Interest in genetic testing in pallido-ponto-nigral degeneration (PPND): a family with frontotemporal dementia with Parkinsonism linked to chromosome 17.

The specific mutation on the tau gene responsible for a neurodegenerative disease known as pallido-ponto-nigral degeneration (PPND) was recently located. PPND family members are at risk for an autosomal dominant form of frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17). This study investigated whether individuals in this family would consider presymptomatic genetic testing. Surveys were sent to 66 at-risk individuals in the family; replies were received from 20 (30%). Family members were asked if they would consider having testing now or in the future, and to indicate their reasons for and against proceeding with testing. Fifty per cent (n=10) of those who were at risk and who responded indicated they would consider testing now, and 55% (n=11) would think about it in the future. The most frequently cited reasons to proceed with testing were to 'collaborate with research' (70%) and to 'know if my children are at risk' (45%). The most frequently cited reason not to pursue testing was 'I can enjoy my life more fully by not knowing' (50%). Results suggest that interest in determining whether they will manifest PPND is generally low among at-risk members of this family, despite wide support and participation in other research studies.