Planned interventions
Participants in the control arm (GH +) will resume receiving their GH treatment at a dosing level determined by their clinical care team (following the minimum 6-week discontinuation period required prior to randomisation). Participants in the experimental arm (GH −) will not resume GH treatment. Both arms will be followed up at 6 monthly intervals until near FH or the 36-month follow-up (whichever is soonest).All currently available GH treatment preparations with the active ingredient Somatropin are allowed, as detailed in the British National Formulary for Children (BNFc) in the UK and Kindermedika in Austria (