When the diagnosis is both clinically and genetically homogenous (e.g. Cystic Fibrosis and the CFTR gene), sequencing the single causative gene may be undertaken. Whilst WES/WGS and tests are covered by the new Medicare item number, to date most single gene tests are non‐rebatable and should be discussed with or referred to the local genetics services. Here, CFTR is linked to cystic fibrosis.