Knowledge and Attitudes Toward Genetic Testing in Parkinson’s Disease Dana Lundberg 2006

Parkinson’s Disease Is a degenerative neurological disorder Affects the substantia nigra, the part of the brain that controls movement Includes three symptoms:  a resting tremor  rigidity  bradykinesia (slowness) Substantia Nigra y/imagepages/19515.htm

Parkinson’s disease is divided into two onset categories:  Young-onset (less than 50 years at onset)  Old-onset (50 years or older at onset) Onset Categories

Objectives To identify attitudes Parkinson’s disease patients have toward diagnostic, predictive, and prenatal genetic testing To identify the resources most used by patients for information on Parkinson’s disease To assess the level of knowledge patients have about the genetics of Parkinson’s disease

Genetics of Parkinson’s Studies by Healy et al. (2004), Toft et al. (2005), and Hattori et al. (2004) revealed several gene mutations Genes that mutations have been identified in: - parkin - PINK1 - DJ-1 - α-Synuclein - LRKK2 Clinical genetic testing for the parkin and PINK1 genes is available

Rationale Prior to wide spread use of genetic testing for Parkinson’s disease researchers need to be aware of:  The interest level in genetic testing  The level of knowledge patients have of genetic testing  Where to target educational programs for genetic testing

Jacobs et al. showed attitudes toward genetic testing in a young-onset Parkinson’s population:  72% of subjects indicated that they would take a presymptomatic genetic test  57% were interested in the availability of a prenatal genetic test for Parkinson’s My study differs:  It included both young and old-onset patients  It included questions regarding sources of information and knowledge about the genetics of Parkinson’s Background

Hypothesis Patients with Parkinson’s disease will respond with a positive attitude toward diagnostic, predictive, and prenatal genetic testing for the disease.

Struthers Parkinson’s Center (n = 58) National Parkinson Foundation’s Young-Onset Conference in Phoenix, AZ (n = 39) Struthers Parkinson’s Center (Golden Valley, MN) Young-Onset Parkinson’s Conference (Phoenix, AZ) Survey Sites

Survey Demographics General knowledge about:  Parkinson’s disease  genetics  genetics of Parkinson’s disease Sources of information on Parkinson’s disease Attitudes toward:  diagnostic genetic testing  predictive genetic testing  prenatal genetic testing  genetic testing at 100%, 90%, and 60% genetic risk

Data Analysis Data were tabulated in an Excel spreadsheet Data were analyzed using descriptive and nonlinear (chi-squared) statistics P-values were considered significant when p ≤ 0.050

Distribution of Age of Onset

Distribution of Gender

Education Levels of Subject Population 19% 16% 65%

Distribution of Subjects with Relatives Diagnosed with Parkinson’s 79% 21%

Sources of Information P<0.001

Sources of Information P<0.001

Sources of Information P<0.001

Sources of Information P=0.040

Knowledge about Parkinson's and genetics: Number answering correctly (%) Knowledge Questions: < 50 years at onset n (%) ≥ 50 years at onset n (%) Total (%)p-value Parkinson's Disease Knowledge Questions: Parkinson’s disease is less common in people who smoke. 16 (35%)10 (20%)27%p = Parkinson’s disease always begins after age (98%)46 (90%)94%p = Parkinson’s disease is caused by a problem in brain cells that use dopamine. 44 (96%)44 (86%)91%p = There is a gene therapy treatment that can cure Parkinson’s disease. 45 (98%)47 (92%)95%p = There is an over-the counter, “natural” treatment that can cure Parkinson’s disease. 46 (100%)48 (94%)97%p = Specific Genetic Questions: A gene is composed of a group of proteins. 9 (20%)4 (8%)13%p = Genetic diseases always begin in childhood. 39 (85%)40 (78%)81%p = It is possible to have an abnormal gene without having symptoms of a disease.43 (93%)39 (76%)85%p = The Genetics of Parkinson's Disease Questions: Parkinson’s disease can be caused by a mutation in a gene called parkin.16 (35%)4 (8%)21%p < Scientists have identified genes that are associated with a higher risk of Parkinson’s disease.30 (65%)19 (37%)51%p = There is a gene test that can identify who will get Parkinson’s disease. 9 (20%)16 (31%)26%p = 0.180

Knowledge about Parkinson's and genetics: Number answering correctly (%) Knowledge Questions: < 50 years at onset n (%) ≥ 50 years at onset n (%) Total (%)p-value Parkinson's Disease Knowledge Questions: Parkinson’s disease is less common in people who smoke. 16 (35%)10 (20%)27%p = Parkinson’s disease always begins after age (98%)46 (90%)94%p = Parkinson’s disease is caused by a problem in brain cells that use dopamine. 44 (96%)44 (86%)91%p = There is a gene therapy treatment that can cure Parkinson’s disease. 45 (98%)47 (92%)95%p = There is an over-the counter, “natural” treatment that can cure Parkinson’s disease. 46 (100%)48 (94%)97%p = Specific Genetic Questions: A gene is composed of a group of proteins. 9 (20%)4 (8%)13%p = Genetic diseases always begin in childhood. 39 (85%)40 (78%)81%p = It is possible to have an abnormal gene without having symptoms of a disease.43 (93%)39 (76%)85%p = The Genetics of Parkinson's Disease Questions: Parkinson’s disease can be caused by a mutation in a gene called parkin.16 (35%)4 (8%)21%p < Scientists have identified genes that are associated with a higher risk of Parkinson’s disease.30 (65%)19 (37%)51%p = There is a gene test that can identify who will get Parkinson’s disease. 9 (20%)16 (31%)26%p = 0.180

Knowledge about Parkinson's and genetics: Number answering correctly (%) Knowledge Questions: < 50 years at onset n (%) ≥ 50 years at onset n (%) Total (%)p-value Parkinson's Disease Knowledge Questions: Parkinson’s disease is less common in people who smoke. 16 (35%)10 (20%)27%p = Parkinson’s disease always begins after age (98%)46 (90%)94%p = Parkinson’s disease is caused by a problem in brain cells that use dopamine. 44 (96%)44 (86%)91%p = There is a gene therapy treatment that can cure Parkinson’s disease. 45 (98%)47 (92%)95%p = There is an over-the counter, “natural” treatment that can cure Parkinson’s disease. 46 (100%)48 (94%)97%p = Specific Genetic Questions: A gene is composed of a group of proteins. 9 (20%)4 (8%)13%p = Genetic diseases always begin in childhood. 39 (85%)40 (78%)81%p = It is possible to have an abnormal gene without having symptoms of a disease.43 (93%)39 (76%)85%p = The Genetics of Parkinson's Disease Questions: Parkinson’s disease can be caused by a mutation in a gene called parkin.16 (35%)4 (8%)21%p < Scientists have identified genes that are associated with a higher risk of Parkinson’s disease.30 (65%)19 (37%)51%p = There is a gene test that can identify who will get Parkinson’s disease. 9 (20%)16 (31%)26%p = 0.180

Attitudes toward Genetic Testing: Number answering "yes" (%) Questions < 50 years at onset n (%) ≥ 50 years at onset n (%) Total (%)p-value Diagnostic Genetic Testing: Would you take this test? 100% genetic risk33 (72%)44 (86%)79%p = % genetic risk 33 (72%)41 (80%)76%p = % genetic risk23 (50%)34 (67%)59%p = Predictive Genetic Testing: Do you think this genetic test should be offered to people without symptoms of Parkinson’s disease? 100% genetic risk36 (78%)34 (67%)72%p = % genetic risk32 (70%)25 (49%)59%p = % genetic risk 26 (57%)25 (49%)53%p = Prenatal Genetic Testing: Do you think a prenatal genetic test should be offered to pregnant mothers? 100% genetic risk23 (50%) 17 (33%)41%p = % genetic risk23 (50%)15 (29%)39%p = % genetic risk21 (46%)13 (25%)35%p = 0.050

Attitudes toward Genetic Testing: Number answering "yes" (%) Questions < 50 years at onset n (%) ≥ 50 years at onset n (%) Total (%)p-value Diagnostic Genetic Testing: Would you take this test? 100% genetic risk33 (72%)44 (86%)79%p = % genetic risk 33 (72%)41 (80%)76%p = % genetic risk23 (50%)34 (67%)59%p = Predictive Genetic Testing: Do you think this genetic test should be offered to people without symptoms of Parkinson’s disease? 100% genetic risk36 (78%)34 (67%)72%p = % genetic risk32 (70%)25 (49%)59%p = % genetic risk 26 (57%)25 (49%)53%p = Prenatal Genetic Testing: Do you think a prenatal genetic test should be offered to pregnant mothers? 100% genetic risk23 (50%) 17 (33%)41%p = % genetic risk23 (50%)15 (29%)39%p = % genetic risk21 (46%)13 (25%)35%p = 0.050

Attitudes toward Genetic Testing: Number answering "yes" (%) Questions < 50 years at onset n (%) ≥ 50 years at onset n (%) Total (%)p-value Diagnostic Genetic Testing: Would you take this test? 100% genetic risk33 (72%)44 (86%)79%p = % genetic risk 33 (72%)41 (80%)76%p = % genetic risk23 (50%)34 (67%)59%p = Predictive Genetic Testing: Do you think this genetic test should be offered to people without symptoms of Parkinson’s disease? 100% genetic risk36 (78%)34 (67%)72%p = % genetic risk32 (70%)25 (49%)59%p = % genetic risk 26 (57%)25 (49%)53%p = Prenatal Genetic Testing: Do you think a prenatal genetic test should be offered to pregnant mothers? 100% genetic risk23 (50%) 17 (33%)41%p = % genetic risk23 (50%)15 (29%)39%p = % genetic risk21 (46%)13 (25%)35%p = 0.050

Discussion  Overall the attitudes expressed towards diagnostic, predictive, and prenatal genetic testing were positive 1.A majority (≥ 50%) of patients expressed positive attitudes toward diagnostic genetic testing at all three levels of genetic risk 2.Young-onset patients expressed positive attitudes toward predictive genetic testing slightly more, but not significantly more, than old-onset patients at all three levels of genetic risk 3.Young-onset patients expressed positive attitudes toward prenatal genetic testing significantly more than old-onset at the 90% and 60% levels of genetic risk (p = for both tests)

 Most commonly used source of information was a neurologist  Young-onset subjects used the internet significantly more than old-onset (p < 0.001)  Young-onset subjects used lay organizations and support groups/conferences significantly more than the old-onset subjects (p < for both resources)  a majority of the young-onset subjects were interviewed at a National Parkinson Foundation conference  Young-onset subjects were significantly more knowledgeable about the genetics of Parkinson’s (p < and p = 0.005)  Number of patients that correctly answered questions in both the young-onset and, especially, the old-onset groups was low Discussion

Applications Educational programmers:  What aspects of Parkinson’s and genetics to focus programs  Where to publish information to best educate the Parkinson’s community about genetic testing Pharmaceutical companies:  What populations to target for genetic testing  At what levels of genetic risk patients may be interested in taking genetic tests

Future Work Larger subject population through a mailed survey Redesign survey to include reasons for accepting or rejecting genetic testing Conduct at a conference oriented toward old-onset or both onset groups

Acknowledgements Dr. Martha Nance Catherine Wielinski Ms. Fruen Research Team

Knowledge and Attitudes Toward Genetic Testing in Parkinson’s Disease Dana Lundberg 2006