{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T10:44:54Z","timestamp":1782297894589,"version":"3.54.5"},"reference-count":8,"publisher":"BMJ","issue":"1","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2025,1,9]]},"published-print":{"date-parts":[[2025,1]]},"abstract":"<jats:p>We present the case of a toddler displaying neuroregression post-acute gastroenteritis, initially suggesting neurodegenerative disorders. Further investigations showed atypical results\u2014neuroimaging was inconsistent with suspected disorders, while fundus evaluation, evoked potentials and nerve conduction velocity were normal. Specialised tests using gas chromatography mass spectrometry and tandem mass spectrometry identified methylmalonic acidaemia (MMA), implicating abnormal neurometabolism. Early diagnosis and comprehensive treatment are essential. A low-protein diet suitable for MMA along with a syrup containing vitamin B12 and levocarnitine were prescribed. Notable developmental improvements were seen after 18 days of hospitalisation and up to 36 months of age, with no further regression. To date, only one case of MMA mimicking Rett syndrome, an atypical neurodegenerative variant, has been reported. This case highlights the diagnostic complexity of MMA, particularly when it mimics neurodegenerative disorders.<\/jats:p>","DOI":"10.1136\/bcr-2024-262804","type":"journal-article","created":{"date-parts":[[2025,1,23]],"date-time":"2025-01-23T21:20:13Z","timestamp":1737667213000},"page":"e262804","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":2,"title":["Methylmalonic acidaemia masquerading as a neurodegenerative disorder"],"prefix":"10.1136","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-1272-3076","authenticated-orcid":false,"given":"Nikita","family":"Diwan","sequence":"first","affiliation":[{"name":"Paediatrics, King George's Medical College, Lucknow, Uttar Pradesh, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0805-7370","authenticated-orcid":false,"given":"Shalini","family":"Tripathi","sequence":"additional","affiliation":[{"name":"Paediatrics, King George's Medical College, Lucknow, Uttar Pradesh, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mala","family":"Kumar","sequence":"additional","affiliation":[{"name":"Paediatrics, King George's Medical College, Lucknow, Uttar Pradesh, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,1,23]]},"reference":[{"key":"2025082700083652000_18.1.e262804.1","first-page":"e170","article-title":"Child Neurology: Krabbe disease: a potentially treatable white matter disorder","volume":"79","author":"Gelinas","year":"2012","journal-title":"Neurology (ECronicon)"},{"key":"2025082700083652000_18.1.e262804.2","article-title":"Infantile Metachromatic Leukodystrophy (MLD): A Rare Case","volume":"14","author":"Gajbhiye","year":"2022","journal-title":"Cureus"},{"key":"2025082700083652000_18.1.e262804.3","doi-asserted-by":"publisher","DOI":"10.4103\/0972-2327.112500"},{"key":"2025082700083652000_18.1.e262804.4","doi-asserted-by":"crossref","first-page":"73","DOI":"10.5582\/irdr.2018.01026","article-title":"Methylmalonic acidemia: Current status and research priorities","volume":"7","author":"Zhou","year":"2018","journal-title":"IRDR"},{"key":"2025082700083652000_18.1.e262804.5","first-page":"336","article-title":"Clinical analysis of organic acidemia in neonates from neonatal intensive care units","volume":"14","author":"Xu","year":"2012","journal-title":"Zhongguo Dang Dai Er Ke Za Zhi"},{"key":"2025082700083652000_18.1.e262804.6","doi-asserted-by":"crossref","DOI":"10.1186\/1750-1172-7-9","article-title":"Clinical and neurocognitive outcome in symptomatic isovaleric acidemia","volume":"7","author":"Gr\u00fcnert","year":"2012","journal-title":"Orphanet J Rare Dis"},{"key":"2025082700083652000_18.1.e262804.7","doi-asserted-by":"crossref","DOI":"10.1186\/s13023-014-0130-8","article-title":"Proposed guidelines for the diagnosis and management of methylmalonic and propionic acidemia","volume":"9","author":"Baumgartner","year":"2014","journal-title":"Orphanet J Rare Dis"},{"key":"2025082700083652000_18.1.e262804.8","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1177\/02537176231159916","article-title":"Methylmalonic Acidemia Masquerading as Rett Syndrome: An Atypical \u201cNeurodegenerative\u201d Variant?","volume":"45","author":"Jayaram","year":"2023","journal-title":"Indian J Psychol Med"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2024-262804","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,27]],"date-time":"2025-08-27T07:08:42Z","timestamp":1756278522000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2024-262804"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,1]]},"references-count":8,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,1,23]]},"published-print":{"date-parts":[[2025,1]]}},"alternative-id":["10.1136\/bcr-2024-262804"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2024-262804","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,1]]}}}