Background and importanceWilson disease is a rare autosomal recessive disorder. It is characterised by an excessive accumulation of copper in the body, mainly in the liver, brain and cornea, leading to different manifestations, in which neuropsychiatric and hepatic manifestations predominate. Therapeutic management is based on the use of copper chelating agents (D-penicillamine, trientine) and drugs that hinder the absorption of copper (zinc salts). Ammonium tetrathiomolybdate, an experimental treatment, has also been used for periods of 8 weeks in patients with a neurological presentation under compassionate use.Aim and objectivesTo evaluate the effectiveness and toxicity of ammonium tetrathiomolybdate in a patient with Wilson disease.Material and methodsA 42-year-old man was diagnosed with Wilson disease with neurological manifestations at 33 years of age, and increased transaminase levels and the presence of Kayser–Fleischer ring in both eyes. One mutation, c3359T> A(p.Leu1120*), was identified on exon 15 in the ATP7B gene. He was treated with trientine for 4 months with clinical worsening, replacing trientine with zinc sulphate and ammonium tetrathiomolybdate. At 7 weeks, the last drug was retired because of progressive worsening of liver function. Given the clinical situation, D-penicillamine was added to the basic treatment that, 6 months later, was suspended due to marked deterioration in neurological and functional conditions. Maintenance treatment with zinc sulphate was continued. In the following months, neurological symptoms progressively improved, maintaining liver function. Seven years later, due to neurological worsening, treatment was started again with ammonium tetrathiomolybdate 60 mg daily and 8 weeks later it was increased to 120 mg daily (20 mg between meals three times a day and 20 mg with each meal three times a day).ResultsAfter 15 months of treatment with ammonium tetrathiomolybdate combined with zinc sulphate, the patient experienced improvements in motor and cognitive–behavioural symptoms, and maintained normal haematological and hepatic function. Before starting treatment with ammonium tetrathiomolybdate, at the analytical level, we found: copper in urine 56 μg/24 hours, ceruloplasmin 2 mg/dL and copper in blood 34 μg/dL; after 8 weeks (with a dose of 60 mg/day) the values were 111 μg/24 hours, 2 mg/dL and 63 μg/dL, respectively, and currently the values are 44 μg/24 hours, 2 mg/dL and 16 μg/dL.Conclusion and relevanceIn our patient, ammonium tetrathiomolybdate was effective and well tolerated for a prolonged period. It could be an alternative in patients with neurological manifestations.References and/or acknowledgementsNo conflict of interest.