extracolonic manifestations in 40 Dutch patients with MYH associated polyposis coli (MAP).

OBJECTIVE: To investigate the contribution of MYH associated polyposis coli (MAP) among polyposis families in the Netherlands, and the prevalence of colonic and extracolonic manifestations in MAP patients. METHODS: 170 patients with polyposis coli, who previously tested negative for APC mutations, were screened by denaturing gradient gel electrophoresis and direct sequencing to identify MYH germline mutations. RESULTS: Homozygous and compound heterozygous MYH mutations were identified in 40 patients (24%). No difference was found in the percentage of biallelic mutation carriers between patients with 10-99 polyps or 100-1000 polyps (29% in both groups). Colorectal cancer was found in 26 of the 40 patients with MAP (65%) within the age range 21 to 67 years (median 45). Complete endoscopic reports were available for 16 MAP patients and revealed five cases with gastro-duodenal polyps (31%), one of whom also presented with a duodenal carcinoma. Breast cancer occurred in 18% of female MAP patients, significantly more than expected from national statistics (standardised morbidity ratio = 3.75). CONCLUSIONS: Polyp numbers in MAP patients were equally associated with the attenuated and classical polyposis coli phenotypes. Two thirds of the MAP patients had colorectal cancer, 95% of whom were older than 35 years, and one third of a subset of patients had upper gastrointestinal lesions. Endoscopic screening of the whole intestine should be carried out every two years for all MAP patients, starting from age 25-30 years. The frequent occurrence of additional extraintestinal manifestations, such as breast cancer among female MAP patients, should be thoroughly investigated.

Increased prevalence of catecholamine excess and phaeochromocytomas in a well-defined Dutch population with SDHD-linked head and neck paragangliomas.

OBJECTIVE: The aim of this study was to identify the prevalence of catecholamine excess and phaeochromocytomas in a well-defined population of people with hereditary head and neck paragangliomas. METHODS: We studied in a prospective follow-up protocol all consecutive patients referred to the Department of Endocrinology, Leiden University Medical Center, Leiden, The Netherlands with documented head and neck paragangliomas and either a positive family history for paragangliomas or a proven SDHD gene mutation. Initial analysis included medical history, physical examination and the measurement of excretion of catecholamines in two 24-h urine collections. In the case of documented catecholamine excess iodinated meta-iodobenzylguanidine (123I-MIBG) scintigraphy and magnetic resonance imaging were done. RESULTS: Between 1988 and 2003, 40 consecutive patients (20 male and 20 female) with documented head and neck paragangliomas were screened. Biochemical screening revealed urinary catecholamine excess in 15 patients (37.5%). In nine of these 15 patients a lesion was found by 123I-MIBG scintigraphy. Exact localization by magnetic resonance imaging revealed phaeochromocytomas in seven of the 15 patients. One of the nine patients had an extra-adrenal paraganglioma. Histopathological examination in a subset of tumors displayed loss of heterozygosity of the wild-type SDHD allele in all cases. CONCLUSIONS: The prevalence of catecholamine excess (37.5%) and phaeochromocytomas (20.0%) is high in patients with familial head and neck paragangliomas. Therefore, patients with hereditary head and neck paragangliomas require lifelong follow up by biochemical testing for catecholamine excess.

Identification of HNPCC by molecular analysis of colorectal and endometrial tumors.

Hereditary nonpolyposis colorectal cancer (HNPCC, Lynch syndrome) is a dominantly inherited syndrome characterized by the development of colorectal cancer, endometrial cancer and other cancers and the presence of microsatellite instability (MSI) in tumors. The Bethesda guidelines have been proposed for the identification of families suspected of HNPCC that require further molecular analysis. We have evaluated the yield of MSI-analysis in a large series of Dutch families suspected of HNPCC. We also analysed whether the loss of mismatch repair (MMR) protein detected by immunohistochemistry (IHC) of colorectal cancer (CRC) and endometrial cancer correlated with the presence of MSI and/or a MMR gene mutation. The results showed that the Bethesda criteria with a few modifications are appropriate to identify families eligible for genetic testing. In addition, we found that MSI and IHC-analysis of CRC using antibodies against MLH1, MSH2, MSH6 and PMS2 proteins are equally effective for identifying carriers of the known MMR gene defects. However, as long as the role of other putative MMR genes in hereditary CRC has not been elucidated, IHC-analysis cannot completely replace MSI. For this reason, we prefer MSI-analysis as first step in families suspected of HNPCC. On the other hand, in families fulfilling the revised Amsterdam criteria in which the probability of detecting a mutation is relatively high, we would recommend IHC as first diagnostic step because the result might predict the specific underlying MMR gene mutation. MSI or IHC-analysis of endometrial cancer alone was found to be less sensitive compared with these tests performed in colorectal cancer. Therefore, probably the best approach in the analysis of this cancer is to perform both techniques. The identification of HNPCC is important as it makes it possible to target effective preventative measures. Our studies showed that MSI and IHC analysis of colorectal and endometrial cancer, are reliable cost-effective tools that can be used to identify patients with HNPCC.

[Widely divergent clinical phenotype of x-linked agammaglobulinemia in two cousins]. / Groot verschil in klinisch fenotype van X-gebonden agammaglobulinemie bij twee neefjes.

X-linked agammaglobulinaemia (XLA) is a primary immunodeficiency caused by a mutation in the gene encoding Bruton's tyrosine kinase (BTK). The classical presentation of XLA consists of the almost complete absence of B-lymphocytes and immunoglobulins in the peripheral blood leading to severe, mainly bacterial, upper and lower respiratory-tract infections already in early childhood. Irrespective of the kind of BTK-gene mutation the phenotype of XLA can be very diverse. Two 9-year-old cousins with the same BTK-gene mutation illustrate this phenotypical diversity. One boy had a classical presentation and was on maintenance treatment with intravenous immunoglobulins and prophylactic antibiotics to control his infections. Without any prophylactic treatment, his cousin had no abnormal infectious course despite very low B-lymphocyte counts and immunoglobulin levels in the blood. The mechanisms underlying the phenotypical diversity of XLA have not been clarified. Gene polymorphisms affecting the innate immune system may play a role.

Bannayan-Riley-Ruvalcaba syndrome: further delineation of the phenotype and management of PTEN mutation-positive cases.

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is characterised by macrocephaly, intestinal hamartomatous polyps, lipomas, pigmented maculae of the glans penis, developmental delay and mental retardation. The syndrome follows an autosomal dominant pattern of inheritance. In 1997 reports on two BRRS patients with a deletion at 10q23.2-q24.1 were published. In the same year, the first two families with BRRS and a mutation of the PTEN gene were reported. Mutations in the PTEN gene have also been demonstrated in patients with Cowden syndrome (CS), which shows partial clinical overlap with BRRS, and in families with cases both of BRRS and CS. PTEN mutation positive BRRS and CS are likely to be different phenotypic presentations of the same syndrome. If BRRS and CS are one single condition, the question arises whether patients with BRRS should be screened for malignant tumours, since patients with Cowden syndrome have an increased risk of breast, endometrial, thyroid and renal cancer. We present two isolated cases and one family and confirm that BRRS and CS are allelic. Furthermore, we review the PTEN mutation positive BRRS cases, to further delineate the phenotype and to compare the cases with a genomic deletion with the cases with a point mutation. We recommend offering BRRS cases with a mutation in PTEN the same surveillance protocol for (malignant) tumours as is currently recommended for CS. In addition, we propose a yearly haemoglobin test from early infancy for the early detection of intestinal hamartomas, which are likely to give severe complications, especially in BRRS cases.

[From gene to disease; from SDHD, a defect in the respiratory chain, to paragangliomas and pheochromocytomas]. / Van gen naar ziekte; van SDHD, een defect in de ademhalingsketen, naar paragangliomen en feochromocytomen.

Hereditary paragangliomas are rare benign tumours arising from neuroectodermal tissue in the head and neck region. In families with paraganglioma, occasionally adrenal and extra-adrenal pheochromocytomas are found. Paragangliomas, adrenal and extra-adrenal pheochromocytomas may be caused by mutations in the SDHB, SDHC and SDHD genes encoding different subunits of mitochondrial respiratory chain complex II. Most paraganglioma cases in the Netherlands are caused by SDHD mutations. Presymptomatic DNA diagnosis is available for families with paragangliomas caused by SDHD mutations.

[Prenatal diagnosis for hereditary predisposition to mammary and ovarian carcinoma--defining a position]. / Prenatale diagnostiek naar de erfelijke aanleg voor mamma-/ovariumcarcinoom--een standpuntbepaling.

Prenatal testing for a BRCA mutation, the hereditary trait for mammary and ovarian carcinoma, with the intention of selective termination of pregnancy in case of a female carrier is a controversial ethical issue. Based on a review of the (limited) medical literature as well as of Dutch policy statements relating to this subject, the following conclusions and recommendations are proposed: (a) the decision to opt for prenatal BRCA testing and selective termination of pregnancy in case of a BRCA mutation in the foetus cannot immediately be judged unacceptable from an ethical point of view; (b) prenatal BRCA testing is morally defensible only in case of a female foetus and if the parents at least have the intention to terminate the pregnancy if the foetus is a carrier, although the final decision is in any case up to the parents only; (c) prental testing for a BRCA mutation should only be done after extensive counselling of the parents, during which not only the medical genetic aspects but also the ethical aspects of prenatal BRCA testing are discussed.

Bias in detection of instability of the (C)8 mononucleotide repeat of MSH6 in tumours from HNPCC patients.

Recently, we and others reported instability in the (C)8 repeat in exon 5 of MSH6 as a preferential target for somatic mutations in tumours from MSH6 germline mutation carriers. Here, we report that in 45% of tumours from MLH1, MSH2 and MSH6 germline mutation carriers no sequence change in the (C)8 repeat of MSH6 was found upon DNA sequencing analysis of PCR products with a shift in electrophoresis mobility. Using "standard" PCR primers a high frequency of instability (50-86%) of the (C)8 repeat was found, but using a modified PCR reverse primer, accomplishing modulation of non-templated addition of adenine during in vitro PCR amplification by the Taq polymerase, a markedly lower frequency of instability was found in tumours from MLH1, MSH2 and MSH6 mutation carriers (6, 13 and 40%, respectively). Furthermore, a significant difference of the frequency of instability of the (C)8 repeat in tumours from MSH6 mutation carriers was found compared to MLH1, MSH2 mutation carriers. These results might have important implications for the detection of instability of other short mononucleotide repeats, e.g. TGFbetaRII, BAX, IGFRII, PTEN, BRCA2.

Nearly all hereditary paragangliomas in the Netherlands are caused by two founder mutations in the SDHD gene.

Hereditary paragangliomas or glomus tumors are usually benign slow-growing tumors in the head and neck region. The inheritance pattern of hereditary paraganglioma is autosomal dominant with imprinting. Recently, we have identified the SDHD gene encoding subunit D of the mitochondrial respiratory chain complex II as one of the genes involved in hereditary paragangliomas. Here, we demonstrate that two founder mutations, Asp92Tyr and Leu139Pro, are responsible for paragangliomas in 24 and 6 of the 32 independently ascertained Dutch paraganglioma families, respectively. These two mutations were also detected among 20 of 55 isolated patients. Ten of the isolated patients had multiple paragangliomas, and in eight of these SDHD germline mutations were found, indicating that multicentricity is a strong predictive factor for the hereditary nature of the disorder in isolated patients. In addition, we demonstrate that the maternally derived wild-type SDHD allele is lost in tumors from mutation-carrying patients, indicating that SDHD functions as a tumor suppressor gene.

Atypical HNPCC owing to MSH6 germline mutations: analysis of a large Dutch pedigree.

Hereditary non-polyposis colorectal cancer (HNPCC) is the most common genetic susceptibility syndrome for colorectal cancer. HNPCC is most frequently caused by germline mutations in the DNA mismatch repair (MMR) genes MSH2 and MLH1. Recently, mutations in another MMR gene, MSH6 (also known as GTBP), have also been shown to result in HNPCC. Preliminary data indicate that the phenotype related to MSH6 mutations may differ from the classical HNPCC caused by defects in MSH2 and MLH1. Here, we describe an extended Dutch HNPCC family not fulfilling the Amsterdam criteria II and resulting from a MSH6 mutation. Overall, the penetrance of colorectal cancer appears to be significantly decreased (p<0.001) among the MSH6 mutation carriers in this family when compared with MSH2 and MLH1 carriers (32% by the age of 80 v >80%). Endometrial cancer is a frequent manifestation among female carriers (six out of 13 malignant tumours). Transitional cell carcinoma of the urinary tract is also relatively common in both male and female carriers (10% of the carriers). Moreover, the mean age of onset of both colorectal cancer (MSH6 v MSH2/MLH1 = 55 years v 44/41 years) and endometrial carcinomas (MSH6 v MSH2/MLH1 = 55 years v 49/48 years) is delayed. As previously reported, we confirm that the pattern of microsatellite instability, in combination with immunohistochemical analysis, can predict the presence of a MSH6 germline defect. The detailed characterisation of the clinical phenotype of this kindred contributes to the establishment of genotype-phenotype correlations in HNPCC owing to mutations in specific mismatch repair genes.

Prediction of a mismatch repair gene defect by microsatellite instability and immunohistochemical analysis in endometrial tumours from HNPCC patients.

Instability of microsatellite repeat sequences has been observed in colorectal carcinomas and in extracolonic malignancies, predominantly endometrial tumours, occurring in the context of hereditary non-polyposis colorectal cancer (HNPCC). Microsatellite instability (MSI) as a feature of human DNA mismatch repair (MMR)-driven tumourigenesis of the uterine mucosa has been studied primarily in sporadic tumours showing predominantly somatic hypermethylation of MLH1. The present study shows that all endometrial carcinomas (n=12) from carriers of MLH1 and MSH2 germline mutations demonstrate an MSI-high phenotype involving all types of repeat markers, while in endometrial carcinomas from MSH6 mutation carriers, only 36% (4 out of 11) demonstrate an MSI-high phenotype. Interestingly, an MSI-high phenotype was found in endometrial hyperplasias from MSH2 mutation carriers, in contrast to hyperplasias from MLH1 mutation carriers, which exhibited an MSI-stable phenotype. Instability of only mononucleotide repeat markers was found in both endometrial carcinomas and hyperplasias from MSH6 mutation carriers. In 29 out of 31 (94%) endometrial tumour foci, combined MSI and immunohistochemical analysis of MLH1, MSH2, and MSH6 could predict the identified germline mutation. The observation of MSI in endometrial hyperplasia and of altered protein staining for the MMR genes supports the idea that inactivation of MMR genes is an early event in endometrial tumourigenesis. A correlation was found between the variation in the extent and level of MSI and the age of onset of carcinoma, suggesting differences in the rate of tumour progression. A high frequency of MSI in hyperplasias, found only in MSH2 mutation carriers, might indicate a more rapid tumour progression, correlating with an earlier age of onset of carcinoma. The present study indicates that assessment of altered protein staining combined with MSI analysis of endometrial tumours might direct the mutational analysis of MMR genes.

A near false-negative finding of mosaic trisomy 21--a cautionary tale.

We report the finding of a mosaic trisomy 21 restricted to the long-term culture of chorionic villi and to one amniotic fluid culture which, if interpreted according to the standard rules for the authentication of mosaicism, would have resulted in a false-negative result. The definitive diagnosis of mosaic Down syndrome was eventually confirmed by cordocentesis and by post-abortion fibroblast cultures.

The use of preventive health care services: carrier testing for the genetic disorder haemophilia.

A retrospective study was performed to explore carrier testing among women who were possible or obligate carriers of the haemophilia gene. Knowledge of the possibility of carrier testing and use of carrier testing were studied separately. In our exploration we were guided by the diffusion theory and the Health Belief Model. Logistic regression analysis showed that four factors were statistically significant related to knowledge of carrier testing: information via mass media, a haemophilic relative in the nuclear family rather than in the extended family, medical severity of haemophilia, and information from the patients' organization. For those women acquainted with carrier testing two of the four factors just mentioned were significantly related to the utilization of carrier testing i.e. having a haemophilic relative in the nuclear family and the medical severity of the haemophilia. In addition the following factors were associated: attitude towards abortion because of haemophilia, educational level, and marital status. Notwithstanding the prominent function of the mass media and the patients' organization, the respondents themselves stated that relatives, especially parents and sisters, were the most important source of information on genetic counselling and carrier testing.

The contribution of DNA analysis to carrier detection and prenatal diagnosis of hemophilia A and B.

Developments in DNA technology have provided a novel means of carrier detection and prenatal diagnosis of hemophilia A and B. The collection of a large set of data has enabled us to evaluate the present feasibility and reliability of a diagnosis at the gene level and its contribution to methods already available. Since 1984, 533 potential and obligate carriers belonging to 170 families with hemophilia have been referred to us. By the combined use of pedigree analysis, coagulation assays, and DNA (RFLP) analysis, certainty about the carrier status has been markedly increased for the potential carriers. Although RFLP analysis revealed the possible origin of the mutation in many families with an isolated patient, uncertainty remained for quite a number of their female relatives because of the possible occurrence of germline mosaicism. Forty-one women requested prenatal diagnosis during one or more pregnancies. The short time interval between pregnancies, even after abortion of an affected fetus, proved that first-trimester prenatal diagnosis has become an acceptable option for women at risk. Recently, efficient methods for direct identification of mutations have been developed, and they may allow a definite diagnosis for all families with hemophilia in the near future.

Sex ratio of the mutation frequencies in haemophilia A: coagulation assays and RFLP analysis.

Coagulation and RFLP data from 41 families with an isolated haemophilia A patient were used to estimate the sex ratio of mutation frequencies (nu/mu). Based on the results of coagulation assays in all the female relatives investigated, nu/mu was estimated to be 12.1 by the maximum likelihood method (95% confidence interval 3.8 to 62.5). In order to avoid the possible influence of germline mosaicism, an additional analysis was performed in which only the results in the mothers and grandmothers of an isolated patient were included. The nu/mu ratio was then estimated to be 5.2 (95% confidence interval 1.8 to 15.1). Because an estimate of nu/mu based on all available RFLP data can easily be biased in favour of males, we set up a model in which only information on the grandparental derivation of the patient's X chromosome was used, irrespective of the generation in which the mutation actually occurred. In this way nu/mu was estimated to be minimally 4. The probability of carriership for mothers of an isolated haemophilia A patient amounts to 86% with a sex ratio of 5.2. Although this would imply that 14% of the mothers are not carriers of the disease in the classical sense, they may be mosaic for the mutation and, therefore, also at risk of transmitting the mutation more than once.