A mark on the arm: myths of carrier status in sibs of individuals with ataxia-telangiectasia

Risk perception before and after presymptomatic genetic testing for Huntington's disease: Not always what one might expect

Background

In 1983, Huntington's disease (HD) was the first genetic disease mapped using DNA polymorphisms. Shortly thereafter, presymptomatic genetic testing for HD began in the context of two research studies. One of these trials was at the Johns Hopkins University Huntington's Disease Center.

Methods

As part of the protocol, risk perception (RP) values were collected at 16 time points before and after testing. The current study investigated changes in RP scores before and after genetic testing. Of the 186 participants with pre‐ and post‐testing RP values, 39 also had contemporaneous research clinic notes and recent semi‐structured interviews available for analysis.

Results

The data reveal tremendous diversity in RP. While the RP scores of most individuals change in the way one would expect, 27% of participants demonstrated unexpected changes in RP after disclosure. A significantly higher proportion of individuals who received an expanded repeat result had unexpected changes in RP, compared with those who received normal repeat results.

Conclusions

The data suggest that individuals’ RP is influenced by more than merely the results of genetic testing. This finding is important for genetic counselors and healthcare providers, as it suggests that even comprehensive patient education and disclosure of genetic test results may not ensure that people fully appreciate their disease risk.

Carrier testing in children and adolescents

Many international guidelines recommend that carrier testing in minors should be postponed either until the age of majority or until the child can be actively involved in the decision making process. Although a number of high school programs exist which provide carrier screening to adolescents in at-risk populations, recent guidelines published by the American Society of Human Genetics do not advocate this testing. Despite this, there are some circumstances in which carrier testing does occur in minors. This testing might be intentional, in which identification of carrier status is the goal of the test, or unintentional, where carrier status is identified as a by-product of testing. In this review we outline the situations in which carriers may be identified in childhood and the positions of professional guidelines that address carrier testing in children. We then review the arguments for and against carrier testing presented in the literature and compare this to the empirical evidence in this field.

Parental Communication and Experiences and Knowledge of Adolescent Siblings of Children with 22q11.2 Deletion Syndrome

22q11.2 deletion syndrome (22q11DS) is the most common microdeletion in humans. There have been few studies assessing the impact of this condition on the family and no previous studies conducted on unaffected siblings of children with 22q11DS. The goal of this study was to determine the frequency, method, and content of information being communicated by parents to unaffected siblings about the condition and to assess unaffected siblings' knowledge of 22q11DS and perceptions of the impact of the condition on their affected sibling and themselves. Families were recruited from several 22q11DS educational and support organizations and asked to complete a single anonymous online survey. Families were eligible to participate if they had one child with 22q11DS and at least one unaffected child between the ages of 12 and 17. Survey questions were developed based on previous literature and authors' expertise with individuals with 22q11DS. Responses to quantitative and qualitative questions were analyzed to calculate frequencies and proportions and to extract themes, respectively. A total of 25 families (defined as a unit of at least one parent, one affected child, and at least one unaffected child) participated in the study. Parents shared genetic information less often as compared to behavioral and medical information. Siblings of children with 22q11DS had both positive and negative experiences in having a brother or sister with this condition. Genetic counselors can use the results of this study to develop anticipatory guidance for parents of children with 22q11DS in talking with their unaffected children about the condition.

Quality assessment of genetic counseling process in the context of presymptomatic testing for late-onset disorders: a thematic analysis of three review articles

Presymptomatic testing (PST) is available for a range of late-onset disorders. Health practitioners generally follow guidelines regarding appropriate number of counseling sessions, involvement of multidisciplinary teams, topics for pretest discussion, and follow-up sessions; however, more understanding is needed about what helps consultands effectively and the impact of amount and quality of genetic counseling on the psychosocial sequelae of PST for late-onset disorders. We conducted a thematic analysis of three review articles on quality of the genetic counseling process, aiming at (1) exploring current evidence; (2) identifying quality assessment indicators; and (3) making recommendations for genetic counseling practice in late-onset disorders. We undertook a systematic search of 6 relevant databases: 38 articles were identified and 3 fitted our inclusion criteria; after quality appraisal, all were included in the review. The number of sessions, time spent, consultation environment, follow-up, and multidisciplinarity were identified as variables for quality assessment. Research on counseling in the context of genetic testing in familial cancer tends to be related to outcomes and indicators for quality assessment, while research concerning other late-onset diseases is mainly focused on the psychological impact of the test results. The quality and content of the overall process in noncancer late-onset diseases is insufficiently articulated. Despite the fact that PST for Huntington disease and other degenerative conditions has been offered for more than 20 years, good methodological approaches to assess quality of genetic counseling in that context remain elusive. This restricts improvement of the protocols for genetic services and, in general, healthcare for the at-risk population.

Constructing "best interests": genetic testing of children in families with hypertrophic cardiomyopathy

Professional guidelines on genetic testing of children have recently shifted their focus from protecting the child's autonomous choice to professionals, together with parents, striving to work in the child's "best interest." This notion of "best interest" allows room for therapeutical as well as psychological and social considerations, and gives rise to the question how parents and professionals weigh up the child's best interest in practice. In this qualitative study, we followed six extended families involved in genetic testing for hypertrophic cardiomyopathy in the Netherlands for 3½ years. In total 57 members of these families were interviewed in depth; many of them more than once. Our empirical analysis shows that the best interest of a child is constructed via long-term processes in the broader context of family and kin. In this context, "best interests" are considered and reconsidered. We conclude that a child's best interest should not be framed as the result of an instantaneous agreement between parents and professionals. In dealing with genetic testing of children, parents as well as professionals reflect on and learn from the processes of generating new meanings of "best interest." To enable professionals to deal with the variety in family life, these learning processes should be documented closely.

Cool, but is it credible? Adolescents' and parents' approaches to genetic testing

Advances in genomic science create both opportunities and challenges for future generations. Both adolescents and adults may benefit or be harmed by decisions they make in response to this new science. Using a qualitative descriptive design, the authors interviewed 22 adolescents (11 who were aged 14-17 years and 11 who were 18-21 years) and 11 parents to determine levels of knowledge and approaches to decision making. It was found that younger adolescents and their parents have very limited knowledge about genetics and genetic testing. Older adolescents have more complete information and consider a broader range of points in making decisions about hypothetical situations involving genetic testing. Adolescents and parents need much more information to enhance their ability to make decisions about using genetic services. These findings have implications for developing interventions and public health policy highlighted by the need for improved education about the benefits and harms of genetic testing.

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.

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.

Attitudes toward prenatal screening and testing for Fragile X

PURPOSE

Currently, the American Colleges of Medical Genetics and Obstetrics and Gynecology recommend screening in the prenatal setting only for individuals with specific family history indicators. Our aims were to study patient attitudes and psychologic impact of offering widespread screening for Fragile X in a prenatal setting.

METHODS

Participants were recruited from pregnant women referred for "Prenatal Diagnosis Options" counseling by their primary provider in the first trimester of pregnancy.

RESULTS

Pretest knowledge about Fragile X was limited; 33% had heard of Fragile X syndrome before enrollment. Postcounseling knowledge was similarly limited; only 30% accurately understood the 50% risk for girls. Participants were strongly in favor of being tested or screened, and did not experience undue anxiety related to Fragile X testing. Respondents hoped that knowledge of Fragile X in the general population would increase, and recommended that screening be offered during routine prenatal care.

CONCLUSION

Fragile X screening in this setting was a favorable testing experience for the participants. Limited pretest knowledge and posttest retention of specific genetic information on Fragile X suggest that widespread screening will pose significant counseling and educational challenges, which should be addressed in such programs.

"You have shown me my end": attitudes toward presymptomatic testing for familial amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a lethal degenerative motor neuron disease. Approximately, 5-10% of cases of ALS are familial (FALS), inherited primarily as an autosomal dominant trait. Recently, mutations in Cu/Zn superoxide dismutase (SOD1) have been identified; 15-20% of familial cases carry this mutation, providing a marker for diagnosis, carrier testing, and prenatal detection. We assessed understanding of genetics of FALS in relatives of patients cared for at the Forbes Norris MDA/ALS Research Center in San Francisco. A total of 25 participants completed a questionnaire and semistructured interview. Of these, 60% would have gene testing for themselves; 36% believed testing of children or adolescents was a good idea. Overall knowledge of genetics of FALS was limited. Also, 24% of respondents understood the inheritance pattern of FALS; 64% were aware that not all individuals who had the gene would show symptoms in their lifetime. Families were confused about whether they would receive results from linkage studies. We recommend that: (1) physicians refer relatives of newly diagnosed individuals for genetic counseling and possibly psychological counseling; (2) investigators ensure that participants comprehend the purpose of gene identification is for research, not disclosure of individual results; (3) families be helped to understand how to keep abreast of medical and genetic advances; (4) following the model of Huntington disease (HD), consensus guidelines for FALS genetic counseling and testing be developed.

Attitudes and psychosocial adjustment of unaffected siblings of patients with phenylketonuria

Sibling illness may contribute to an increased risk of adjustment problems in healthy siblings. Previous studies have reported a variety of effects on healthy individuals who have an ill sibling, but the psychosocial effects of treatable inherited disease on healthy siblings have not yet been investigated. We report the results of a survey study conducted in families with both unaffected and affected children with classic phenylketonuria (PKU), an inherited inborn error of metabolism. The survey included a knowledge test about PKU, and four previously validated instruments designed to assess psychosocial adjustment of unaffected siblings compared to age and sex matched norms. The responses revealed that unaffected adolescent and adult siblings had gaps in their knowledge about the genetic basis of PKU, and had evidence for the presence of adverse psychosocial sequelae. These findings suggest a role for genetic services providers, including genetic counselors, in assisting all members of a family adjust, when the diagnosis of an inborn error of metabolism has been made.

?The Lion, the Witch and the Wardrobe?: Impact on sibs of individuals with AAT deficiency

Alpha(1)-antitrypsin (AAT) deficiency is a genetic disorder that may cause serious pulmonary or liver impairment in children or adults. Although genetic sequencing of the AAT gene has only been available for 20 years, analysis of the amount and electrophoretic mobility of the AAT protein has allowed clinical phenotyping for more than 40 years. There have been no studies assessing the psychological impact of having a sib affected by AAT deficiency. Twenty-five participants drawn from the Alpha-1 Research Registry completed a questionnaire and semi-structured interview. Respondents were supportive of testing prior to adulthood for AAT status; 18 thought it was a good idea to test a child, three did not know, and four said children should not be tested, primarily citing insurance concerns. Of those 18 who stated it was a good idea, 14 would test at birth. Knowledge of genetics of AAT deficiency was limited; only 44% of respondents understood the inheritance pattern. We recommend: (1) parents and sibs need help in mourning the loss of children with AAT deficiency; young sibs are at risk for trauma and long-term developmental problems. (2) Teams evaluating donors for liver transplantation should be aggressive in ruling out AAT deficiency prior to invasive testing. (3) Testing should be offered to individuals with a family history of AAT deficiency to obtain the health benefits of lifestyle modification and limit the burden of disease discovery in symptomatic relatives. (4) Awareness of liver disease from AAT deficiency should be increased.

Perceptions of reproductive risk and carrier testing among adolescent sisters of males with chronic granulomatous disease

Although recent research has investigated the attitudes of parents, professionals, and adult siblings toward carrier testing of minors, no studies have focused on the experiences of minor siblings of individuals with X-linked and autosomal recessive conditions. To explore adolescent sisters' perceptions of their reproductive risks, attitudes toward carrier testing, and resources for information and support, we interviewed 14 parents and 9 sisters (ages 12-15) of males with chronic granulomatous disease (CGD), a primary immunodeficiency disorder inherited in both an X-linked recessive and autosomal recessive fashion. Our semistructured telephone interviews were audiotaped, transcribed, and subjected to template analysis (a common qualitative methodology). Girls were all aware that CGD is an inherited condition and each had made an assessment of her reproductive risk. All girls considered their parents to be their best source of information and support, but girls had trouble initiating discussions for fear of upsetting their parents. All girls and parents considered eventual carrier testing vital for reproductive decision-making and relationship-building. However, girls favored carrier testing at a later age and expressed more concerns about psychological risks associated with testing than did their parents. When faced with the hypothetical situation of being offered carrier testing "tomorrow," half of the parents and untested daughters disagreed on the desirability of the test, with parents more likely to favor testing. Including adolescent sisters in family-based genetic counseling that provides an opportunity for age-appropriate discussion of inheritance and the timing, risks, and benefits of carrier testing would be beneficial to them. Published 2003 Wiley-Liss, Inc.

"My crooked vision": the well sib views ataxia-telangiectasia

The ataxia-telangiectasia gene (designated ATM) has been identified by positional cloning. Retrospective studies in cystic fibrosis (CF) have shown that the illness and death of a sib have far-reaching ramifications on the surviving sib's life. However, there have been no studies on sibs of children and adults with ataxia-telangiectasia (A-T). Thirty-five sibs from 24 families, including 26 adults and 9 adolescents, were drawn from the University of California, Los Angeles; the A-T Clinical Center at the Johns Hopkins University School of Medicine; and the A-T Children's Project Interviews indicated that, unlike CF, the visibility of A-T caused less resentment of time or attention given to the affected, less guilt, and less identification or idealization of the affected, but more embarrassment and shame. It may be said that, unlike CF, the dynamic is one of burden rather than trauma. The specific phenotypic expression of a genetic illness predisposes the way in which the well sib will encounter problems. In A-T affected families, one must help families locate caregiving resources so they will not burden their well children; sibs need help with managing feelings of embarrassment and shame. Geneticists must be alert to understanding characteristic differences of disorders they encounter in order to offer the most appropriate support to affected families.

Never again joy without sorrow: the effect on parents of a child with ataxia-telangiectasia

The purpose of this study was to explore the impact of having a child with ataxia-telangiectasia (A-T) as well as to assess parental understanding of the genetics of A-T and attitudes toward carrier testing. Sixty-eight parents of individuals with A-T were interviewed. Ninety percent of the parents correctly believed if there is a child with A-T, both are obligate heterozygotes. Only 9% knew each well sib had a two-thirds chance of being a carrier. Eighty-four percent would have their unaffected child tested for carrier status prior to age 18 years. Eighty-two percent believed heterozygosity is associated with increased health risks. We offer the following recommendations. 1) Physicians must realize that communicating the possibility of early death is difficult; parents need guidelines so they know what to expect, but diagnosis should not be a death sentence. Clinicians should stress individual variations in expression of the disorder and offer hope for future progress in treatment. 2) Parents underestimated carrier risks for the well sib and the frequency of carrier status in the general population. Although these distortions are self-protective, they interfere with transmission of accurate genetic information to their children. Parents should be referred to genetic counseling. 3) Psychological counseling should be offered to families at the time of diagnosis so parents can support each other, the affected, and unaffected offspring.