Young‐onset dementia diagnosis, management and care

In reply: We thank Bahlo1 for the response to our narrative review2 and agree that the developments in whole genome sequencing (WGS) justify increased use of this technique in determining genetic abnormalities in young‐onset dementia. The C9orf72 repeat expansion is the most important genetic cause of frontotemporal dementia.3

Although WGS is accredited for clinical use in many neurogenetic disorders, it is yet to be accredited by the National Association of Testing Authorities (NATA) for repeat disorders. Patients require separate genetic testing in these clinical situations, such as polymerase chain reaction (PCR) for CAG (cytosine, adenine, guanine) repeats in Huntington disease and repeat primed PCR for the C9orf72 expansion. Current barriers to the routine use of WGS include cost and the 100‐fold data generated, which require curation and analysis. There is a need for careful patient‐centred genetic counselling given the greater potential for uncertain and incidental findings. Of course, this technology also facilitates improved identification of a genetic diagnosis. Our team from Neuropsychiatry at the Royal Melbourne Hospital is currently working with the hospital's neurogenetics team to develop new models of care that seek to investigate and incorporate WGS in the clinic with genetic counselling. This service will provide more information about the real‐world utility of this important technology for individuals with young‐onset dementia. We would encourage further collaborations between clinicians and neurogenetics teams to examine the utility of WGS and ultimately make it more accessible for younger people with dementia and their families.