Developing a consensus protocol for genetic testing in frontotemporal dementia

Background Frontotemporal dementia (FTD) is genetic in around 30% of people. The aim of the study was to develop a consensus protocol for genetic testing in FTD. Methods A Delphi methodology was used to achieve consensus recommendations from an international consortium of FTD and neurogenetics specialists. Participants were presented with a number of scenarios involving an asymptomatic individual from a family with a history of FTD but no known genetic mutation, who is requesting predictive testing. Consensus was defined as a recommendation being selected by >80% of respondents. Results 1) If an affected relative is alive and able to consent for diagnostic testing, a sample should be taken to ascertain whether there is a genetic form of FTD in the family before the asymptomatic individual can pursue predictive testing. 2) In the case where the affected relative is alive but unable to consent to diagnostic testing, experts decided that a blood or saliva sample could be taken if possible, and with the family’s agreement diagnostic testing could be performed to ascertain whether a mutation is present prior to predictive testing. 3) When there is no living affected relative but a sample of DNA or tissue has been stored, experts agreed that diagnostic testing should be performed on the sample, independent of family history, prior to offering predictive testing. 4) In the case where there is no living relative and no stored DNA or tissue but there is known pathology in a deceased family member that is pathognomonic for a specific genetic form of FTD, the consensus was to perform predictive testing based on that pathology. 5) Where there is no stored sample available, experts were in agreement that predictive testing should not be offered. Conclusions This revised protocol will provide guidance to clinicians for FTD‐specific genetic testing.