Pre-test information |
Family history (neurological/psychiatric examination, DNA data, pathology) |
Four ranges of repeat sizes |
Chance of unexpected test results |
Uncertainties about risk of expansion of intermediate alleles and penetrance of disease alleles with reduced penetrance |
Difference of intermediate test result for sons and daughters |
Chance of additional investigation of the unaffected parent without a family history for interpretation of the intermediate or reduced penetrance allele found in the applicant |
Exploration of the wish to know an intermediate or reduced penetrance allele test result |
Disclosure of repeat size if CAG repeat size is between 27 and 39 |
Offering the possibility of information and predictive testing to relatives of carriers with repeats between 27 and 39 (after adjusting to the awareness of what it means to be at risk) |
Discussing the possibility of prenatal testing with carriers with repeats between 27 and 39 because of the as yet unknown risk of expansion and penetrance |
Psychological support in decision making, before and after testing for applicant and relatives if they so wish |