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

Providing recurrence risk counselling for parents after diagnosis of a serious genetic condition caused by an apparently de novo mutation in their child: a qualitative investigation of the PREGCARE strategy with UK clinical genetics practitioners

BACKGROUND

Diagnosis of a child with a genetic condition leads to parents asking whether there is a risk the condition could occur again with future pregnancies. If the cause is identified as an apparent de novo mutation (DNM), couples are currently given a generic, population average, recurrence risk of ~1%-2%, depending on the condition. Although DNMs usually arise as one-off events, they can also originate through the process of mosaicism in either parent; in this instance, the DNM is present in multiple germ cells and the actual recurrence risk could theoretically be as high as 50%.

METHODS

Our qualitative interview study examined the views and reflections on current practice provided by UK practitioners working in clinical genetics (n=20) regarding the potential impact of PREcision Genetic Counselling And REproduction (PREGCARE)-a new preconception personalised recurrence risk assessment strategy.

RESULTS

Those interviewed regarded PREGCARE as a very useful addition to risk management, especially for cases where it revised the risk downwards or clarified that a couple's personalised recurrence risk meets National Health Service thresholds for non-invasive prenatal testing, otherwise inaccessible based on the generic DNM recurrence risk.

CONCLUSION

Participants said it could release some couples requiring reassurance from undergoing unnecessary invasive testing in future pregnancies. However, they regarded mosaicism and PREGCARE as complex concepts to communicate, requiring further training and additional appointment time for pre-test genetic counselling to prepare couples for all the possible outcomes of a personalised risk assessment, including potentially identifying the parental origin of the DNM, and to ensure informed consent.

"You will ask me: which am I?": the clinical practice of Chagas as a latent risk

Drawing on observation-based ethnography, interviews of health personnel and document review, this article describes and examines how, in clinical handling of Chagas disease, infection is treated as latent risk. It suggests that how this risk is managed has enabled a clinical practice to be conducted among people classified as at the indeterminate stage, by adding a dimension of possibility (Is it going to happen?) and potentiality (When and where?). This allows measures to be taken, including administration of medication or permanent monitoring. The reification of latent risk as a phenomenon that is manageable through a process of medicalisation engages, in turn, with other conceptions and specific experiences of risk among the affected groups. Framing the clinical practices deployed to address this risk as objects of study is a first step towards being able to describe and include them concretely in health system organisation.

Communicating Risk Information in Genetic Counseling: An Observational Study

This study investigates risk communication within genetic counselling. Transcripts of 115 U.K. genetic consultations were reliably coded into form of risk expression used, whether the patient responded with understanding and agreement or showed signs of misunderstanding or disagreement, or did not respond at all, and whether clinicians assessed patient comprehension. Of the 492 risk expressions used, 53% were words and 47% were numbers (32% probabilities and 15% percentages). There was no association between form of risk expression and response. Clinicians assessed comprehension on only 25% of occasions, less often following the use of words than numbers, and on only 9% of occasions when there was no response to their risk communication. Because patients did not respond to 43% of risk communications, there is a concern that patients may make decisions without understanding the risks involved.

Understanding Life's Lottery

This article reviews studies of risk awareness of carriers of genetic disorders and individuals who attend genetic counselling. It focuses upon investigations of recall of risk estimates following counselling. Six factors are discussed which may influence individuals' recall of genetic risk estimates. These include: mode of genetic transmission, counsellees' reproductive behaviour or intentions, time delay between counselling and data collection, prior familiarity with the disorder, subjective perceptions of risk, and the way that risk information is presented during counselling. It is argued that using counsellees' recall of genetic risk estimates as a measure of the effectiveness of counselling is problematic, both at a methodological and conceptual level. It is suggested that assessments of the effectiveness of genetic counselling must involve an approach which conceptualizes counselling as a dynamic process in which both counsellee and counsellor have active roles to play.

Preconception counseling: do patients learn about genetics from their obstetrician gynecologists?

PURPOSE

The purpose of this observational survey study is to assess genetic knowledge in reproductive-aged women and to determine the role played by their obstetricians in their education.

METHODS

A 31-item survey was distributed via an internet survey service to women between the ages of 18 and 45. The survey included subject demographics, a query regarding the source of subjects' knowledge of genetics, and 6 question genetics quiz with 3 fundamental questions and 3 advanced questions. Subjects were divided into parous and nulliparous groups, and responses were compared using student's t-test for continuous variables and chi square for proportions.

RESULTS

Participants included 207 parous and 221 nulliparous women. There were no differences in demographic characteristics including age and education. Parous women scored significantly higher than nulliparous women on the fundamental genetics quiz (71 vs 61 %, p = 0.03). This difference remained but was no longer significant when the 3 advanced questions were included (48 vs 42 %). Only 39 % of parous and 8 % of nulliparous subjects listed their physician as one of their main sources of genetic information. 78 % of all subjects stated that they would prefer to receive genetic information from their physicians over other sources.

CONCLUSIONS

Recently parous women scored higher on a genetics assessment quiz than did their nulliparous counterparts, but the majority did not cite their obstetrician gynecologists as a main source of information. As genetic counseling and testing are becoming increasingly important aspects of obstetrical care, obstetricians should play a more substantial role in educating their patients.

Making sense of risk diagnosis in case of prenatal and reproductive genetic counselling for neuromuscular diseases

This study explored the processes of significance about the risk communication in prenatal/preconception setting within 1 month to the end of genetic counselling intervention. Participants were all attending a programme of Cardiomyology and Medical Genetics in Naples, Italy, for the first time. Transcripts of 18 semi-structured interviews were analysed using interpretative phenomenological analysis. Themes arising included the following: the familiar outcomes of genetic counselling, the risk representation and the impacts on decision-making. The findings suggest the significance of the experience of genetic risk and the implications for the support of individuals and their family after the conclusion of the genetic counselling intervention.

How risk is perceived, constructed and interpreted by clients in clinical genetics, and the effects on decision making: systematic review

As an individual's understanding of their genetic risk may influence risk management decisions, it is important to understand the ways in which risk is constructed and interpreted. We systematically reviewed the literature, undertaking a narrative synthesis of 59 studies presenting data on the ways in which individuals perceive, construct and interpret their risk, and the subsequent effects. While most studies assessed perceived risk quantitatively, the combined evidence suggests individuals find risk difficult to accurately quantify, with a tendency to overestimate. Rather than being a stand-alone concept, risk is something lived and experienced and the process of constructing risk is complex and influenced by many factors. While evidence of the effects of perceived risk is limited and inconsistent, there is some evidence to suggest high risk estimations may adversely affect health and lead to inappropriate uptake of medical surveillance and preventative measures by some individuals. A more focused approach to research is needed with greater exploration of the ways in which risk is constructed, along with the development of stronger theoretical models, to facilitate effective and patient-centered counseling strategies.

Communicating about haemophilia within the family: the importance of context and of experience

This study examines communication within families affected by haemophilia, focusing especially on communication about carrier status. A qualitative study using semi-structured interviews with family members in the UK revealed recurrent patterns in communication strategies and styles. Participants drew a marked contrast between the nature of communication within the clinic and within the home. In families, it is notable that communication usually occurs within the context of concrete experience of the condition. Noticeable differences existed in families with obligate carriers when compared with families with non-obligate carrier daughters. In families with affected sons, daughters may have more experience of haemophilia and consequently more understanding of their possible carrier status than in families with an affected father. Families also typically make value judgements and comments on coping strategies when they communicate about the condition. Readiness to receive information is very variable, and depends upon factors such as personality and life stage. Information may seem to be successfully communicated but the recipient may sometimes actually comprehend much less, only understanding more fully later or when the information becomes directly relevant to them. Periodic checking of understanding of different family members, and the provision of written information, may be helpful.

How does the mode of inheritance of a genetic condition influence families? A study of guilt, blame, stigma, and understanding of inheritance and reproductive risks in families with X-linked and autosomal recessive diseases

PURPOSE

While the mode of inheritance of a genetic condition has long been considered to have not only medical, but also psychosocial consequences for families, this supposition has never been tested.

METHODS

We surveyed 112 members of 51 families (59% response) with chronic granulomatous disease to determine the influence of mode of inheritance on parents', siblings', and patients' (1) knowledge of inheritance and reproductive risk; (2) concern about risk to future family-members; (3) feelings of guilt and blame; and (4) feelings of stigmatization. Ninety-six members of 51 families (49% response) with Duchenne/Becker muscular dystrophy and spinal muscular atrophy types II/III were also studied.

RESULTS

X-linked families had better understanding of inheritance (P < 0.001) and reproductive risks (P < 0.01). X-linked mothers worried more about risks to future generations; other autosomal-recessive family members were as worried. X-linked mothers were more likely to feel guilty (P < 0.01) and blame themselves (P < 0.001). X-linked fathers blamed their child's mother (P < 0.05) and X-linked mothers felt more blamed by the father (P < 0.01). X-linked family-members were more likely to consider being a carrier stigmatizing (P < 0.05).

CONCLUSION

When providing genetic counseling, attention should be given to guilt and blame in X-linked families and understanding reproductive risks in autosomal recessive families.

Service provision of complex mutation analysis: a technical and economic appraisal using dystrophin point mutation analysis as an example

Duchenne muscular dystrophy (DMD) results from mutations in the dystrophin gene. One-third of cases arise from point mutations, which are heterogeneous and difficult to detect. The aims of this study of dystrophin point mutation analysis were to assess its technical feasibility in a routine diagnostic laboratory, and to estimate its costs and clinical benefits. The methods used were a laboratory based study using reverse transcription-polymerase chain reaction (RT-PCR) and a protein truncation test, and a mathematical model to estimate costs and clinical benefits. None of the cases analyzed had an identifiable dystrophin deletion or duplication. They were 12 males affected with DMD and two obligate female carriers; two female carriers of known dystrophin point mutations were also analyzed. Point mutations were detected in six out of 12 males, but in none of the female carriers. Assuming a sensitivity of 50% the model predicts significant clinical benefits of point mutation analysis over linkage analysis, including a reduction in the number of prenatal diagnoses (by 0.77 per family), terminations of pregnancy (by 0.18 per family), and terminations of unaffected fetuses (by 0.16 per family). The mean cost of point mutation analysis to prevent the termination of an unaffected fetus is 6220 US dollars.

Research directions in genetic counselling: a review of the literature

There is a growing body of literature considering genetic counselling services in a variety of clinical settings. This literature encompasses both predictive and diagnostic testing, from the viewpoints of service providers and recipients. It also embraces a wide range of conceptions of the nature and goals of genetic counselling. However, research in this area has been criticised for a focus on outcome rather than process, and it has been suggested that this focus limits its practical use. The purpose of this review is twofold: (1) to describe the varying concepts of counselling which appear to be utilised in published work and (2) to discuss the possible applications of this work to practice.

Carrier testing of children for two X-linked diseases: A retrospective study of comprehension of the test results and social and psychological significance of the testing

OBJECTIVE

To evaluate long-term consequences of genetic carrier testing performed in childhood in terms of awareness and comprehension of the test result, and the social and psychological significance of such testing.

STUDY DESIGN

The families of 66 young females who had been tested for carriership during childhood between 1984 and 1988 were approached. Of the 66 families, 23 young females in families affected by Duchenne muscular dystrophy (DMD), 23 young females in families affected by hemophilia A (HA), and their mothers participated in our study. We used a questionnaire including multiple-choice and open-ended questions.

RESULTS

Of the young female participants tested in the families affected by DMD or HA, 65% knew their test results. Only 65% of DMD mothers and 78% of HA mothers remembered correctly the test results of their daughters. The majority (83%) of the young females tested sought no genetic counseling when reaching adulthood. The reason for this was not determined. Most (78%) reported that the test result had not influenced their lives, whereas some felt relieved to know they had not been carriers. Talking about hereditary disease in the family and between friends was open, and results of the carrier test had usually been told to friends.

CONCLUSION

Carrier testing was in most cases correctly understood and the matter openly discussed. Our results do not suggest that testing in childhood had caused serious harm to the young individuals tested. On the other hand, we found no obvious benefits from this early testing.

Understanding probabilistic risk in predisposition genetic testing for Alzheimer disease

The utility of genetic testing in preventing the onset of conditions such as Alzheimer disease (AD) depends upon categorizing individuals based on their "risk" of illness. Although no strategies to prevent the occurrence of AD have been proven effective, the promise of the new molecular medicine is based on the assumption that those "at risk" can be identified, counseled about their likelihood of developing a disease, and prescribed specific preventive interventions. We suggest that this paradigm of disease prevention through risk stratification has limitations that have not been fully explored. Within the fields of cognitive and health psychology, research has addressed how individuals understand the numeric presentation of uncertain future events; this research often focuses on the "perceptual pathology" of lay people. The uncertainty inherent in the risk estimates themselves is rarely considered, nor has research addressed how those risk estimates are created. There has been limited work to date focused on genetic risk assessment, and little is known about how individual might understand the meaning or consequences of being at genetic risk for AD. An emerging social science critique of concepts of risk in genetic medicine offers a broader perspective, examining the process of producing scientific risk estimates as well as the response of individual patients, such as the experience of embodied risk that is central to genetic testing. Making fully informed choices about genetic testing for AD may prove more difficult than our current model of ethical practice suggests.

Perceived personal control (PPC): a new concept in measuring outcome of genetic counseling

Many researchers have tried to establish criteria for the evaluation of genetic counseling and the assessment of its success. Most studies focused on counseling outcomes mainly educational and reproductive variables. In the present study we introduced the concept of "perceived personal control" (PPC), which captures a wider and more meaningful range of effects of genetic counseling. It was found to be central to coping with health threats and to adapting to a broad spectrum of health problems. This study investigated 154 counseling cases. Counselees were requested to complete pre- and post-counseling questionnaires consisting of a knowledge test, measures of PPC, expectations/evaluations of counseling, and satisfaction with the procedure. Comparisons of mean PPC scores before and after counseling showed significant increases. Higher post-counseling PPC was found among counselees who had been given a definite diagnosis, a specific recurrence risk, and been offered prenatal diagnosis. Post-counseling PPC also correlated with knowledge, satisfaction, counseling evaluations, and expectation fulfillment. The findings suggest that PPC is a valid measure for the evaluation of genetic counseling outcomes. The psychometrically reliable scales developed in this study can become helpful tools for assessing genetic counseling both in research and in clinical practice, helping the counselor evaluate the counseling session and focus on the counselees' needs.

Embodied risk: my body, myself?

Risk has become a dominant way to interpret who gets sick and why. A distinction has been drawn between two categories of risk: those arising from the environment, and those resulting from an individual's lifestyle. We identify a third category that might be called corporeal or embodied risk which has received little scholarly attention. Embodied risks are so called because they are located in the body of the person said to be "at risk". Environmental risks are due to something that happens to a person; lifestyle risks occur because of something a person does or does not do, while embodied risks say something about who the person is. To investigate how people experience health risks--especially risks identified as characteristics of their bodies--we conducted detailed interviews with 29 women who were told they had an abnormal Pap smear. All health risks pose problems for people who are diagnosed as "at risk": They must translate probabilistic statements about populations into terms that have personal meaning; they must cope with uncertainty; they must consider what it means to be in danger of developing an illness even though most have no symptoms; and they must mobilise appropriate surveillance and perhaps risk reduction. However, limiting attention to environmental and lifestyle risk (and the distinction between them) neglects the additional challenges posed by corporeal risks: the simultaneous presence of disease now and the possibility of more consequential disease in the future; the necessity to submit to ongoing medical surveillance; a tendency to exacerbate the cartesian split between body and self; and the absence of medical or popular discourses through which to interpret and respond to embodied risk. We call upon medicine and public health practitioners to work together with people who are at risk to formulate languages and approaches that can reflect both scientific accuracy (as it is currently understood), and the needs of people to integrate health threats into their daily personal lives.

Carrier screening for cystic fibrosis in primary care: evaluation of a project in South Wales. The South Wales Cystic Fibrosis Carrier Screening Research Team

Population carrier screening for cystic fibrosis (CF) was offered to all patients aged 16-45 in one general practice in South Wales, excluding those in couples with a current pregnancy. Out of 1553 patients in this group, 481 subjects were tested, giving an overall uptake rate of more than 30%. The rate of uptake varied with the mode of invitation. Twenty-six carriers were identified, giving a prevalence of identified carriers of 5.4% (1 in 18.5) for those with no family history of CF. A further 18 carriers were identified by cascade testing of these 26. We describe the practical difficulties encountered in setting up this programme in primary care in South Wales. Questionnaires were administered or distributed to all subjects before and after testing. The response rate for the pre-test questionnaire was 95%, and 40-50% for the post-test questionnaires. These showed that, at 3 months post-test, 1 in 4 screen-negative subjects did not appreciate that they had a residual risk of being a carrier. At the same time, 15% of this group thought that there was a 1 in 4 chance of a child being affected if one parent was screen-positive (carried an identified mutation) and the other was screen-negative, and 40% thought there was no risk. Anxiety in relation to testing did not appear to be a major problem, although individual patterns of response to carrier status varied widely and more sensitive indicators of psychosocial impact of genetic tests are required. A pilot study of couple screening showed that this approach is unlikely to be useful in primary care, although we did not assess couple testing during pregnancy. For any programme of CF carrier screening to be established in primary care, it will be necessary to involve the primary care team from the earliest planning stage, so that the opportunity costs, training needs and other costs of the programme can be fully resourced.

Attitudes towards bipolar disorder and predictive genetic testing among patients and providers

Attitudes about bipolar disorder (manic depressive disorder) and genetic testing were investigated. Three groups of subjects were surveyed including members of a manic depressive support group, medical students, and psychiatry residents. The questionnaire was intended to elicit impressions and attitudes about bipolar disorder (BP) from mental health consumers and health care providers with varying levels of personal and professional familiarity with the disorder. Attitudes towards prenatal testing and pregnancy termination were also assessed. The intention hypothetically to terminate a pregnancy was influenced by the likelihood of developing BP a well as the projected course and severity of illness. Nearly half of the total sample would terminate pregnancy if the fetus were definitely to develop an unspecified form of bipolar disorder. Presumed severity of illness was also found to be a modifying factor in the decision, with a low percentage of subjects electing to terminate for a mild course of bipolar disorder and a majority opting for termination in the case of an extremely severe presentation. Support group members were the least likely to terminate a hypothetical pregnancy in the case of a positive prenatal test and were the most likely to desire childhood testing in the absence of preventive or treatment options. The possible implications of these findings, as well as avenues of future research, are discussed.