Perspectives in genetic screening. Principles and implications

Recent advances in genetic identification and characterization of a number or hereditary disorders have led to increased possibilities for genetic testing and screening. The context and methods of screening are important given that identification of otherwise healthy persons as being presymptomatic or at increased risk for genetic diseases may have serious consequences for their future lifestyle, employment, and insurability. This article examines general principles for genetic screening, including goals, delivery issues, and professional and lay responses to screening and counseling, and recommends areas in which social psychological research on screening is needed.

National policy development for the clinical application of genetic diagnostic technologies. Lessons from cystic fibrosis

In recognition of the earlier experiences with genetic diagnostic services and in anticipation of a greater potential for genetic testing for presymptomatic disease and disease susceptibility, this article provides an analysis of policy development for cystic fibrosis carrier screening. The deficiencies of relying on an extemporaneous model for health policy development are described. Preferably, an evidentiary model, based on the evaluation of clinical research and incorporating professional and public attention to underlying normative issues, should define the standard of care. Appropriate procedural mechanisms should be established at both state and federal levels to prevent the unnecessary confusion, expense, and personal or social harms likely to result from a completely unrestrained application of developing genetic technologies or continuing ad hoc responses to rapid increases in genetic diagnostic capabilities. A broadly constituted national advisory commission on the ethical, legal, and social implications of the Human Genome Project would provide an important locus for national decision making and may offer an efficient mechanism for implementing the evidentiary model, promoting public involvement at a time when social policy decisions must be made to restructure the health care system to be more sensitive to issues of access, allocation, and costs.

Attitudes toward direct predictive testing for the Huntington disease gene. Relevance for other adult-onset disorders. The Canadian Collaborative Group on Predictive Testing for Huntington Disease

OBJECTIVE

To assess attitudes toward, and projected utilization of, direct mutation testing by individuals at risk for Huntington disease (HD).

DESIGN

Prior to the cloning of the gene for HD, a questionnaire concerning the use of a definitive test was constructed and mailed to 354 participants in the Canadian Collaborative Study for HD. Completed questionnaires were received from 250 participants (response rate, 71%). Persons were asked to indicate whether they would participate in a new predictive test that was either 100% accurate (the definitive test, requiring blood only from the proband) or only 99% accurate.

RESULTS

Most (72%) of the persons who had previously received a result in a predictive testing program said they would request testing in either situation. Significantly more persons would request the definitive test than the 99% accurate test (72% vs 58%; P < .02). Respondents for whom testing was uninformative in the linkage test program or who had previously received an increased-risk result were more likely to indicate they would use the test than those who received a decreased-risk result or chose not to have the original test (P = .0003). Less than half (46%) of the participants who initially chose not to have the linkage test said they would return for the new direct test. The major factor that has limited acceptance of predictive testing for this group is the concern about receiving an increased-risk result in the absence of any therapy to alter progression of the disease.

CONCLUSIONS

A direct mutation test for HD will most readily be accepted by persons who wanted but could not previously receive a result in the linkage test program and those who previously received an increased-risk result. In the absence of therapy, the majority of persons who previously chose not to have predictive testing are unlikely to participate in a new test despite improved accuracy. This has implications for the expected demands for testing services for other adult-onset genetic disorders.

Antenatal cystic fibrosis carrier screening--whether, when and how?

Population screening for carriers of cystic fibrosis (CF) is now possible. Such screening may have both advantages and disadvantages and hence must be evaluated before it becomes routine practice. As the potential benefits of screening are wide and the drawbacks may include psychological effects, a combination of approaches is needed to assess screening thoroughly instead of only counting numbers of terminations or carrier tests. We describe the issues concerned and our methodology for a rigorous evaluation of population antenatal carrier screening for cystic fibrosis.

Cystic fibrosis carrier screening: knowledge and attitudes of prenatal care providers

We are conducting a trial of population carrier screening for cystic fibrosis (CF), targeting pregnant and nonpregnant patients of prenatal care providers. We first enlisted providers by presenting a description of the trial to the obstetrical staffs of the five Rochester, New York, hospitals having delivery services. Of the 124 prenatal care providers (111 obstetricians and 13 family practitioners) with delivery privileges at the five hospitals, only 81 (65%) attended one of our presentations. Providers who attended lacked knowledge about CF screening and counseling and expressed divergent attitudes about prenatal diagnosis for carrier women having test-negative partners. Of the 79 providers completing an attitude questionnaire, 68 (86%) were willing to offer carrier screening to all their patients if educational materials, testing, and counseling were all provided without charge. After visiting participating physicians' offices to orient their staff, we reached two additional conclusions. First, in considering whether to offer CF carrier screening to their patients, prenatal care providers are less concerned about imperfect test sensitivity, false reassurance of those testing negative, or discrimination against those testing positive than about time required to answer patients' questions if they screen and about legal liability if they do not. Second, some providers are more resistant to offering screening to nonpregnant patients than to pregnant patients, not because they believe that the timing is less appropriate, but because nonpregnant patients do not routinely receive an advance mailing, have phlebotomy, or return for follow-up. Our experience raises concerns about the willingness and capability of prenatal care providers to translate advances in molecular medicine into prenatal screening services.

Prenatal cystic fibrosis carrier screening: factors in a woman's decision to decline testing

Among 2207 women eligible to be screened for cystic fibrosis (CF) carrier status during pregnancy, 325 (15 per cent) declined to be tested. Of these, 260 (80 per cent) answered a questionnaire soliciting their reasons for not participating. The main factor was opposition to termination of pregnancy, with 43 per cent being against termination for any reason and another 11 per cent against termination of a CF fetus. Other reasons given were partner's disapproval or non-participation (10 per cent), perceived risk of a CF child being low (7 per cent), the error rate of the test (6 per cent), and the generation of unacceptable levels of anxiety (5 per cent). Eleven women (4 per cent) said that they did not wish to be tested during pregnancy, but only six of these would have accepted screening at another time.

Diagnosis of Huntington disease: a model for the stages of psychological response based on experience of a predictive testing program

Persons diagnosed as affected with Huntington's disease (HD) may have similar stages of psychological response to the clinical presentation of the illness. Here we describe a model of these stages of response based on our experience during a predictive testing program for HD. During the Warning Stage, asymptomatic persons are aware of their risk status for HD and develop defenses which favor adaptation to their genetic risk. In response to the initial signs and symptoms of HD (the Incipient Stage) unconscious working through of this realization occurs while it is still kept out of conscious awareness. When symptoms become obvious such that recognition of disease onset is inevitable (Breakthrough Stage) the possibility of the diagnosis of HD is assimilated. After the delivery of the diagnosis during the Adjustment Stage, short- and long-term adaptive responses to living with HD occur. Recognition of the stage of psychological response of a patient who presents with HD is important prior to delivering a clinical diagnosis. In a significant minority of cases, the psychological readiness lags behind the clinical symptomatology and premature presentation of a diagnosis may result in significant untoward adverse events. Understanding of the stages of response may provide a framework for evaluating the psychological state of the person with HD and determining their readiness to receiving the diagnosis. This model may have relevance to the psychological responses of patients to the diagnosis of other late onset autosomal dominant disorders.

On choosing a baby's sex: what the future generation thinks, a preliminary survey

The new biomedical techniques of reproduction, such as predetermination of a baby's sex, are gradually being initiated into formal practice in some countries such as Britain. This paper surveyed the attitudes of 60 academic and 60 nonacademic men and women between 18 and 20 years on whether they supported the idea of choosing a baby's sex. More than 75% of all participants rejected the idea of choosing a baby's sex, whilst only 20% agreed with the latter issue and a negligible number (4%) offered no opinion. Neither sex differences nor differences between academic/nonacademic population were significant. The results are discussed in relation to recent work on differences in attitudes between genders in academic and nonacademic settings.

On attitudes and appreciation 6 months after predictive DNA testing for Huntington disease in the Dutch program

We have studied the 6-month follow-up attitudes of 63 individuals, after predictive testing for Huntington disease (HD). Reducing uncertainty (81%) and family planning (60%) were the major reasons for taking the test. Twenty-four individuals were diagnosed as having an increased risk (+/- 98%), and 39 a decreased risk (+/- 2%). Among those with an increased risk, denial or minimization of the ultimate impact of the increased risk result was observed. Most of them (84%) rated their current life situation, at the very least, as being good. Twenty-one percent of individuals with an increased risk who originally planned to have a family, decided to refrain from having children. Sixty percent of those with increased risk who still wished to have children, would choose to have prenatal testing. In most individuals with increased risk, the test result did not increase the previously expected control over their own future. Half of the partners of persons with increased risk acknowledged the burden of the future disease. Half had no one in whom they could confide. They showed loyalty to the denial and avoidance reactions of their spouses. Half of the individuals with decreased risk denied the impact of the result, as reflected by absence of relief, and emotional numbness. A third of persons with decreased risk experienced involvement with problems of affected relatives. We found that 20% of all participants were discontented with the support given by their general practitioner, who is normally regarded as being the most significant professional for aftercare. Our findings suggest that the perpetuation

Genetic risk: women's understanding of carrier risks in Duchenne muscular dystrophy

This paper reports a study of 48 women (16 mothers and 32 daughters representing 28 families) who had lived with Duchenne muscular dystrophy (DMD) in their family. It looks at the way the women talked about their carrier risks during the course of an unstructured interview. It points to a significant difference between lay and health professionals' perspectives, in particular the thresholds they used to distinguish between high and low risk. A number of women, when quoting their risk in a mathematical form, confused their reproductive risks with their carrier risk, another indication of differential perceptions between the women and health professionals. There was evidence that several of the women did not retain their risk in a mathematical form but had translated it into a descriptive category which resolved their risk into greater certainty.

Perception of predictive testing for Huntington's disease by young women: preferring uncertainty to certainty?

Opinions on the implications of predictive testing for Huntington's disease were evaluated in a group of 169 women (aged 21-35 years) with interest in psychosocial issues, but with no special pre-existing knowledge or training in genetics. Predictive testing for Huntington's disease (HD) is considered to be a test case for predictive testing for other late onset diseases, monogenic as well as multifactorial disorders. In the hypothetical situation of having a 50% risk for developing HD, about half of the group expressed interest in a predictive test. As to the question of giving results of predictive tests to third parties, the group would be very reluctant to inform the employer or the insurer, but not their own family. Prenatal testing for late onset diseases was considered acceptable by half of the women; only one quarter of the total group would terminate a pregnancy of a child that might develop a late onset disease. The assessment of attitudes towards predictive testing was carried out within the context of a global evaluation of perceived advantages and disadvantages of genetic counselling. The attitudes towards predictive testing were systematically associated with perceiving 'having more certainty about the future' as an advantage of genetic counselling and with rejecting 'knowing everything in advance' as a disadvantage.

What young people think and do when the option for cystic fibrosis carrier testing is available

We report findings in phase II of a pilot study of cystic fibrosis (CF) carrier screening/testing by mutation analysis. Phase I has been reported elsewhere. Eligible participants in phase II (n = 815) were students (15 to 17 years of age) in public high schools. An educational component (exchange of information and discussion about common genetic disorders including CF) preceded, by one week or more, voluntary participation in the screening component which required a blood sample. The uptake rate for screening was 42%. Nine carriers (2pq = 0.0260) were identified, all with the delta F508 mutation; students were also tested for G551D, G542X, W1282X, and -549-mutations, but no carriers of these alleles were found. Carriers had positive views of the education and testing experiences. Persons identified as 'non-carriers' were also surveyed (n = 135, response rate 41%). As in phase I, the majority (83%) again understood that a negative DNA test had not excluded them from possible carrier status. Students who participated in the informational component but were not screened served here as controls in the follow up survey (n = 208, response rate 53%). Their views were similar to those of the screened non-carriers, and similar also to those held by students, adults, pregnant women, couples, and CF relatives in other communities.

Prenatal screening for cystic fibrosis: psychological effects on carriers and their partners

This study aimed to assess the psychological impact of screening for cystic fibrosis (CF) carrier status in a population of pregnant women. A cohort of 1798 women, who accepted the offer of testing before 18 weeks of pregnancy, filled in a self administered questionnaire seeking information on their perceived risk of carrier status and their emotional response, as well as a general health questionnaire (GHQ). Sixty-four women identified as CF carriers had partners who received a negative test result. This group and their partners were assessed, together with selected controls, on four further occasions: (1) on receiving the carrier's positive test result; (2) on receiving the partner's negative test result; (3) six weeks later; (4) six weeks after delivery. The instruments used were the GHQ and the Symptom Rating Test (SRT). When compared to control subjects, carriers showed a significant increase in generalised psychological disturbance which could be attributed specifically to symptoms of anxiety and depression during the period (average four days) that they awaited their partner's test result. On receiving a partner's negative test result, the carriers returned to control levels and maintained this equilibrium. Although there was no significant difference in generalised psychological disturbance between partners and their selected controls, partners did become significantly more anxious and manifested feelings of inadequacy while awaiting their own test result. Both male partners and male control subjects were more likely to become anxious if their partner was distressed.

Five year study of prenatal testing for Huntington's disease: demand, attitudes, and psychological assessment

Adult predictive and prenatal testing programmes for Huntington's disease (HD) in Canada have been available since 1986. However, the demand for prenatal testing and the reasons why some people choose not to have the prenatal test for this late onset disorder have not been well documented. In addition, the knowledge and attitudes of adult predictive testing candidates and their partners about prenatal testing are not well known nor are the psychological effects of prenatal testing well understood. As of September 1991, 425 subjects had entered the Canadian Collaborative Study of Predictive Testing and, of these, 47 subjects or their partners had become pregnant. Of this group, 14 (30%) couples requested prenatal testing, 24 (51%) couples did not want prenatal testing, and nine (19%) at risk subjects had already received a decreased risk through adult predictive testing and, therefore, were not eligible for the prenatal test. Of the 14 couples who initially requested prenatal testing, seven withdrew. Thus, demand for the prenatal test by eligible candidates was 7/38 or 18%, which is much lower than the 32 to 65% expected based on early survey data. The most frequently cited reason for declining prenatal testing was the hope that a cure would be found in time for their children. While the majority of adult predictive testing candidates (71%) in our study had accurate information about definitive prenatal testing, many (63%) did not have a correct understanding of exclusion prenatal testing. Although no serious adverse events such as suicide planning or admission to psychiatric hospital have occurred, a particular need for careful counselling was identified for those at risk candidates and their partners who have one prenatal test and feel compelled to use the test again in future pregnancies. Even though prenatal testing for HD is not requested as often originally expected, it still remains a desired option for some at risk persons and their partners.

Grief and mid-trimester fetal loss

Fetal loss through miscarriage or termination of pregnancy for genetic reasons often provokes the grief of bereavement. This is not fully understood, and the extent of the distress is often underestimated by professionals and family alike. We have examined elements of the normal bereavement process and have found that they may occur in specific and accentuated forms in mid-trimester fetal loss. We discuss our findings in the light of the attachment theory--a psychodynamic model for understanding grief reactions.

Interest in genetic testing for colon cancer susceptibility: cognitive and emotional correlates

BACKGROUND

Recent advances in human genetics have led to the identification of markers for cancer susceptibility. Nevertheless, little is known about the public's interest in clinical genetic testing for cancer-related markers.

METHODS

A random-digit-dial telephone survey of 401 adult residents of Utah was conducted during the summer of 1990. Respondents were randomized to one of three question frames and asked about their interest in a potential genetic test for colon cancer susceptibility. They were also asked to rate their risk for colon cancer, how often they worried about contracting any type of cancer, and how often they felt worried and nervous during the past year (trait anxiety).

RESULTS

Eighty-three percent of respondents expressed interest in genetic testing. Level of interest was most strongly correlated with perceived risk for colon cancer (r = 0.21, P < 0.001). Responses were not affected by the use of different question frames.

CONCLUSIONS

These results show a high level of public interest in genetic testing for colon cancer susceptibility. The data also suggest that anxiety does not undermine interest, but future research must determine whether this relationship is limited to hypothetical judgments such as those studied here.

Attitudes of Dutch general practitioners towards presymptomatic DNA-testing for Huntington disease

The attitudes of 1020 Dutch GP's towards presymptomatic and prenatal testing for Huntington disease (HD) were studied by means of a postal questionnaire. The questionnaire contained questions about: approval of presymptomatic DNA-testing, informing individuals at-risk who do not request predictive testing, referral to a clinical genetics center, and opinions about different strategies of informing and supporting individuals at-risk. The response rate was 62%. More than two-thirds of the GP's considered post-test counselling and support as their responsibility. Twenty-six per cent were of the opinion that the test results should be disclosed by the GP. Fifty-nine per cent of GP's who had an individual at-risk in their practice were familiar with the test. The attitudes of GP's towards giving support and giving test results were independent of familiarity with the test and the incidence of HD-patients or at-risk individuals in the practice. Although GP's were willing to play an important role in presymptomatic DNA-testing procedures, there is a risk that they might underestimate the difficulties in communicating genetic information and the psychosocial effects of DNA-testing. Hence, we favor the premise that extensive pretest counselling and test disclosure should remain the prime responsibility of the clinical geneticist. Increasing involvement of GP's should, however, be encouraged and combined with appropriate postgraduate education about predictive DNA-testing in general.

Geneticists approach ethics: an international survey

Fletcher, Berg and Tranøy (1985) proposed that medical geneticists around the world would benefit from collective reflection on their preferred approaches to the most frequent of the difficult moral choices in practical genetics. In 1985-86, Wertz & Fletcher undertook a survey of geneticists' views in 19 nations. Results were widely disseminated. In this paper, the authors describe a new survey that they are conducting in 37 nations.

The psychological consequences of predictive testing for Huntington's disease. Canadian Collaborative Study of Predictive Testing

BACKGROUND

Advances in molecular genetics have led to the development of tests that can predict the risk of inheriting the genes for several adult-onset diseases. However, the psychological consequences of such testing are not well understood.

METHODS

The 135 participants in the Canadian program of genetic testing to predict the risk of Huntington's disease were followed prospectively in three groups according to their test results: the increased-risk group (37 participants), the decreased-risk group (58 participants), and the group with no change in risk (the no-change group) (40 participants). All the participants received counseling before and after testing. Standard measures of psychological distress (the General Severity Index of the Symptom Check List 90-R), depression (the Beck Depression Inventory), and well-being (the General Well-Being Scale) were administered before genetic testing and again at intervals of 7 to 10 days, 6 months, and 12 months after the participants received their test results.

RESULTS

At each follow-up assessment, the decreased-risk group had lower scores for distress than before testing (P < 0.001). The increased-risk group showed no significant change from base line on any follow-up measure, but over the year of study there were small linear declines (P < 0.023) for distress and depression. The no-change group had scores lower than at base line on the index of general well-being at each follow-up (P < or = 0.045). At the 12-month follow-up, both the increased-risk group and the decreased-risk group had lower scores for depression and higher scores for well-being than the no-change group (P < or = 0.049).

CONCLUSIONS

Predictive testing for Huntington's disease has potential benefits for the psychological health of persons who receive results that indicate either an increase or a decrease in the risk of inheriting the gene for the disease.