Matthew J. Farrer

Recent studies show that pathogenic variants in DNAJC12 , a co‐chaperone for monoamine synthesis, may cause mild hyperphenylalaninemia with infantile dystonia, young‐onset parkinsonism, developmental delay and cognitive deficits. DNAJC12 has been included in newborn screening, most revealingly in Spain, and those results highlight the importance of genetic diagnosis and early intervention in combating human disease. However, practitioners may be unaware of these advances and it is probable that many patients, especially adults, have yet to receive molecular testing for DNAJC12 . Hence, this review summarizes genotype–phenotype relationships and treatment paradigms for patients with pathogenic variants in DNAJC12 . It provides an overview of the structure of DNAJC12 protein, known genetic variants, domains, and binding partners, and elaborates on its role in monoamine synthesis, disease etiology, and pathogenesis. © 2023 International Parkinson and Movement Disorder Society.