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Biomedical subjects

A Tibben

Publications and source records attributed to A Tibben.

At least 55 records · Page 3Linked to original sources
PubMed1997

Preparing for presymptomatic DNA testing for early onset Alzheimer's disease/cerebral haemorrhage and hereditary Pick disease.

The acceptability of presymptomatic testing in 21 people at 50% risk for the APP-692 mutation causing presenile Alzheimer's disease or cerebral haemorrhage resulting from cerebral amyloid angiopathy (FAD-CH), and in 43 people at 50% risk for hereditary Pick disease (HPD) was assessed. Neither group differed in demographic variables. Thirty-nine people (64%) in the whole group would request presymptomatic testing if it were clinically available, although two-thirds did not yet feel ready to take it. The most important reasons in the HPD and FAD-CH group for taking the test were: to further basic research (42% and 47%, respectively), informing children (47% and 50%, respectively), future planning (29% and 47%, respectively), and relieving uncertainty (46% and 27%, respectively). The most commonly cited effect of an unfavourable test result concerned increasing problems for spouses (75% and 76%, respectively) and children (61% and 57%, respectively). Most respondents denied that an unfavourable result would have adverse effects on personal mood or relationship. One-third of all respondents favoured prenatal testing where one of the parents had an increased risk for HPD or FAD-CH. Participants would encourage their offspring to have the test before starting a relationship (35%) and before family planning (44%). Thirty-seven percent of the respondents would encourage their children to opt for prenatal diagnosis. People at risk for HPD were significantly more preoccupied with the occurrence of potential symptoms in themselves, compared with those at risk for FAD-CH, reflecting the devastating impact that disinhibition in the affected patient has on the family. Our findings underline the need for adequate counselling and the availability of professional and community resources to deal with the impact of test results in subjects and their relatives.

Adult↗
PubMed1997

DNA testing for fragile X syndrome: implications for parents and family.

The fragile X syndrome is an X linked, semidominant mental retardation disorder caused by the amplification of a CGG repeat in the 5' UTR of the FMR1 gene. Nineteen fragile X families in which the mutated FMR1 gene segregated were evaluated. The implications of the diagnosis for the parents and family were studied through pedigree information, interviews, and questionnaires. Information about the heredity of fragile X syndrome was only disseminated by family members to a third (124/366) of the relatives with an a priori risk of being a carrier of the fragile X syndrome. Twenty-six percent (94/366) of the relatives were tested. Transmission of information among first degree relatives seemed satisfactory but dropped off sharply with increasing distance of the genetic relationship, leaving 66% uninformed. This is particularly disadvantageous in an X linked disease. Of those subjects tested, 42% (39/94) had a premutation and 18% (17/94) had a full mutation. On average, in each family one new fragile X patient and two new carriers were found. When people have the task of transmitting genetic information to their relatives, they usually feel responsible and capable; however, reduced acquaintance and contact with more distant relative severely reduces the effectiveness of such transfer of information in fragile X families.

Adolescent↗
PubMed1997

Psychological distress in applicants for predictive DNA testing for autosomal dominant, heritable, late onset disorders. The Rotterdam/Leiden Genetics Workgroup.

In a comparative study on the effects of predictive DNA testing for late onset disorders, pre-test psychological distress was assessed in people at risk for Huntington's disease (HD, n = 41), cerebral haemorrhage (HCHWA-D, n = 9), breast and ovarian cancer (HBOC, n = 24), and polyposis coli (FAP, n = 45). Partners, if available, also participated in the study. Distress was measured with the subscales Intrusion and Avoidance of the Impact of Event Scale. People at risk for the neurodegenerative disorders reported more avoidance than those at risk for the cancer syndromes. People at risk for FAP and partners of those at risk for HBOC reported less intrusion than the others at risk and the other partners. Subjects who were more distressed reported more experiences with the disease in close relatives, the disease having a great impact on their lives, having considerations against predictive testing, expecting that being identified as a gene carrier would have adverse effects, and expecting relief after being identified as a non-carrier. Test candidates who expected an increase of personal problems showed higher avoidance, whereas those who could better anticipate future life as a carrier had higher intrusion levels. Generally, subjects with high distress levels are of more concern to the healthcare professional than those with low distress levels. However, high distress may reflect worrying as a mental preparation for the test result, whereas low distress may indicate denial-avoidance behaviour and poor anticipation of the test outcome. In pre-test counselling sessions, this should be acknowledged and addressed.

Adenomatous Polyposis Coli↗
PubMed1997

Intelligence indices in people with a high/low risk for developing Huntington's disease.

Intelligence in 20 presymptomatic subjects with an increased risk (> 95%) for carrying the gene for Huntington's disease (HD) was studied in a prospective, case-control, single blind study. No significant differences between the groups were detected for intelligence indices and subtest scores (Wechsler Adult Intelligence Scale). The high level of the performance IQ and the significant discrepancy between performance IQ and verbal IQ found in both the high risk and the low risk groups contrasted with our expectations based on anamnestic information, general clinical opinion, and the results of previously conducted studies. We propose that psychosocial circumstances could explain the test results and discuss the consequences of our findings for clinical genetics practice.

Adult↗
PubMed1994

Predictive testing for Huntington disease: nonparticipants compared with participants in the Dutch program.

Attitudes toward predictive testing programs, in individuals who choose not to undertake the test (i.e., nonparticipants), may be influenced by fears of an unfavorable result. The reasons not to participate in predictive testing programs for Huntington disease (HD) were studied in members of the Dutch Huntington Association who were at 50% risk. They had completed the same baseline psychological questionnaires as had the participants in the Dutch DNA-testing program. The group of 34 nonparticipants was similar to the tested participants in the Dutch predictive testing program, with respect to average age (31.1 years), male:female ratio (1:2), the frequency of a stable relationship (70%), and level of education (67% had high school education or higher). Testing did not seem to be a realistic option for nonparticipants for improving their quality of life. In comparison with participants, nonparticipants had a significantly more pessimistic outlook on themselves and their futures. When asked to consider the possibility of an unfavorable result, nonparticipants expected more difficulties in their families; more problems for their children, their partners, and themselves; a lowered quality of life; and, more often, a depressive reaction. In their opinion, a favorable result would reduce the problems for their children but not for themselves, a result that was found more often in the nonparticipant than in the participant group. Nonparticipants learned about their being at risk for HD during adolescence (mean age 15.6 years), whereas participants did so in adulthood (mean age 22.7 years). The nonparticipants' attitude toward the test might be explained by the influence of HD in the adolescent's separation-individuation process and personality development. This finding could be relevant for future research and for the discussion about testing minors for delayed-onset disorders.

Adult↗
PubMed1993

Presymptomatic DNA testing for Huntington disease: identifying the need for psychological intervention.

UNLABELLED: In the Dutch presymptomatic DNA-testing program for Huntington disease (HD), 29 individuals with increased risk and 44 with decreased risk were followed-up 6 months after test results. A prognostic model was built aimed at identifying individuals at risk for psychological maladjustment, as measured by the Impact of Event Scale, the Beck Hopelessness Scale, the General Health Questionnaire, and the Social Support Questionnaire. RESULTS: 1) The more that applicants suffered from intrusive feelings about HD and tried to avoid HD-related situations, prior to the test, the greater the chance that they will experience this 6 months after the test if they proved to be at increased risk; 2) the more that both individuals with increased risk and those with decreased risk who suffered from the threat of having HD tried to avoid HD-related situations prior to the test and the less satisfied they were with available support, the greater the probability that they will show avoidance behavior after the test; 3) the more pessimistic that individuals with increased risk as well as those with decreased risk were about their future prior to the test, the more they avoided HD-related situations and the more dissatisfied they were about their available support (pretest), the greater the probability that they will become depressive and suicidal. Psychological adjustment was also studied as a function of a) intrusion/denial-avoidance pattern over time and b) healthy mental functioning/future expectancies. Most individuals with increased risk (86%) seem to cope well thus far, although this was based largely on strong psychological defenses and dependent on satisfactory relationships.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

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

Adult↗
PubMed1993

Presymptomatic DNA-testing for Huntington disease: pretest attitudes and expectations of applicants and their partners in the Dutch program.

We studied the baseline attitudes, prior to testing, of 70 applicants at risk for Huntington disease (HD) and their partners in the Dutch presymptomatic DNA-testing program. Two thirds of the applicants were female; 36% already had children. The main reason (60%) for undertaking the test was for family planning. Other reasons were either to reduce uncertainty (43%) or to obtain certainty (38%). Partners of applicants stated that planning for the future was for them the most important reason (76%). Significantly more at-risk females (42%) than males (16%) anticipated an unfavorable test outcome. Quite remarkably, most applicants and partners denied that a positive result might have adverse effects on either personal mood, quality of life, or marriage. Only a few did not expect that a favorable result would induce relief. The eventual outcome of the test was expected to enable applicants to gain control over their future, whatever the results. Hence, we propose that the applicants form a self-selected group, based on their expectation that they will not be emotionally affected by either result.

Adult↗
PubMed1993

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.

Adult↗
PubMed1992

DNA-testing for Huntington's disease in The Netherlands: a retrospective study on psychosocial effects.

Presymptomatic DNA-testing for Huntington's disease has made it possible to predict whether or not at-risk individuals are gene-carriers with a reliability of about 98%. In our retrospective study of 18 tested individuals, most of the newly identified carriers function apparently well. They use avoidance and repression of affect as psychological defense strategies. However, 8 out of 9 non-carriers do not experience the expected relief about their test results. They experience survivor guilt and emotional numbness and find it difficult to cope with the effects of the test results on the family system. The partners of gene-carriers are at risk of becoming emotionally isolated by putting aside their own feelings for fear of seeming self-centered. Appreciation of these effects on tested individuals is important and professional support is needed to prevent post-traumatic stress disorders. Whatever the test result may be, the working through process may take years rather than months. These findings have important implications for patient care and necessitate an extended period of observation after presymptomatic testing.

Adult↗
PubMed1990

[Presymptomatic DNA diagnosis in Huntington's chorea: reactions to the certainty of not being a genetic carrier].

Presymptomatic DNA diagnostics in Huntington's chorea make it possible to establish with approx. 98% certainty whether an at-risk person is a gene carrier. Sympathy and care are usually shown to those demonstrated to have the gene and so will become affected in the future. Persons shown not to be carriers sometimes do not experience the expected relief. The authors successively discuss the effects of a favourable finding on the family system, such as survivor's guilt and emotional numbing as aspects of a coping process. It is concluded that even a favourable finding needs to be worked through, a process that takes years rather than months.

Adult↗
PubMed1990

[Procedure and initial results of presymptomatic DNA studies in Huntington's chorea].

The availability of DNA-markers more tightly linked to the Huntington's disease locus made presymptomatic and exclusion testing possible with an accuracy of up to 98%. The testing programme started in Leiden in August 1987. In 56 adults with 25% and 50% risks presymptomatic tests were performed. In 8 persons the risk was increased to 98%, in 17 it was decreased to less than 5%. In two instances the test was not informative. The remaining 29 persons have not yet been tested for different reasons. So far 3 exclusion tests were requested: one showed a decreased risk, one has not yet been performed and one request was rejected. The results and the reactions to the test are discussed.

Adolescent↗