{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T23:03:37Z","timestamp":1790550217886,"version":"4.1.0"},"reference-count":18,"publisher":"American Academy of Pediatrics (AAP)","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2013,7,1]]},"abstract":"<jats:p>Cobalamin C (cblC) defect is the most common inborn error of vitamin B12 metabolism. Clinical features vary as does the severity of the disease. In most cases, the clinical symptoms of cblC defect tend to appear during infancy or early childhood as a multisystem disease with severe neurologic, ocular, hematologic, renal, and gastrointestinal signs. The neurologic findings are common and include hypotonia, developmental delay, microcephaly, seizures hydrocephalus, and brain MRI abnormalities. We report a case of a young boy with cblC defect, who did not undergo newborn screening, presenting at the age of 2 years with isolated pulmonary hypertension as the leading symptom. This novel way of presentation of cblC defect enlarges the spectrum of inherited diseases that must be considered in the differential diagnosis of pulmonary hypertension.<\/jats:p>","DOI":"10.1542\/peds.2012-1945","type":"journal-article","created":{"date-parts":[[2013,6,11]],"date-time":"2013-06-11T00:04:46Z","timestamp":1370909086000},"page":"e248-e251","source":"Crossref","is-referenced-by-count":34,"title":["Cobalamin C Defect Presenting With Isolated Pulmonary Hypertension"],"prefix":"10.1542","volume":"132","author":[{"given":"Francesca G.","family":"Iodice","sequence":"first","affiliation":[{"name":"Unit of Pediatric Cardiac Anesthesia and Intensive Care, Department of Pediatric Cardiology and Cardiac Surgery,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luca","family":"Di Chiara","sequence":"additional","affiliation":[{"name":"Unit of Pediatric Cardiac Anesthesia and Intensive Care, Department of Pediatric Cardiology and Cardiac Surgery,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Boenzi","sequence":"additional","affiliation":[{"name":"Division of Metabolic Diseases, Department of Pediatric Medicine,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chiara","family":"Aiello","sequence":"additional","affiliation":[{"name":"Unit of Neuromuscular Diseases, Department of Neurology, and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lidia","family":"Monti","sequence":"additional","affiliation":[{"name":"Department of Radiology, Children\u2019s Hospital Bambino Ges\u00f9 IRCCS, Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paola","family":"Cogo","sequence":"additional","affiliation":[{"name":"Unit of Pediatric Cardiac Anesthesia and Intensive Care, Department of Pediatric Cardiology and Cardiac Surgery,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlo","family":"Dionisi-Vici","sequence":"additional","affiliation":[{"name":"Division of Metabolic Diseases, Department of Pediatric Medicine,"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"417","published-online":{"date-parts":[[2013,7,1]]},"reference":[{"issue":"1","key":"2021120900112962900_B1","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1007\/s10545-010-9161-z","article-title":"Cobalamin C defect: natural history, pathophysiology, and treatment.","volume":"34","author":"Martinelli","year":"2011","journal-title":"J Inherit Metab Dis"},{"issue":"1","key":"2021120900112962900_B2","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1038\/ng1683","article-title":"Identification of the gene responsible for methylmalonic aciduria and homocystinuria, cblC type.","volume":"38","author":"Lerner-Ellis","year":"2006","journal-title":"Nat Genet"},{"issue":"4","key":"2021120900112962900_B3","doi-asserted-by":"crossref","first-page":"475","DOI":"10.1016\/j.ymgme.2007.11.005","article-title":"Spectrum of MMACHC mutations in Italian and Portuguese patients with combined methylmalonic aciduria and homocystinuria, cblC type.","volume":"93","author":"Nogueira","year":"2008","journal-title":"Mol Genet Metab"},{"issue":"4","key":"2021120900112962900_B4","doi-asserted-by":"crossref","first-page":"528","DOI":"10.1023\/A:1005353530303","article-title":"Clinical heterogeneity and prognosis in combined methylmalonic aciduria and homocystinuria (cblC).","volume":"20","author":"Rosenblatt","year":"1997","journal-title":"J Inherit Metab Dis"},{"issue":"1","key":"2021120900112962900_B5","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1007\/s10545-011-9364-y","article-title":"Combined methylmalonic acidemia and homocystinuria, cblC type. 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