The effects of genetic counselling in Duchenne muscular dystrophy

Experiences of Women Who Have Had Carrier Testing for Duchenne Muscular Dystrophy and Becker Muscular Dystrophy During Adolescence

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive degenerative muscular conditions. Carrier testing is available to at-risk females. Though carrier testing is often offered to adolescent females, it raises ethical issues related to autonomy. This study aimed to address the impact of DMD/BMD carrier testing during adolescence, to elucidate what motivates adolescents to seek testing, and to assess the carrier testing experience. Retrospective semi-structured telephone interviews were conducted with 12 women out of 28 initially contacted. Data were coded using thematic analysis. For most (8/12) participants, discovering their carrier status during adolescence appeared to have helped alleviate uncertainty. The majority (9/12) of participants felt that they had made an autonomous decision and most (10/12) seemed to have adjusted well to their test result. Reproductive factors were framed as having been a key motivator prior to testing. However, following testing, participants’ views on prenatal diagnosis seemed more closely linked to their lived experience than to their test result. Just over half (7/12) the participants reported having not had the opportunity for genetic counseling prior to testing and after receiving their result, an issue that warrants further consideration.

Outdated risk assessment in a family with Duchenne dystrophy: Implications for duty to reassess

Carrier risk assessment for Duchenne muscular dystrophy (DMD) is necessary to counsel women at risks of developing cardiomyopathy and having a child with DMD. Comprehensive molecular testing for dystrophin gene mutations has only been available since 2003¹; women counseled earlier have outdated risk assessments. We present a 5-generation family in whom results of familial mutation testing for DMD newly identified 10 obligate carriers and 28 women at risk to be carriers for DMD.

Knowledge of carrier status and barriers to testing among mothers of sons with Duchenne or Becker muscular dystrophy

Our study objective was to survey female carriers for Duchenne and Becker muscular dystrophy to identify barriers to carrier testing and the impact of carrier risk knowledge on cardiac and reproductive health management. We surveyed women who have or had biological sons with Duchenne or Becker muscular dystrophy and were enrolled in the US DuchenneConnect patient registry, with questions assessing knowledge of carrier status and recurrence risk, knowledge of care standards for carriers, and barriers to testing. Of the 182 eligible respondents, 25% did not know their carrier status and 14% incorrectly classified themselves as not at risk. Cost of testing was the most commonly identified barrier to testing. Women reporting unknown carrier status were 13 times as likely to express uncertainty regarding their recurrence risk compared to women reporting positive carrier status. 37% of women at an increased risk for cardiomyopathy had never had an echocardiogram. Women who were certain of their positive carrier status were twice as likely to have had an echocardiogram in the last five years compared to women with unknown carrier status. Future research on reducing barriers to counseling and carrier testing, such as cost, may improve care standard adherence.

Systemically-Based Psychotherapeutic Techniques in Genetic Counseling

The uses of systemically-based psychotherapeutic methods in genetic counseling are discussed in the context of the origin of genetic counseling, the definition of genetic counseling, and the adjustments that one must make in order to implement these methods. Selected systemic methods which can be readily incorporated into genetic counseling are presented: use of genograms to explore family attitudes and beliefs about genetic risk, communications skills, and applications of family of origin work in genetic counseling. The need for research regarding the methodology and process of genetic counseling is presented with discussion of the need for theories of practice for genetic counseling.

Molecular prenatal diagnosis: the impact of modern technologies

Originally prenatal diagnosis was confined to the diagnosis of metabolic disorders and depended on assaying enzyme levels in amniotic fluid. With the development of recombinant DNA technology, molecular diagnosis became possible for some genetic conditions late in the 1970s. Here we briefly review the history of molecular prenatal diagnostic testing, using Duchenne muscular dystrophy as an example, and describe how over the last 30 years we have moved from offering testing to a few affected individuals using techniques, such as Southern blotting to identify deletions, to more rapid and accurate PCR-based testing which identifies the precise change in dystrophin for a greater number of families. We discuss the potential for safer, earlier prenatal genetic diagnosis using cell free fetal DNA in maternal blood before concluding by speculating on how more recent techniques, such as next generation sequencing, might further impact on the potential for molecular prenatal testing. Progress is not without its challenges, and as cytogenetics and molecular genetics begin to unite into one, we foresee the main challenge will not be in identifying the genetic change, but rather in interpreting its significance, particularly in the prenatal setting where we frequently have no phenotype on which to base interpretation.

Communication and information-giving in high-risk breast cancer consultations: influence on patient outcomes

This longitudinal study aimed to document (i) the information-giving and patient-communication styles of clinical geneticists and genetic counsellors (consultants) in familial breast cancer clinics and (ii) assess the effect of these styles on women's knowledge, whether their expectations were met, satisfaction, risk perception and psychological status. A total of 158 women from high-risk breast cancer families completed self-report questionnaires at 2 weeks preconsultation and 4 weeks postconsultation. The consultations were audiotaped, transcribed and coded. Multivariate logistic regressions showed that discussing prophylactic mastectomy (P=0.00) and oophorectomy (P=0.01) led to women having significantly more expectations met; discussing genetic testing significantly decreased anxiety (P=0.03) and facilitating understanding significantly decreased depression (P=0.05). Receiving a summary letter of the consultation significantly lowered anxiety (P=0.01) and significantly increased the accuracy of perceived risk (P=0.02). Women whose consultant used more supportive communications experienced significantly more anxiety about breast cancer at the 4 weeks follow-up (P=0.00). These women were not significantly more anxious before genetic counselling. In conclusion, this study found that consultants vary in the amount of information they give and the way they communicate; and this variation can result in better or worse psychosocial outcomes. Greater use of supportive and counselling communications appeared to increase anxiety about breast cancer. Identifying methods to assist consultants to address emotional issues effectively may be helpful.

Genetic counseling follow-up - a retrospective study with a quantitative approach

The impact of genetic counseling (GC) was evaluated in families, who were interviewed at least two and half years and at most seven years after GC at the Genetics Service of the University Hospital, Faculty of Medicine of Ribeirão Preto, University of São Paulo (HC, FMRP, USP). The 113 families interviewed in this study were asked 48 questions and all children born after GC were studied clinically. We evaluated the families for spontaneous motivation for GC and understanding of GC information, their reproductive decisions, changes in the family after GC and the health status of new children. The majority of families seen at the Hospital das Clínicas de Ribeirão Preto were not spontaneously motivated to undergo GC. They had a low level of understanding about the information they received during GC. Generally families were using contraceptive methods (even when at low genetic risk) with a consequent low rate of pregnancies and children born after GC. These families also had a very low rate of child adoption and divorces when compared to other studies.

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.

Evaluation of genetic counselling: recall of information, post-counselling reproduction, and attitude of the counsellees

Of the families who had received genetic counselling between 1972 and 1981, 791 replied to a questionnaire which covered recall of information, post-counselling reproduction and attitudes towards counselling and prenatal diagnosis. Eighty percent had adequate knowledge of mode of inheritance and 74% of recurrence risk. Knowledge of mode of inheritance was poorest in multifactorial transmission (63%) and knowledge of recurrence risk in X-chromosomal disorders (61%). Forty-five per cent of the families had started a pregnancy after the counselling. 25%). Early lethality of the disorder and feasibility of a prenatal study contributed to positive reproductive decisions. Nine per cent of the children born after the counselling were affected by the disorder in question. The observed risks tended to match well with the expected ones. Sixty-two per cent of the respondents felt that the counselling had had a great or moderate impact on their reproductive plans. Forty-two per cent expressed a wish to hear the counsellor's opinion in addition to the facts. This was more common when the disorder was severe. Although most couples (53%) wished to have a prenatal study, if feasible, and abort an affected foetus, 16% were against abortion in such a case and 31% wished to have the study but were ambiguous about an abortion.

Fetal diagnosis of inborn errors of metabolism

Nearly 4000 different human disorders are supposed or known to be due to a single gene mutation. In about 10%, an early diagnosis is possible by the demonstration of specific abnormalities of metabolites in blood and/or urine, an abnormal structure/function of a particular (enzyme) protein or by the (in)direct demonstration of the gene mutation using DNA analysis. These methods of molecular analysis can often also be used for carrier detection. Early identification of couples at risk of handicapped offspring followed by genetic counselling forms the basis for prevention. Follow-up studies have shown that more than half of the couples at risk of a child with a genetic disease refrain from pregnancy. An important alternative for couples at risk is prenatal monitoring and selective abortion. During the last 10-15 years, the technology of fetal diagnosis of genetic diseases has improved and the number of Mendelian disorders that can be diagnosed in utero has increased to more than 100. In the second-trimester of pregnancy, about two dozen inborn errors of metabolism have been diagnosed by metabolite analysis of amniotic fluid supernatant using gas chromatography-mass spectrometry or electrophoretic methods. About 5000 pregnancies at risk of different types of haemoglobinopathy, haemophilia, alpha-1-antitrypsin deficiency and a few other diseases not expressed in amniotic fluid cells have been investigated by biochemical analysis after fetal blood sampling. The most common approach towards fetal diagnosis of inborn errors of metabolism has been the demonstration of a specific enzyme deficiency in cultured amniotic fluid cells. In this way some 60 different diseases have been diagnosed, usually after 2-4 weeks of cultivation after amniocentesis at 16 weeks gestation. In addition, some 20 other Mendelian disorders have been diagnosed in utero by ultrasonography and non-biochemical analysis of amniotic fluid cells or fetal skin biopsies. The introduction of chorionic villus sampling has offered the possibility of first-trimester fetal diagnosis of a large number of Mendelian disorders. The overall diagnostic experience until mid-1986 amounts to about 1500 pregnancies at risk. Some 45 different inborn errors have been diagnosed by enzyme assays directly on chorionic villus homogenate or after incubation with radiolabelled precursors of intact villi followed by chromatography or other types of analysis. In a few instances, cell cultivation for a period of 2-3 weeks is required to establish a reliable biochemical diagnosis.

Screening for Duchenne muscular dystrophy: an improved screening test for creatine kinase and its application in an infant screening program

A kinetic bioluminescence assay with optimized reagent conditions has been developed for application as a screening test for increased creatine kinase (CK) activities in dried blood spots. This test is used for the early detection of Duchenne muscular dystrophy (DMD) in a voluntary CK screening program in West Germany. Of the 176,600 boys tested up to December 31, 1984, 48 who were less than 6 months old had certain or probable DMD (frequency 1: 3679). In 1983 and 1984, the rate of false positive results was 0.016% for a cut-off activity 300 U/liter and 0.061% for a cut-off activity 180 U/liter. Long-term counseling is offered to families of newly detected DMD patients in order to facilitate the aims of the screening program, namely, avoidance of secondary cases in affected families, early professional care for the sick child, and the early opportunity to make the appropriate decisions for a life with an handicapped child. Two types of a benign hereditary blood anomaly were also detected by CK screening (CK-BB inside erythrocytes or thrombocytes).

Duchenne muscular dystrophy: pathogenetic aspects and genetic prevention

Duchenne muscular dystrophy (DMD) is the most common sex linked lethal disease in man (one case in about 4000 male live births). The patients are wheelchair bound around the age of 8-10 years and usually die before the age of 20 years. The mutation rate, estimated by different methods and from different population studies, is in the order of 7 X 10(-5), which is higher than for any other X-linked genetic disease. Moreover, unlike other X linked diseases such as hemophilia A or Lesh-Nyhan's disease, there seems to be no sex difference for the mutation rates in DMD. Several observations of DMD in girls bearing X-autosomal translocations and linkage studies on two X chromosomal DNA restriction fragment length polymorphisms indicate that the DMD locus is situated on the short arm of the X chromosome, between Xp11 and Xp22. It may be of considerable length, and perhaps consisting of actively coding and non-active intervening DNA sequences. Thus unequal crossing over during meiosis in females could theoretically account for a considerable proportion of new mutations. However, there is no structurally or functionally abnormal protein known that might represent the primary gene product, nor has any pathogenetic mechanism leading to the observed biochemical and histological alterations been elucidated. Among the numerous pathogenetic concepts the hypothesis of a structural or/and functional defect of the muscular plasma membrane is still the most attractive. It would explain both the excess of muscular constituents found in serum of patients and carriers, such as creatine kinase (CK), as well as the excessive calcium uptake by dystrophic muscle fibres, which, prior to necrosis, could lead to hypercontraction, rupture of myofilaments in adjacent sarcomeres and by excessive Ca uptake to mitochondrial damage causing crucial energy loss. The results of studies on structural and functional membrane abnormalities in cells other than muscle tissue, e.g., erythrocytes, lymphocytes and cultured fibroblasts, indicate that the DMD mutation is probably demonstrable in these tissues. However, most of the findings are still difficult to reproduce or even controversial. DMD is an incurable disease; therefore most effort, in research as well as in practical medicine, is concentrated upon its prevention.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of genetic counseling on Duchenne muscular dystrophy families in Brazil

We report the preliminary results of a follow-up study of 574 females at-risk for Duchenne dystrophy, recontacted 3 to 13 yr after genetic counseling (GC). Among them, 290 are younger than 18 yr or still unmarried. The effectiveness of GC (reproductive performance) in the remaining group is analyzed in terms of procreation, rate of sterilization, and mean number of children. The observed data suggest that females at-risk involved in GC had about 169 children less than their normal, nonaffected brothers. In terms of prevention this would correspond roughly to 42 Duchenne affected boys and 42 carrier girls.

Psychological aspects of genetic counseling. II: Quantitative analysis of a transcript of a genetic counseling session

The Bales system of scoring small group interactions was used to analyze a transcript of a preamniocentesis (genetic) counseling session in which a husband (H), wife (W), and a male counselor (C) participated. Scoring required the subdivision of communication into the smallest meaningful and scorable units, assigning each unit one of twelve possible category scores and designating the initiator and intended recipient(s) of the unit. The categories included "positive" and "negative" reactions, questions and attempted answers. Over half the units were found to consist of interactions in which information, orientation, and clarification were provided. C initiated 54% of all units of which three-quarters consisted of factual information regarding amniocentesis, genetic risks, Down syndrome, and mental retardation. C interacted significantly more frequently with W than with H, but units directed toward H were significantly more positive than those toward W. One interaction, in which C responded to affective material, significantly altered the subsequent frequency and direction of units; H became more verbal and there was an increase in further affective expression. Although evidence of persuasion was present, no directiveness was demonstrated. The data show that quantitative study of genetic counseling is feasible. Further research on different counseling styles and on the influence of specific interventions on later outcome has been undertaken.

Feasibility of neonatal screening for Duchenne muscular dystrophy

During the period November 1976 to September 1980, 2703 babies born in one Edinburgh hospital were screened in the neonatal period by estimation of their serum creatine kinase levels for Duchenne muscular dystrophy. Among the 2336 male babies tested, none proved to be affected and only 16 required second specimens to be obtained. Overall the false positive rate in the study was 0.78%. This study confirms that neonatal screening for Duchenne muscular dystrophy is feasible in a British hospital setting and is here most conveniently carried out on the 5th day of life along with routine testing for phenylketonuria.

Analysis of a follow-up study of genetic counseling

A follow-up study of 212 families for whom genetic counseling had been provided was performed to assess the effectiveness of the non-directive genetic counseling service at the Mount Sinai Medical Center in New York City. The preliminary result have been reported previously (Godmilow & Hirschhorn 1977). Of those families surveyed, 72% responded. Adequate recall of the genetic information was demonstrated by 74% of those responding, and 80% described their counseling experience as favorable. A direct relationship was noted between the degree of satisfaction and whether or not the counselees received the mode of counseling they preferred, i.e., individual versus team. Sixty-two percent of those counselees reaching a procreative decision indicated that genetic counseling had influenced their decision making. A significant correlation was noted between the magnitude of the occurrence or recurrence risk and the procreative decisions reached. However, some decisions were modified by the counselees' subjective interpretation of the burden associated with the disorder in question. It is concluded that follow-up of genetic counseling by questionnaire, together with statistical analysis of the data received, can provide the genetic center with valuable information regarding strengths and weaknesses of the counseling program and can suggest ways to improve the counseling process and thereby enhance its effectiveness.

Impact of genetic counseling: a review of published follow-up studies

Retrospective follow-up studies on the impact of genetic conseling, published since 1970, are reviewed in the present paper. Particular attention has been paid to evaluation of understanding of genetic information, planning of later pregnancies and real changes in family composition. A rather wide divergence was found with regard to these three parameters, probably more related to the design of the studies than to a divergence in counselees' understanding and decisions, emphasizing that more, and especially more methodologically sound studies are necessary to evaluate the impact of genetic counseling.

Genetic counseling--the postcounseling period: I. Parents' perceptions of uncertainty

To investigate how parents who have had genetic counseling perceive the problems created by being at risk, transcripts of open-ended, semistructured follow-up interviews with 53 counselees were analyzed qualitatively. Rate information, though recalled accurately by parents considering further childbearing, was discounted as impersonal, and subjects overwhelmingly perceived the chance of recurrence in binary form -- it either will or will not happen. By processing rates this way, they simplified probabilistic information and shifted their focus to the implications of being at risk and the potential impact of that which might or might not occur. The many uncertainties they faced, the "consequences" of being at risk that parents felt had to be resolved during the decision-making process, fell into 3 major categories: uncertainty that arose because of the ambiguous impact and meaning of having an affected child; uncertainty about how to make a choice and how others would view it, the burden of decision-making; and uncertainty about their ability to fulfill their roles as parents. These issues were perceived as part of the problem to be resolved and were consolidated into "scenarios" in which the parents "tried out the worst." This analysis of counselees' perceptions of the problems created by being at genetic risk suggests that parents may process the disparate facts of their situation in common ways that emphasize their uncertainty, and it indicates that how parents perceive factual information may be more important in orienting their deliberations than what these facts (diagnosis, prognosis, risks) actually are.

Genetic counseling: provision and reception of information

To explore verbal communication between family and counselor, transcripts of 30 tape-recorded or observed genetic counseling sessions are analyzed qualitatively. In half the cases, available data did not allow counselors to give parents a single estimate of the recurrence rate. Moreover, limits on the language available for communicating small probabilities made common the use of nonnumerical statements about a family's chance of having an abnormal child. Counselees processed the factual information they were given, most commonly translating recurrence rates in ways that emphasized the uncertainties associated with them. They tended to view these rates in binary form and requested guidelines for their behavior, indicating uncertainty about how to proceed with reproductive decision-making. The findings suggest that strategies for processing information are an important element influencing parental perspectives on and approaches to the problems created by being at-risk and to possible courses of action.

Use of creatine kinase for detecting severe X-linked muscular dystrophy carriers

Women thought to be at risk of being carriers of Duchenne muscular dystrophy were given "odds" against their having an affected child. These were calcuated from a combination of the genetic risk from the family history and an estimation of the biochemical risk from measuring the serum creatine kinase concentration. The women were told the actual risk estimate and it was put into perspective for them as a high, medium, or low risk. Of 25 women at high risk six have had children, all girls; the two in the medium-risk group have had no children; and the 46 women at low risk have had 19 boys and 25 girls. None of the boys has the disease. With detailed counselling most potential carriers of this disease reach decisions in child bearing that are in line with their degree of risk.

Social effects of genetic counselling

In a follow-up study of 104 subjects referred for genetic counselling between 1965 and 1969 all were at risk of having children with a variety of serious genetic disorders. Most subjects were in social classes III and IV, were married, in their late 20s, and already had an affected child. Sixty-three per cent. were referred by hospital consultants, 27% by their general practitioners, and 10% were self-referrals. All of those counselled appeared to have appreciated the genetic implications, although four overestimated the risks and 11 underestimated the risks.Of those at high risk (greater than 1 in 10) of having an affected child 10 out of 55 couples "planned" further pregnancies despite the risks. In two this was because they had been unable to adopt a child, in four because they had no living children and the disorders in question usually resulted in stillbirth or death in infancy so that the "burden" of an affected child would be of relatively short duration, and one mother had had antenatal diagnosis and selective abortion. Most of the couples in the low-risk group (less than 1 in 20) were reassured and planned further pregnancies.