Prospective Pilot Trial to Address Feasibility and Safety of Oral Zinc in GNAO1 Associated Disorders

In this single arm trial, all participants will be receive the trial drug zinc acetate dihydrate orally. The Investigational medicinal product (IMP) will be given one hour after meal in a dosage which is recommended in Wilson Disease and has been given in this condition without observing severe adverse effects. If oral administration is not possible due to the disability level of the patient, the IMP can be mortared and suspended and can then be given as suspension orally or via the Percutaneous endoscopic gastrostomy. The total treatment duration in each patient is 6 months with stable dosage over the duration of the trial. If the therapy shows effects, the parents and participants may continue medication after the end of the trial. If not, they will stop the medication after the last visit at the trial site.