The patient then received treatment with teriflunomid (a dihydroorotate dehydrogenase inhibitor); 6 months after teriflunomid initiation, the patient presented with overt hyperthyroidism with undetectable serum TSH levels and with serum free T4 and free T3 levels at three times and 1.8 times the upper limit of normal, respectively. The gene discussed is DHODH; the disease is hyperthyroidism.