{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T22:06:26Z","timestamp":1776722786390,"version":"3.51.2"},"reference-count":15,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T00:00:00Z","timestamp":1773187200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Psychiatry"],"abstract":"<jats:p>Methylmalonic acidemia with homocystinuria (MMA-HC) is a rare inherited metabolic disorder characterized by diverse and nonspecific clinical manifestations. Here, we report the first case of MMA-HC presenting in the postpartum period, aiming to enhance clinicians\u2019 awareness and diagnostic capabilities regarding this condition. This will help prevent misdiagnosis and missed diagnosis, thereby enabling timely and effective treatment for patients. A 17-year-old woman who underwent cesarean section presented with encephalitis-like symptoms shortly after childbirth, including fever, headache, psychiatric disturbances, and limb weakness, accompanied by a progressive macrocytic anemia that worsened significantly from the late prenatal to the early postpartum period, along with markedly elevated red cell distribution width (RDW) and leukopenia and severe hyperhomocysteinemia. Genetic testing confirmed cblC-type MMA-HC. A metabolic crisis was triggered after administering valproate for seizures. The patient was effectively treated with a multidisciplinary approach, highlighting the importance of careful clinical monitoring and systematic metabolic screening in peripartum women presenting with progressive hematological abnormalities and encephalopathic symptoms. It further validates the critical role of early diagnosis and multidisciplinary comprehensive treatment in managing complex inherited metabolic disorders, thereby contributing to enhanced overall diagnostic and therapeutic standards.<\/jats:p>","DOI":"10.3389\/fpsyt.2026.1734901","type":"journal-article","created":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T11:49:31Z","timestamp":1773229771000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Encephalitis-like presentation of methylmalonic acidemia with homocystinuria in a postpartum woman: a case report"],"prefix":"10.3389","volume":"17","author":[{"given":"Qianqian","family":"Wang","sequence":"first","affiliation":[{"name":"Department of Neurology, Affiliated Hospital of Jining Medical University","place":["Jining, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhongmin","family":"Ji","sequence":"additional","affiliation":[{"name":"Department of Neurology, Affiliated Hospital of Jining Medical University","place":["Jining, China"]},{"name":"Clinical Medicine Department, Affiliated Hospital of Jining Medical University","place":["Jining, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuzhong","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Neurology, Affiliated Hospital of Jining Medical University","place":["Jining, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ziyou","family":"Qi","sequence":"additional","affiliation":[{"name":"Department of Neurology, Affiliated Hospital of Jining Medical University","place":["Jining, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,3,11]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1002\/jimd.12370","article-title":"Guidelines for the diagnosis and management of methylmalonic acidaemia and propionic acidaemia: First revision","volume":"44","author":"Forny","year":"2021","journal-title":"J Inherit Metab Dis"},{"key":"B2","doi-asserted-by":"publisher","first-page":"29","DOI":"10.5582\/irdr.2023.01016","article-title":"A regionally adapted HRM-based technique to screen MMACHC carriers for methylmalonic acidemia with homocystinuria in Shandong Province, China","volume":"12","author":"Yang","year":"2023","journal-title":"Intractable Rare Dis Res"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.3389\/fnut.2023.1124387","article-title":"Case report: An asymptomatic mother with an inborn error of cobalamin metabolism (cblC) detected through high homocysteine levels during prenatal diagnosis","volume":"10","author":"Liu","year":"2023","journal-title":"Front Nutr"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1007\/s10545-014-9802-8","article-title":"Methylmalonic acidemia (MMA) in pregnancy: a case series and literature review","volume":"38","author":"Raval","year":"2015","journal-title":"J Inherit Metab Dis"},{"key":"B5","doi-asserted-by":"publisher","first-page":"33","DOI":"10.1186\/s13023-022-02179-y","article-title":"Adult-onset CblC deficiency: a challenging diagnosis involving different adult clinical specialists","volume":"17","author":"Kalantari","year":"2022","journal-title":"Orphanet J Rare Dis"},{"key":"B6","doi-asserted-by":"publisher","first-page":"e1838","DOI":"10.1002\/mgg3.1838","article-title":"Prenatal diagnosis of combined methylmalonic acidemia and homocystinuria cobalamin C type using clinical exome sequencing and targeted gene analysis","volume":"9","author":"Hwang","year":"2021","journal-title":"Mol Genet Genomic Med"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1007\/s10545-011-9365-x","article-title":"Combined methylmalonic acidemia and homocystinuria, cblC type. 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Complications, pathophysiology, and outcomes","volume":"35","author":"Carrillo-Carrasco","year":"2012","journal-title":"J\u00a0Inherit Metab Dis"},{"key":"B8","doi-asserted-by":"publisher","first-page":"318","DOI":"10.1186\/s12884-019-2474-5","article-title":"Prospective evaluation of pregnancy outcome in an Italian woman with late-onset combined homocystinuria and methylmalonic aciduria","volume":"19","author":"Grandone","year":"2019","journal-title":"BMC Pregnancy Childbirth"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3390\/medicina57020128","article-title":"Dietary Treatment from Birth to Pregnancy in a Woman with Methylmalonic Aciduria","volume":"57","author":"Kowalik","year":"2021","journal-title":"Med (Kaunas)"},{"key":"B10","doi-asserted-by":"publisher","first-page":"306","DOI":"10.1186\/s13023-023-02890-4","article-title":"Late-onset cblC defect: clinical, biochemical and molecular analysis","volume":"18","author":"Ding","year":"2023","journal-title":"Orphanet J Rare Dis"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1002\/humu.21001","article-title":"Spectrum of mutations in MMACHC, allelic expression, and evidence for genotype-phenotype correlations","volume":"30","author":"Lerner-Ellis","year":"2009","journal-title":"Hum Mutat"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1016\/j.braindev.2014.06.007","article-title":"First Chinese case of successful pregnancy with combined methylmalonic aciduria and homocystinuria, cblC type","volume":"37","author":"Liu","year":"2015","journal-title":"Brain Dev"},{"key":"B13","doi-asserted-by":"publisher","first-page":"340","DOI":"10.1186\/s12882-024-03774-w","article-title":"Late-onset renal TMA and tubular injury in cobalamin C disease: a report of three cases and literature review","volume":"25","author":"Bao","year":"2024","journal-title":"BMC Nephrol"},{"key":"B14","doi-asserted-by":"publisher","first-page":"330","DOI":"10.1186\/s13023-022-02471-x","article-title":"Late-onset cblC deficiency around puberty: a retrospective study of the clinical characteristics, diagnosis, and treatment","volume":"17","author":"Chen","year":"2022","journal-title":"Orphanet J Rare Dis"},{"key":"B15","doi-asserted-by":"publisher","first-page":"20","DOI":"10.1186\/s13023-024-03021-3","article-title":"Late-onset methylmalonic acidemia and homocysteinemia (cblC disease): systematic review","volume":"19","author":"Arhip","year":"2024","journal-title":"Orphanet J Rare Dis"}],"container-title":["Frontiers in Psychiatry"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpsyt.2026.1734901\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T11:49:32Z","timestamp":1773229772000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpsyt.2026.1734901\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,11]]},"references-count":15,"alternative-id":["10.3389\/fpsyt.2026.1734901"],"URL":"https:\/\/doi.org\/10.3389\/fpsyt.2026.1734901","relation":{},"ISSN":["1664-0640"],"issn-type":[{"value":"1664-0640","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,11]]},"article-number":"1734901"}}