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The aim of this study was to investigate whether the activities and attitudes of general practitioners (GPs) concerning genetic counseling have changed between 1989 and 1999. In 1989 a random sample of 124 GPs in The Netherlands was selected. Of these GPs, 98 were contacted again in 1999 and 71 completed the questionnaire. The study showed an increase in the percentage of GPs who provided genetic counseling when a risk factor for having a child with a congenital disorder was present and known. In both 1989 and 1999, the GPs seldom used a recommended combination of oral and written information, and only data that was available in the databases on the risk indicator 'use of medication' increased over the years. GPs are still supporters of a directive method of counseling, and seem to believe that the main goal of genetic counseling is to prevent hereditary and congenital disorders. Although, between 1989 and 1999 more GPs provided genetic counseling when a risk indicator was present and known or referred to a clinical geneticist, only limited improvement was found in the activities of GPs to attempt to collect these data. [ABSTRACT FROM AUTHOR]

Genetically isolated populations exist worldwide. Specific genetic disorders, including rare autosomal recessive disorders may have high prevalences in these populations. We searched for Dutch genetically isolated populations and their autosomal recessive founder mutations. We investigated whether these founder mutations are covered in the (preconception) expanded carrier screening tests of five carrier screening providers. Our results show that the great majority of founder mutations are not covered in these screening panels, and these panels may thus not be appropriate for use in founder populations. It is therefore important to be aware of founder mutations in a population when offering carrier tests.

Background: Offspring of consanguineous couples are at increased risk of congenital disorders. The risk increases as parents are more closely related. Individuals that have the same degree of relatedness according to their pedigree, show variable genomic kinship coefficients. To investigate whether we can differentiate between couples with high- and low risk for offspring with congenital disorders, we have compared the genomic kinship coefficient of consanguineous parents with a child affected with an autosomal recessive disorder with that of consanguineous parents with only healthy children, corrected for the degree of pedigree relatedness., Methods: 151 consanguineous couples (73 cases and 78 controls) from 10 different ethnic backgrounds were genotyped on the Affymetrix platform and passed quality control checks. After pruning SNPs in linkage disequilibrium, 57,358 SNPs remained. Kinship coefficients were calculated using three different toolsets: PLINK, King and IBDelphi, yielding five different estimates (IBDelphi, PLINK (all), PLINK (by population), King robust (all) and King homo (by population)). We performed a one-sided Mann Whitney test to investigate whether the median relative difference regarding observed and expected kinship coefficients is bigger for cases than for controls. Furthermore, we fitted a mixed effects linear model to correct for a possible population effect., Results: Although the estimated degrees of genomic relatedness with the different toolsets show substantial variability, correlation measures between the different estimators demonstrated moderate to strong correlations. Controls have higher point estimates for genomic kinship coefficients. The one-sided Mann Whitney test did not show any evidence for a higher median relative difference for cases compared to controls. Neither did the regression analysis exhibit a positive association between case-control status and genomic kinship coefficient., Conclusions: In this case-control setting, in which we compared consanguineous couples corrected for degree of pedigree relatedness, a higher degree of genomic relatedness was not significantly associated with a higher likelihood of having an affected child. Further translational research should focus on which parts of the genome and which pathogenic mutations couples are sharing. Looking at relatedness coefficients by determining genome-wide SNPs does not seem to be an effective measure for prospective risk assessment in consanguineous parents.

Objective: Estimating the total allele frequency of all pathogenic alleles of an autosomal recessive disease is not possible if only mutational data of a sample of affected individuals are available. However, if the affected individuals come from a population where consanguinity is not uncommon, this total allele frequency can be estimated by additionally using the positive individual inbreeding coefficients or an estimate of the population inbreeding coefficient. In this paper, we propose two estimators., Methods/results: We propose to estimate the total allele frequency by a conditional maximum likelihood estimator if a part of the affected individuals in the sample comes from consanguineous marriages with known inbreeding coefficients. A simulation study shows that this estimator is unbiased and robust. We propose a second estimator which is based on an estimate of the population inbreeding coefficient. The method is applied to mutational data and individual inbreeding coefficients of Tunisian patients with congenital adrenal hyperplasia., Conclusion: Additionally using individual inbreeding coefficients or an estimate of the population inbreeding coefficient makes it possible to estimate the total allele frequency. Since consanguinity is commonly practiced in many parts of the world, the estimators proposed in the paper are of practical importance.

Consanguinity is one of the most frequent risk factors for congenital disorders. In theory, prospective exome sequencing of consanguineous couples could identify couples who both are carriers of autosomal recessive diseases, and empower such couples to make informed reproductive decisions. To investigate this, we sent blood samples to our laboratory of four pairs of consanguineous parents having one or more children affected by an autosomal recessive disorder, without revealing any diagnostic information. The study was restricted to find identical, previously described, or evidently pathogenic mutations in both parents of each couple, in over 400 genes known to result in severe autosomal recessive disorders. Out of the six autosomal recessive disorders known to the four couples studied, two were correctly identified. Carrier status of one not previously known autosomal recessive disorder was discovered. As expected, given the pipeline used, large deletions, mutations in genes not present in the gene list, mutations outside the exons and consensus splice sites, and mutations that were not evidently pathogenic and previously not reported, were not identified. The restriction to detecting only couples with identical mutations diminishes the risk of revealing unsolicited findings and shortens the time needed for analysis, but also results in missing couples with different mutations in the same gene. In addition to the proposed pipeline, couples should be offered testing for carrier status of frequent disorders that can present themselves by large deletions, non-exonic mutations or compound heterozygous mutations (e.g. thalassemia, spinal muscular atrophy, cystic fibrosis). Even though sensitivity is reduced, offering exome sequencing prospectively will increase reproductive options for consanguineous couples., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Consanguineous couples should be adequately informed about their increased reproductive risk and possibilities for genetic counselling. Information may only be effective if it meets the needs of the target group. This study aimed to gain more insight into: (1) attitudes of people belonging to ethnic groups in Western society towards consanguinity and their understanding of risk for offspring; and (2) their attitudes regarding reproductive information targeted at consanguineous couples. Dutch Moroccans and Turks were invited to complete an online questionnaire by snowball sampling and by placing a link on two popular Dutch Moroccan/Turkish forum websites between September and October 2011. The questionnaire was completed by 201 individuals who were, on average, neither positive nor negative towards consanguinity. Respondents with a consanguineous partner were more positive, estimated the risk for the offspring lower and were less positive about the provision of risk information to consanguineous couples when compared with respondents without a consanguineous partner. Participants of Turkish origin had a more negative attitude towards consanguinity and estimated the reproductive risk higher than Moroccan participants. More than half of the respondents thought that information should be given before marriage, whereas only 10% thought it should never be provided. The general practitioner was most often mentioned (54%) as the designated professional to inform people. Information about genetic risks related to consanguinity should be offered early, preferably before marriage. The diversity of the target population requires various strategies to disseminate information and reach consanguineous couples with the offer of genetic counselling.

This paper reviews what is currently known about the presence of consanguinity and endogamy in the Netherlands, in the past and today, and concludes with a discussion of medical genetic aspects. First geographic characteristics, the demographic history, the genetic make-up of the native population, legal aspects and the public opinion are reviewed. Then data on the prevalence of consanguinity in the native population are presented for marriages since 1840, followed by data on consanguineous marriages among immigrants from countries with a tradition of close-kin marriages. It is estimated that approximately 1% of at-risk consanguineous couples are referred to clinical genetic centres for prospective genetic counselling in the Netherlands. This picture will change dramatically if and when next-generation sequencing is introduced to identify couples at ≥ 25% risk prospectively., (© 2014 S. Karger AG, Basel.)

In this short communication we (1) show that, despite the rarity of autosomal recessive inheritance, primary congenital hydrocephalus in a girl stemming from father-daughter incest is most likely due to the incestuous union of her parents, and (2) reflect on the question, among others, whether actual genetic work-up to support victim indemnification is ever in the interest of the child., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Background: It is often suggested that an effort must be made to increase awareness among consanguineous couples of their reproductive risk, and to refer them for genetic counseling if needed. Primary care professionals are considered most appropriate for addressing the subject and identifying couples at risk during consultations in their practice. This Dutch study aims to explore the experiences, attitudes and beliefs of such professionals regarding their care for consanguineous couples., Methods: Sixteen semi-structured interviews were conducted with midwives and general practitioners., Results: Although most primary care professionals considered it their task to inform couples about the risks of consanguinity, during consultations the topic was generally only briefly touched upon and quickly abandoned. Important reasons for this were professionals' beliefs about religious and social values of couples, their low perception of the couples' reproductive risk and expected limited feasibility of referral. Feelings of embarrassment regarding addressing consanguinity did not seem to play a significant role., Conclusions: Primary care professional beliefs about their clients' religious and social values, their attitudes toward the risk, and perceived limited options for referral seem to conflict with the professional norm to address the topic of consanguinity.

In this paper I will review different aspects of genetic risk in the context of preconception care. I restrict myself to the knowledge of risk which is relevant for care and/or enables reproductive choice. The paper deals with chromosomes, genes and the genetic classification of diseases, and it explains why Mendelian disorders frequently do not show the expected pattern of occurrence in families. Factors that amplify genetic risk are also discussed. Of the two methods of genetic risk assessment-history taking and genetic screening-the former method is examined to some extent, and the consequences of an inadequate family history are illustrated in a case report. The paper ends with a review of the sparse literature available on the frequency of a positive family history and an outline of the challenges and rewards faced by professionals when confronted with a positive history.

The 17q21.31 microdeletion syndrome is characterised by intellectual disability, epilepsy, distinctive facial dysmorphism, and congenital anomalies. To date, all individuals reported with this syndrome have been simplex patients, resulting from de novo deletions. Here, we report sibling recurrence of the 17q21.31 microdeletion syndrome in two independent families. In both families, the mother was confirmed to be the parent-of-origin for the 17q21.31 deletion. Fluorescence in situ hybridisation analyses in buccal mucosa cells, of the mother of family 1, identified monosomy 17q21.31 in 4/50 nuclei (8%). In mother of family 2, the deletion was identified in 2/60 (3%) metaphase and in 3/100 (3%) interphase nuclei in peripheral lymphocytes, and in 7/100 (7%) interphase nuclei in buccal cells. A common 17q21.31 inversion polymorphism predisposes to non-allelic homologous recombination and hereby to the 17q21.31 microdeletion syndrome. On the basis of the 17q21.31 inversion status of the parents, we calculated that the probability of the second deletion occurring by chance alone was 1/14,438 and 1/4812, respectively. If the inversion status of the parents of a child with the 17q21.31 microdeletion syndrome is unknown, the overall risk of a second child with the 17q21.31 microdeletion is 1/9461. We conclude that the presence of low-level maternal somatic-gonadal mosaicism is associated with the microdeletion recurrence in these families. This suggests that the recurrence risk for parents with a child with a 17q21.31 microdeletion for future pregnancies is higher than by chance alone and testing for mosaicism in the parents might be considered as a helpful tool in the genetic counselling.

When in 2007 it became clear that the Karger journal Community Genetics would change its name and scope, the first author started to establish an international, multidisciplinary e-mail network and a newsletter with papers authored by the members of the network. This paper reports on the first 3 years of the network. At the end of the 3-year period, there were 858 members, 50 newsletters had appeared, and almost 1,500 different papers from 458 journals had been cited. This model may serve as an example for others who want to bring together those sharing a common interest.

Recently, a number of commercial companies are offering preconceptional carrier tests directly-to-consumers. This offer raises a number of concerns and issues above and beyond those encountered with preconceptional tests offered within the traditional health care setting. In order to bring some of these issues to light and to initiate dialogue on this topic, this article discusses the following issues: the current offer of preconceptional carrier tests (until the end of 2010) through online commercial companies; the implications for the informed consent procedure and the need for good information; the need for medical supervision and follow-up; and the appropriate use of existing resources. The article concludes with some reflections about the potential sustainability of the offer of preconceptional carrier tests directly-to-consumers.

Western health care systems are facing today increasing movement of genetic knowledge from research labs into clinical practice. This paper reports the results of a survey that addressed the confidence of primary care physicians in their ability to carry out basic medical genetic tasks. The survey was conducted in five countries (France, Germany, The Netherlands, Sweden and the UK). Stratified random samples were drawn from primary care physicians in the five countries representing a sampling frame of 139,579 physicians. Stepwise binary logistic regression procedures were performed to identify the predictor variables for self-reported confidence. Three thousand six hundred eighty-six physicians participated and filled out a self-administered questionnaire. The margin of error for accurate representation of each group of European general practitioners and specialists in the total sample is 2.9% for GP, 2.8% for obstetricians/gynaecologists (OB/GYN) and for paediatricians (PAED) 2.6% (95% confidence level). Confidence in their ability to carry out basic medical genetic tasks is low among participating primary care physicians: 44.2% are not confident, 36.5% somewhat confident, confident or very confident are 19.3%. In each country, those confident/very confident represent less than 33% of the participating physicians. Primary care physicians who report the lowest levels of confidence prove to be those least exposed to medical genetics information and training. Although there are significant differences in the way in which professional education is organised and practice is regulated across European countries, there is a need for a coordinated European effort to improve primary care physicians' background in medical genetics.

Background: The offspring of consanguineous relations have an increased risk of congenital/genetic disorders and early mortality. Consanguineous couples and their offspring account for approximately 10% of the global population. The increased risk for congenital/genetic disorders is most marked for autosomal recessive disorders and depends on the degree of relatedness of the parents. For children of first cousins the increased risk is 2-4%. For individual couples, however, the extra risk can vary from zero to 25% or higher, with only a minority of these couples having an increased risk of at least 25%. It is currently not possible to differentiate between high-and low-risk couples. The quantity of DNA identical-by-descent between couples with the same degree of relatedness shows a remarkable variation. Here we hypothesize that consanguineous partners with children affected by an autosomal recessive disease have more DNA identical-by-descent than similarly-related partners who have only healthy children. The aim of the study is thus to establish whether the amount of DNA identical-by-descent in consanguineous parents of children with an autosomal recessive disease is indeed different from its proportion in consanguineous parents who have healthy children only., Methods/design: This project is designed as a case-control study. Cases are defined as consanguineous couples with one or more children with an autosomal recessive disorder and controls as consanguineous couples with at least three healthy children and no affected child. We aim to include 100 case couples and 100 control couples. Control couples are matched by restricting the search to the same family, clan or ethnic origin as the case couple. Genome-wide SNP arrays will be used to test our hypothesis., Discussion: This study contains a new approach to risk assessment in consanguineous couples. There is no previous study on the amount of DNA identical-by-descent in consanguineous parents of affected children compared to the consanguineous parents of healthy children. If our hypothesis proves to be correct, further studies are needed to obtain different risk figure estimates for the different proportions of DNA identical-by-descent. With more precise information about their risk status, empowerment of couples can be improved when making reproductive decisions.

It is increasingly recognised that genetics will have to be integrated into all parts of primary health care. Previous research has demonstrated that involvement and confidence in genetics varies amongst primary care providers. We aimed to analyse perceptions of primary care providers regarding responsibility for genetic tasks and factors affecting those perceptions. Postal questionnaire including a hypothetical case management scenario of a cardiac condition with a genetic component was sent to random samples of medically qualified general practitioners in France, Germany, Netherlands, Sweden and UK (n = 1,168). Logistic regression analysis of factors affecting primary care practitioners' willingness to carry out genetic tasks themselves was conducted; 61% would take a family history themselves but only 38% would explain an inheritance pattern and 16% would order a genetic test. In multivariate analysis, only the country of practice was consistently predictive of willingness to carry out genetic tasks, although male gender predicted willingness to carry out the majority of tasks studied. The stage of career at which education in genetics had been provided was not predictive of willingness to carry out any of the tasks analysed. Country of practice is significantly predictive of attitudes towards genetics in primary care practice and therefore genetic education structure and content in Europe will need to be significantly tailored towards country-specific approaches.

This paper presents an overview of the conclusions from an international conference convened to address current issues related to the provision of Cystic Fibrosis carrier screening within Europe. Consensus was not aimed at stating whether such a programme should be implemented. Instead the focus was to provide a framework for countries and agencies who are considering or planning its establishment. The general principles and target population of Cystic Fibrosis carrier screening, advantages and disadvantages, health economics, monitoring and future evaluative and research directions were covered. A range of screening strategies have been assessed and compared: pre-conceptional and prenatal screening; individual and couple screening; sequential and simultaneous sampling or testing. Furthermore, technical issues were examined with respect to the choice of the panel of mutations, its detection rate, sensitivity, management of intermediate 'at-risk' couples, screening approach to different populations and ethnic minorities, and assurance of laboratory quality control. The consensus statement also aims to establish the benchmarks for communicating with health care providers, the general public and potential and actual participants before and after the genetic test.

This paper presents a definition of the medical field of community genetics. It starts with a brief historical overview, defines the requirements for an adequate definition, presents the definition, and discusses the constituent parts of the definition.

This short communication deals with the questions of how to calculate the expected proportion of compound heterozygous patients among affected offspring of consanguineous parents, and how, from an observed proportion of compound heterozygotes, to calculate both the proportion of homozygotes not identical by descent and the frequency of pathogenic alleles in the population. This estimate of allele frequency may be useful when dealing with populations with a considerable number of consanguineous matings.

Objective: to investigate whether practising midwives are adequately prepared to integrate genetic information into their practice., Design: a cross-sectional, postal, structured questionnaire survey was sent to practising midwives., Setting: practising midwives from the Netherlands (NL), Sweden (SE) and the United Kingdom (UK)., Participants: 1021 replies were received, achieving a response rate of 62%., Findings: 79% (799/1015) of midwives reported attending courses with some 'genetic content' during their initial training. Sixty-eight per cent (533/784) judged this to have been useful for clinical practice. Variation was seen between countries in the amount of genetic content in post-registration training (SE 87%, NL 44%, UK 17%) and most was considered useful. Questions assessing clinical activity identified a current need for genetic knowledge. Midwives described low levels of self-reported confidence both in overtly genetic procedures and in everyday tasks that were underpinned by genetic knowledge. For eight of the 12 procedures, fewer than 20% of midwives considered themselves to be confident. Differences were apparent between countries. Midwives identified psychosocial, screening and risk assessment aspects of genetic education as being important to them, rather than technical aspects or genetic science., Conclusions: given the low reported confidence with genetic issues in clinical practice, it is essential that this is addressed in terms of the amount, content and targeting of genetic education. This is especially important to ensure the success of national antenatal and baby screening programmes. The results of this study suggest that midwives would welcome further training in genetics, addressing genetic topics most relevant to their clinical practice.

This paper explores determinants of the intention to participate or not and of actual participation in preconceptional ancestry-based carrier couple screening for cystic fibrosis (CF) and haemoglobinopathies (HbPs). In total, 9453 individuals from a multi-ethnic population were invited. Invitees who had a partner and who were planning a pregnancy were the target population (33-36%). Test participation was conditional on survey participation. Those who refrained from test participation were asked to participate in the survey only. The questionnaire was based on the Theory of Planned Behaviour, which explains behaviour through intention. It was completed by 418 survey participants: 171 who intended to participate in the testing, and 247 who refrained from test participation. Both test intenders and offer decliners generally had a positive attitude towards test participation, and perceived high behavioural control. This applied to Western and non-Western survey participants equally. Offer decliners, however, perceived less control in terms of the time and effort needed for participation. Still, 68% of them intended to participate in the future if the screening would be offered routinely. Test intenders more often would draw reproductive consequences from test results, perceived a higher risk of being a carrier, more benefits and less adverse psychological outcomes. Feelings of stigmatisation were not an important issue, but 14% thought that there would be discrimination against carriers: among them more were non-Western survey participants. Preconceptional ancestry-based CF and HbPs carrier screening was evaluated as positive and desirable among Western and non-Western survey participants. The effort and time needed for participation were important reasons for declining participation, which might be overcome by improving access to the screening.

Background: Within Europe many guidelines exist regarding the genetic testing of minors. Predictive and presymptomatic genetic testing of minors is recommended for disorders for which medical intervention/preventive measures exist, and for which early detection improves future medical health., Aim: This study, which is part of the larger 5th EU-framework "genetic education" (GenEd) study, aimed to evaluate the self-reported responses of nongenetic health-care providers in five different EU countries (Germany, France, Sweden, the United Kingdom, and the Netherlands) when confronted with a parent requesting presymptomatic testing on a minor child for a treatable disease., Methods: A cross-sectional study design using postal, structured scenario-based questionnaires that were sent to 8129 general practitioners (GPs) and pediatricians, between July 2004 and October 2004, addressing self-reported management of a genetic case for which early medical intervention during childhood is beneficial, involving a minor., Results: Most practitioners agreed on testing the oldest child, aged 12 years (81.5% for GPs and 87.2% for pediatricians), and not testing the youngest child, aged 6 months (72.6% for GPs and 61.3% for pediatricians). After multivariate adjustment there were statistical differences between countries in recommending a genetic test for the child at the age of 8 years. Pediatricians in France (50%) and Germany (58%) would recommend a test, whereas in the United Kingdom (22%), Sweden (30%), and the Netherlands (32%) they would not., Conclusion: Even though presymptomatic genetic testing in minors is recommended for disorders for which medical intervention exists, EU physicians are uncertain at what age starting to do so in young children.