Machado-Joseph disease [MJD, also spinocerebellar ataxia type 3 (SCA3)] and familial amyloid polyneuropathy type I (FAP-I or ATTR V30M) are neurodegenerative disorders, inherited in an autosomal dominant fashion, which have a high prevalence in Portugal, probably due to a founder effect. MJD and FAP-I are late-onset diseases, with symptoms emerging usually during adulthood. CGPP, which is the national reference centre for these disorders, has a genetic lab that offers diagnostic, pre-symptomatic and prenatal testing and an outpatient clinic to counsel and follow relatives at risk for hereditary ataxias, FAP-I and Huntington disease (HD). The present work is a review of our 10-year experience with psychological counselling of individuals at risk for MJD and FAP-I. Persons at risk for FAP-I may show a better response to pre-symptomatic testing than those who are at risk for MJD and HD because of the availability of liver transplantation, which may improve their health and life expectancy. Psychological well-being and specific distress of MJD and FAP-I test applicants, before undergoing genetic testing (baseline level) and 3 to 6 months after disclosure of test results, have shown a low level of change, both in identified carriers and non-carriers. A major goal of psychological characterization of at-risk individuals for MJD and FAP-I is to determine the factors that influence the uptake of genetic testing.
Introduction: The national protocol of genetic counselling and pre-symptomatic testing for late-onset neurological diseases began in Portugal in 1995. Initially, it was accessible only to adults at-risk for Machado-Joseph disease, but was later extended to other hereditary ataxias, to Huntington’s disease and to familial amyloid polyneuropathy caused by Val30Met mutation at the transthyretin gene. The aim of this study was to describe the profile of the population seeking pre-symptomatic testing, while also reflecting on the experience of conducting the protocol of multidisciplinary sessions since 1996.Material and Methods: We conducted a retrospective study and collected data from clinical records of consultands who requested pre-symptomatic testing at our centre in Porto (Portugal) during the first twenty years of practice (1996 - 2015).Results: A total of 1446 records were reviewed. The most common reason for testing was to reduce uncertainty (41.7%). The rate of withdrawals before results disclosure was lower (16%) than reported in other international experiences with pre-symptomatic testing, while 45% of the consultands dropped out the protocol after learning the test results (73.5% of them were non-carriers). As far as the mutation carriers were concerned, 29.6% adhered to the protocol a year after test disclosure. Consultands that had learned about presymptomatic testing through healthcare professionals tended to adhere more to pre-symptomatic testing consultations.Discussion: The profile of Portuguese consultands at risk for late-onset neurological diseases is similar to those reported in other international programs. The largest group in this data set was the one comprising the subjects at risk for familial amyloid polyneuropathy caused by Val30Met mutation at the transthyretin gene, and it is likely that therapeutic options for this condition may have influenced this result. Adherence to pre-symptomatic testing may change in the future since effective therapies are available (or given the fact that people think effective treatments are imminent).Conclusion: This study reflects the first comprehensive description of a Portuguese experience with pre-symptomatic testing for late onset neurological diseases. The development of innovative approaches to improve the consultands’ experience with pre-symptomatic testing and their engagement in genetic departments is still a challenge in Portuguese genetics healthcare departments. A better coordination among primary care and genetics healthcare services is needed.
Objective: To study anxiety as a variable of the mid-and long-term psychological impact of presymptomatic testing for three autosomal dominant late-onset disorders -Huntington's disease (HD), Machado-Joseph disease (MJD) and familial amyloid polyneuropathy (FAP) TTR V30M -in a Portuguese sample. Methods: This cross-sectional study included 203 participants: 170 (83.7%) underwent pre-symptomatic testing for FAP, 29 (14.3%) for HD, and 4 (2%) for MJD. Of the 203 participants, 73 (36.0%) were asymptomatic carriers, 29 (14.5%) were symptomatic carriers, 9 (4.5%) were diagnosed with FAP and had a liver transplant, and 89 (44.5%) were non-carriers. Most were women (58.1%) and married (66.5%). The anxiety variable was assessed using the Zung Self-Rating Anxiety Scale (SAS). Results: The anxiety scores were higher for symptomatic carriers and for those who underwent psychological support consultations over the years. For symptomatic carriers, the mean scores were superior to 40 points, which reflects clinical anxiety. Conclusion: Although it was not possible to differentiate between the mid-and long-term psychological impacts, this study supports the conclusion that the proximity to the age of symptoms onset might be a trigger for anxiety.
MJD is the most frequent dominant ataxia and an incapacitating disorder. Onset is most frequently during the reproductive years, and genetic counseling is its only means of prevention. The causative mutation--an expansion of a (CAG)n on chromosome 14q32.1--can now be directly detected. We now report the first two cases of prenatal diagnosis (PND). The first presented as a simultaneous request for predictive testing and PND at 14 weeks of pregnancy. Owing to time constraints, we performed a full protocol of counseling with shorter inter between sessions, while psycho-social evaluation of the other parent obstetric consults were also begun. We ensured that the couple wished termination if the fetus was a carrier, to avoid a presymptomatic test for the unborn child. We were thus able to deliver test results two weeks before PND. As the fetus carried an expanded allele (77 CAGs) inherited from his father, termination was performed and the couple received counselling, psychological and social support. The second case was the fetus of a carrier-mother that was diagnosed as non-carrier, also after amniocentesis.
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