We report a case of rapidly changing serous retinal detachment (SRD) during melanoma therapy with a combination of encorafenib, a serine/threonine-protein kinase B-Raf (BRAF) inhibitor, and binimetinib, a mitogen-activated protein kinase (MEK) inhibitor. The gene discussed is WNK2; the disease is dopa-responsive dystonia due to sepiapterin reductase deficiency.