{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,28]],"date-time":"2025-08-28T00:07:13Z","timestamp":1756339633372,"version":"3.44.0"},"reference-count":21,"publisher":"BMJ","issue":"5","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2021,4,11]]},"published-print":{"date-parts":[[2021,5]]},"abstract":"<jats:p>Pterin species participate in dopamine biosynthesis, and abnormal pteridine metabolism contributes to reduced dopamine. GTP cyclohydrolase 1 (GCH-1) deficiency, which triggers pteridine hypometabolism and normally develops in childhood, can mediate an adult-onset decrease in levodopa production and dopa-responsive dystonia (DRD), with normal dopamine transporter single-photon emission computed tomography (DAT-SPECT). A recent study described normal DAT-SPECT in adult-onset cases with GCH-1 mutations, clinically diagnosed with Parkinson\u2019s disease, which raises the possibility that the abnormal metabolism of pteridine may be a differential diagnosis for adult-onset parkinsonism. We report an older patient with levodopa-responsive parkinsonism with normal DAT-SPECT, or scans without evidence of dopamine deficit (SWEDD), whose biochemical analysis showed pterin hypometabolism, which occurs in GCH-1-deficient DRD. Surprisingly, this patient presented no dystonia or GCH-1 gene mutation or deletion. This case suggests that low pterin metabolism should be considered in older-onset levodopa-responsive parkinsonism with normal DAT-SPECT, even without GCH-1 mutations or deletions.<\/jats:p>","DOI":"10.1136\/bcr-2020-240067","type":"journal-article","created":{"date-parts":[[2021,5,7]],"date-time":"2021-05-07T11:50:07Z","timestamp":1620388207000},"page":"e240067","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Older-onset levodopa-responsive parkinsonism with normal DAT-SPECT and pterin hypometabolism"],"prefix":"10.1136","volume":"14","author":[{"given":"Kazuyuki","family":"Togo","sequence":"first","affiliation":[{"name":"Department of Neurology, National Hospital Organization Utano National Hospital, Kyoto, Japan"},{"name":"Neurology, Osaka University Graduate School of Medicine, Suita, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Toshiya","family":"Ishihara","sequence":"additional","affiliation":[{"name":"Department of Neurology, National Hospital Organization Utano National Hospital, Kyoto, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1240-6369","authenticated-orcid":false,"given":"Kenji","family":"Yamamoto","sequence":"additional","affiliation":[{"name":"Department of Neurology, National Hospital Organization Utano National Hospital, Kyoto, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hideyuki","family":"Sawada","sequence":"additional","affiliation":[{"name":"Department of Neurology, National Hospital Organization Utano National Hospital, Kyoto, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2021,5,7]]},"reference":[{"key":"2025082713071107000_14.5.e240067.1","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2019.22360"},{"key":"2025082713071107000_14.5.e240067.2","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(14)61393-3"},{"key":"2025082713071107000_14.5.e240067.3","doi-asserted-by":"publisher","DOI":"10.1002\/mds.26424"},{"key":"2025082713071107000_14.5.e240067.4","doi-asserted-by":"publisher","DOI":"10.1136\/jnnp-2014-310256"},{"key":"2025082713071107000_14.5.e240067.5","doi-asserted-by":"publisher","DOI":"10.1007\/s00415-014-7477-6"},{"key":"2025082713071107000_14.5.e240067.6","unstructured":"Furukawa Y . GTP cyclohydrolase 1-deficient dopa-responsive dystonia. In: Adam MP , Ardinger HH , Pagon RA , eds. GeneReviews. Seattle, WA: University of Washington, 1993."},{"key":"2025082713071107000_14.5.e240067.7","doi-asserted-by":"crossref","first-page":"533","DOI":"10.1021\/cn4001928","article-title":"Simultaneous determination of all forms of biopterin and neopterin in cerebrospinal fluid","volume":"5","author":"Guibal","year":"2014","journal-title":"ACS Chem Neurosci"},{"key":"2025082713071107000_14.5.e240067.8","first-page":"5","article-title":"[Biopterin and child neurologic disease]","volume":"41","author":"Shintaku","year":"2009","journal-title":"No To Hattatsu"},{"key":"2025082713071107000_14.5.e240067.9","doi-asserted-by":"publisher","DOI":"10.1016\/S1474-4422(11)70141-7"},{"key":"2025082713071107000_14.5.e240067.10","doi-asserted-by":"crossref","first-page":"1860","DOI":"10.1007\/s00415-018-8930-8","article-title":"Gch1 mutations in dopa-responsive dystonia and Parkinson's disease","volume":"265","author":"Yoshino","year":"2018","journal-title":"J Neurol"},{"key":"2025082713071107000_14.5.e240067.11","doi-asserted-by":"publisher","DOI":"10.1001\/archneurol.2012.574"},{"key":"2025082713071107000_14.5.e240067.12","unstructured":"Hyland K . 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