Reproductive attitudes of couples having a child with cystic fibrosis in Saguenay-Lac-Saint-Jean (Quebec, Canada)

Cystic fibrosis (CF) has a high incidence (1/936 live births) and carrier rate (1/15 inhabitants) in Saguenay-Lac-Saint-Jean. One objective of a major enquiry among several subsets of individuals from this high-risk population for CF was to evaluate the reproductive behaviour of couples with a CF child attending the comprehensive CF clinic in Chicoutimi. The knowledge of the recurrence risk resulted in deciding against further progeny or in reducing the number of children. More reliable contraception methods after the birth of the CF child, but not prenatal diagnosis, were used. Although a minority of parents with a CF child would abort a CF foetus, they apparently started viewing pregnancy interruption for CF after prenatal diagnosis as an acceptable reproductive option.     

Preconceptional cystic fibrosis carrier screening: attitudes and intentions of the target population

The aim of this study was to assess the attitudes and intentions of individuals planning a pregnancy with regard to preconceptional cystic fibrosis (CF) carrier screening and to determine factors associated with a positive and negative/neutral intention to have the test. A survey, based on a questionnaire, was conducted among a stratified random sample of 303 recently married couples (606 individuals). Of the eligible individuals, 70% (n = 380) participated. Of the respondents, 73% had a positive attitude toward a routine offer of preconceptional CF carrier screening, and 56% had the intention to participate in a screening program. A positive intention to have the test was associated with high perceived anticipation of regret, intended preconceptional behavior, high perceived pressure from experts, high perceived consequences of the test results, low perceived barriers, and low perceived negative consequences for family members. These results suggest that the offer of routine preconceptional CF carrier screening would lead to substantial acceptance among couples planning a pregnancy. Several variables related with intention were identified.     

Cystic fibrosis carrier population screening in the primary care setting.

To determine the receptivity of prenatal care providers and their patients to carrier testing for cystic fibrosis (CF), we offered free carrier screening, followed by genetic counseling of carriers, to all prenatal care providers in Rochester, NY, for all their female patients of reproductive age, pregnant or not. Of 124 prenatal care providers, only 37 elected to participate, but many of these offered screening only to pregnant women. The acceptance rate among pregnant women was approximately 57%. The most common reasons for accepting screening were to obtain reassurance (50.7%) and to avoid having a child with CF (27.8 %). The most common reasons for declining screening were not intending to terminate a pregnancy for CF (32.4%) and believing that the chance of having a CF child was very low (32.2%). Compared with decliners, acceptors were more likely to have no children, regarded having a child with CF as more serious, believed themselves more susceptible to having such a child, knew more about CF, would be more likely to terminate a pregnancy if the fetus were shown to have CF, and more strongly supported offering CF screening to women of reproductive age. Of 4,879 women on whom results were obtained, 124 were found to be carriers. Of these 124 carriers, the partners of 106 were tested. Of the five at-risk couples, four requested prenatal diagnosis and one requested neonatal diagnosis. No woman found to be a carrier whose partner tested negative requested prenatal diagnosis. Except for the imperfect knowledge of those testing negative, none of the adverse outcomes predicted for CF carrier testing in the general population were observed in this study.     

Cystic fibrosis heterozygote screening in 5,161 pregnant women.

A screening program for cystic fibrosis (CF) heterozygotes was conducted in a large HMO prenatal population, to evaluate the level of interest among eligible patients, the effectiveness of prescreening education, attitudes toward the screening process, psychological effects, and utilization of prenatal diagnosis and its outcomes. The heterozygote identification rate and frequency of specific CFTR mutations were also assessed. Identified carriers were offered genetic counseling and testing of male partners. Prenatal diagnosis was offered if both parents were identified as carriers. A total of 5,161 women underwent carrier testing; 947 others completed survey instruments only. The acceptance rate of screening was high (78%), and pretest education by videotape was generally effective. Adverse psychological effects were not reported. Participants generally found screening to be desirable and useful. Screening identified 142 female heterozygotes, 109 couples in which the male partner was not a carrier, and 7 high-risk couples. The incidence of R117H mutations was much higher than expected. The number of identified carriers was much lower in Hispanics than in Caucasians. We conclude that large-scale prenatal screening for CF heterozygotes in the absence of a family history of CF is an acceptable method for identifying couples at risk for affected fetuses. Sufficient pretest education can be accomplished efficiently, test insensitivity is well accepted, adverse psychological events are not observed, and general patient satisfaction is high.     

Linkage disequilibrium, cystic fibrosis, and genetic counseling.

Strong linkage disequilibrium occurs between the cystic fibrosis (CF) locus and polymorphisms detected with the DNA probes XV-2c and KM-19. In a North American population, 86% of CF chromosomes occur with a haplotype which occurs on only 14% of normal chromosomes. An individual homozygous for the highest-risk haplotype has an 81-fold greater probability of carrying a CF allele than does an individual homozygous for the lowest-risk haplotype. The linkage-disequilibrium data can be used for prenatal diagnosis and genetic counseling in CF families. The data are useful in 1-in-4-risk pregnancies when DNA is not available from the propositus and in counseling close relatives of CF families. Serious problems arise with some pregnancies which remain at intermediate risks after analysis, and families are left with difficult decisions. It is not clear that genetic testing for couples at less than 1-in-4 risk is cost-effective or standard care, but use of linkage-disequilibrium data will provide more accurate risk probabilities in a substantial proportion of cases if such testing is carried out. Our results emphasize the need for a specific biological or molecular carrier test. This experience in using linkage-disequilibrium and linkage data in combination for genetic counseling provides a model system for the diagnosis of other disorders.     

The place of prenatal diagnosis in genetic counseling (1982-1983)

34.2% of couples seen during the years 1982 and 1983 for genetic counselling had some kind of familial anamnesis such as affected partner or relative or children. They could have benefit from prenatal diagnosis who would have been accurate informative twice on three times. Indications methods and accuracy are studied in consideration to the reason of referring and the level of the risk. Genetic counselling and prenatal diagnosis appear as preventive means adapted to each consultant. Otherwise systematic ultrasonography allows a true prevention from which 17.6% of the couples having give birth to affected children could have benefit.     

Carrier screening for cystic fibrosis in a prenatal setting

Maternal prenatal cystic fibrosis (CF) screening was offered from September, 1997, to April, 1999, at the Ghent University Hospital, to couples undergoing prenatal diagnosis (amniocentesis) for reasons not related to CF. Fifteen minutes were devoted to explaining CF, CF screening, and the study protocol. The purpose was to assess the short- and long-term knowledge of CF, the attitude towards carrier screening, and carriership. A total of 314 couples entered the pilot study; 13 female CF carriers were identified. None of their partners carried an identifiable mutation. Our survey results show that information about CF and CF screening can be given effectively as part of antenatal care because most couples recalled important medical and genetic issues, valued the genetic test for CF, and seemed to cope well with the results. Risk estimates and actual numbers were more difficult to process and recall. From the small number of couples in which the woman alone was found to be a carrier, there was little or no evidence of marked distress.     

Activity of enzymes in amniotic fluid in prenatal diagnosis of cystic fibrosis

The activity of microvillar enzymes--gamma-glutamyltranspeptidase, aminopeptidase, general and intestinal forms of alkalyne phosphotases was studied in amniotic fluid (AF) of 33 women with 25% risk of cystic fibrosis (CF) (mucoviscidoses) in their progeny. The figures obtained in this group were compared with corresponding values of the same enzymes in 100 AF samples from normal pregnancies (negative control) and with 9 AF samples from women which were known to give birth to the children with CF (positive control). CF has been predicted in 5 cases, pregnancies were artificially terminated in 4 women. Biochemical CF prediction was proved by immunochemical assay of albumin contents in meconium of fetal ileum. One woman from the high risk group refused abortion and gave birth to a CF child. Among 26 cases of low CF prediction, 13 resulted in birth of a child without a sign of CF, one - in a child with clear-cut diagnosis of CF and 12 other pregnancies still proceed. The efficiency of complex biochemical, pathomorphological and molecular approaches for verification of intrauterine CF diagnosis in aborted fetuses as well as for detection of heterozygous carriers of CF gene and prenatal diagnosis of CF is discussed.     

Requests for prenatal diagnosis from parents of children with cystic fibrosis

The request for prenatal diagnosis of cystic fibrosis has been evaluated by an interview during a visit at a cystic fibrosis clinic among 32 couples whose one or several children are affected. Six couples resorted to the procedure between June 1984 and October 1985. In all the cases, in these families the only child (or children) alive was affected. The diagnosis of the disease in the first affected child reduces the number of children planned by the family. The significant use of the test, since its availability points to the existence of a real demand from the parents.     

Cystic fibrosis: typing 48 German families with linked DNA probes

Summary Two hundred and thirty five subjects from 48 German cystic fibrosis (CF) families were typed for restriction fragment length polymorphisms (RFLPs) detected by the probes pmet H, pmet D, and pJ 3.11, known to be tightly linked to the CF gene. Gene and haplotype frequencies suggest a linkage disequilibrium with the CF locus. The analysis of the predictive value of this typing in individual CF families indicates that the combined use of these probes provides a powerful diagnostic system both for carrier detection and prenatal diagnosis. In 33 out of 48 families carriers and non-carriers could be identified, and in 26 of these 33 families prenatal diagnosis could discriminate between affected and unaffected offspring.     

Carrier detection and prenatal diagnosis of cystic fibrosis using an intragenic TA-repeat polymorphism

Summary We have analysed the segregation of a TA-repeat polymorphism in intron 17b of the cystic fibrosis transmembrane conductance regulator gene responsible for cystic fibrosis (CF) in 23 French CF families non-informative for the F508 mutation (i.e. with at least one parent not carrying F508) or closely linked DNA markers. At least 13 different alleles ranging from 7 to 45 repeats were observed and the detected heterozygosity was 89%. Of the 23 families studied, 19 were fully informative for prenatal diagnosis or carrier detection, 3 were partially informative and one was not informative. In 6 families, prenatal diagnosis for CF or carrier detection in siblings of CF cases were performed using this polymorphism.     

Cystic fibrosis typing with DNA probes and screening for ΔF508 deletion in families from Southern France

Summary A sample of 235 individuals from 49 French cystic fibrosis (CF) families with at least one living affected child was typed with probes for restriction fragment length polymorphisms (RFLPs) known to be linked to the CF gene, and was screened for the ΔF508 mutation. Using a combination of six probes, 44 out of the 49 families were sufficiently informative to enable prenatal diagnosis or carrier determination. As in many other populations, linkage disequilibrium was found between the CF locus and the haplotype B (XV2c: allele 1; KM19: allele 2), which accounts for about 78% of CF chromosomes in our families. The ΔF508 deletion was present in 64.3% of CF chromosomes.     

Attitudes of deaf adults toward genetic testing for hereditary deafness.

Recent advances within molecular genetics to identify the genes for deafness mean that it is now possible for genetic-counseling services to offer genetic testing for deafness to certain families. The purpose of this study is to document the attitudes of deaf adults toward genetic testing for deafness. A structured, self-completion questionnaire was given to delegates at an international conference on the "Deaf Nation," held at the University of Central Lancashire in 1997. The conference was aimed at well-educated people, with an emphasis on Deaf culture issues. Eighty-seven deaf delegates from the United Kingdom returned completed questionnaires. The questionnaire had been designed to quantitatively assess attitudes toward genetics, interest in prenatal diagnosis (PND) for deafness, and preference for having deaf or hearing children. The results from this study provide evidence of a predominantly negative attitude toward genetics and its impact on deaf people, in a population for whom genetic-counseling services are relevant. Fifty-five percent of the sample thought that genetic testing would do more harm than good, 46% thought that its potential use devalued deaf people, and 49% were concerned about new discoveries in genetics. When asked about testing in pregnancy, 16% of participants said that they would consider having PND, and, of these, 29% said that they would prefer to have deaf children. Geneticists need to appreciate that some deaf persons may prefer to have deaf children and may consider the use of genetic technology to achieve this. Any genetic-counseling service set up for families with deafness can only be effective and appropriate if clinicians and counselors take into consideration the beliefs and values of the deaf community at large.     

Attitudes and knowledge about presymptomatic genetic testing among individuals at high risk for familial,early-onset Alzheimer's disease

The study was conducted in a large Cuban family with early-onset familial Alzheimer's disease (AD). Fifty-six first-degree relatives of familial cases with AD were interviewed concerning their clinical and genetic knowledge about AD and their attitudes toward the possible use of presymptomatic genetic testing of AD. The individuals had only limited knowledge about their personal risk of developing AD. All 56 family members would use presymptomatic testing to know their own risk of AD. Confronted with a hypothetical reproductive choice, 50% would choose not to have children if they themselves had the mutation. A positive prenatal test would lead 48.2% of the participants to have an abortion, and 19.7% would continue the pregnancy regardless of the positive test result.     

Cystic fibrosis: typing 89 German families with linked DNA probes

Summary Three hundred and ninety-two subjects from 89 German families were typed for restriction fragment length polymorphisms (RFLPs) detected by the probes pmetH, pmetD, pJ3.11, KM19, and XV2c known to be tightly linked to the cystic fibrosis (CF) gene. The analysis of the predictive value of this typing in individual CF families indicates that the combined use of these probes provides a powerful diagnostic system for both carrier detection and prenatal diagnosis. In 45 families the complete haplotype including all RFLPs was available. Of them 41 (91.1%) were fully informative and 4 were partly informative.     

Lack of interest by nonpregnant couples in population-based cystic fibrosis carrier screening.

We used signs and letters to offer free cystic fibrosis (CF) carrier screening to nonpregnant adults in stable relationships who visited numerous clinical and nonclinical sites in Nashville. A total of 179 individuals (<<1% of those eligible) elected to be tested. To understand this observation, we used questionnaires to assess individuals' attitudes about genetic testing in general and about CF carrier screening in particular (n=873). Participants expressed conflicting views about carrier screening. More than 90% of people thought that genetic testing should at least be available. Most respondents said that the views of their partners and physicians were important in their decision making, and most believed that these others favored genetic testing. Yet, more than two-thirds indicated that such factors as insurability, being "at risk," what they would need to learn, abortion, and religious beliefs were important in their decision making, opinions that mitigated against genetic testing. In particular, one-third feared that carriers would lose their health insurance, one-quarter said that they would have been more interested had they been able to provide DNA by buccal swab rather than by finger stick, and less than one-sixth believed that genetic testing was meddling in God's plan. In the face of both the low level of use of free CF carrier screening by nonpregnant couples when it was not offered in person by health-care professionals and the wide variety of concerns demonstrated, we believe that clinicians should not routinely offer carrier screening to nonpregnant individuals who do not have a family history of CF.     

Homogeneity of cystic fibrosis in Italy.

In 12 unrelated Italian cystic fibrosis (CF) families the frequencies of four DNA polymorphisms closely linked to the CF gene on chromosome 7 were quite similar to those reported for other population samples. Among the 23 affected children from the 12 families, only one recombinant occurred between the CF gene and the met locus, thus confirming the hypothesis of genetic homogeneity of CF previously suggested by the analysis of consanguineous marriages among 624 couples of CF parents. Chi-square test of association indicates a possible linkage disequilibrium between the CF gene and the DNA polymorphism that is most informative in our sample (pmetH TaqI).     

Attitudes of families affected by adrenoleukodystrophy toward prenatal diagnosis, presymptomatic and carrier testing, and newborn screening

Families affected by adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN) were surveyed to elicit attitudes toward prenatal, presymptomatic and carrier testing, and newborn screening in order to determine the level of support that these families have for current and future genetic testing protocols. Identifying attitudes toward genetic testing, including newborn screening, is especially important because of new data regarding therapeutic options and the possible addition of ALD to newborn screening regimens. The Kennedy Krieger Institute (KKI) database identified 327 prospective participants. Families that were willing to participate in the study received an anonymous questionnaire for completion. Frequencies were generated using SPSS software for Windows. Questionnaires were returned from 128 families for a response rate of 39%. Sons who were at risk for inheriting the ALD gene would be tested by 93% of respondents, and 89.3% would ideally have this testing performed prenatally or in the newborn period. Eighty-nine percent would test an at-risk daughter and 51.2% would ideally have this testing performed prenatally or shortly after birth. ALD newborn screening for males and females was supported by 90% of respondents. If newborn screening for ALD/AMN commences, or there is a new diagnosis of ALD, genetic professionals need to be prepared to have extensive conversations with families regarding the benefits and limitations of current therapeutic and genetic testing options.     

Cystic fibrosis typing with DNA probes: experience of a screening laboratory

Summary A sample of 125 individuals from 37 British cystic fibrosis (CF) families with at least one living affected child were typed with probes for restriction fragment length polymorphisms (RFLPs) known to be linked to the CF gene. These probes were MetD, MetH, pJ3.11 and 7C22. Using this combination of probes, 30 out of the 37 families were sufficiently informative to enable prenatal diagnosis of the disease. Linkage analysis has also proved to be useful in excluding CF in two cases where diagnosis of the disease was equivocal in the sibling of an affected child.     

A sense of autonomy is preserved under Chinese reproductive policies

China has had a one-child family policy since 1979 and a National Family Planning Law since 2002. This paper presents analysis of comments from members of the general public and experts in China on the question of reproductive autonomy. The Chinese concept of 'Yousheng' (healthy birth) is more appropriate than eugenics as an expression of Chinese social policy and public attitudes. The widespread support for healthy birth has policy implications. None of the persons interviewed said that they had ever used ultrasound to choose the gender of their child nor had an abortion for the reason of a fetus's gender. Despite the bad impression of abortion from their experience, most would abort a fetus with a genetic disease. Respondents in rural areas were less likely to use prenatal care, pointing to more important social problems in reproduction in China. The impressions given from the survey stands in contrast to the implications of the majority of Western papers on the Chinese situation, and indicate that people are generally satisfied with the ethical balance towards the societal needs over individual autonomy, but they still have a sense of reproductive autonomy. There needs to be further study into these issues with larger surveys and interview studies.