{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T13:21:18Z","timestamp":1789046478778,"version":"build-2803163510"},"reference-count":13,"publisher":"BMJ","issue":"5","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2025,5,7]]},"published-print":{"date-parts":[[2025,5]]},"abstract":"<jats:p>Neonatal unconjugated hyperbilirubinaemia may have a multifactorial aetiology, and different conditions may act together to increase the risk of severe hyperbilirubinaemia and bilirubin-induced neurological dysfunction.<\/jats:p>\n               <jats:p>We report a novel case of severe neonatal unconjugated hyperbilirubinaemia requiring treatment with exchange transfusions in two premature twins with a similar clinical presentation. The aetiological investigation revealed glucose-6-phosphate dehydrogenase (G6PD) deficiency combined with heterozygosity for two variants in the <jats:italic>UGT1A1<\/jats:italic> gene. These two conditions alone are common genetic causes of neonatal hyperbilirubinaemia, but the co-occurrence of both in the same patient is unusual.<\/jats:p>\n               <jats:p>This case highlights a rare synergistic interaction between preterm birth, G6PD deficiency and <jats:italic>UGT1A1<\/jats:italic> variants in the development of a severe case of neonatal unconjugated hyperbilirubinaemia in the absence of identifiable haemolysis.<\/jats:p>","DOI":"10.1136\/bcr-2025-265558","type":"journal-article","created":{"date-parts":[[2025,5,21]],"date-time":"2025-05-21T05:45:18Z","timestamp":1747806318000},"page":"e265558","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":1,"title":["Severe neonatal hyperbilirubinaemia in preterm twins with glucose-6-phosphate dehydrogenase deficiency and <i>UGT1A1<\/i> gene variants"],"prefix":"10.1136","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1556-9737","authenticated-orcid":false,"given":"Mariana","family":"Cortez Ferreira","sequence":"first","affiliation":[{"name":"Neonatology Department, Maternidade Bissaya Barreto, Centro Hospitalar e Universitario de Coimbra EPE, Coimbra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jo\u00e3o Filipe","family":"Nico","sequence":"additional","affiliation":[{"name":"Neonatology Department, Maternidade Bissaya Barreto, Centro Hospitalar e Universitario de Coimbra EPE, Coimbra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jo\u00e3o Silva","family":"Gomes","sequence":"additional","affiliation":[{"name":"Clinical Haematology Department, Centro Hospitalar e Universit\u00e1rio de Coimbra EPE, Coimbra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana Lopes","family":"Dias","sequence":"additional","affiliation":[{"name":"Neonatology Department, Maternidade Bissaya Barreto, Centro Hospitalar e Universitario de Coimbra EPE, Coimbra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,5,21]]},"reference":[{"key":"2025082703230207000_18.5.e265558.1","doi-asserted-by":"publisher","DOI":"10.1016\/j.clp.2006.09.002"},{"key":"2025082703230207000_18.5.e265558.2","doi-asserted-by":"publisher","DOI":"10.1016\/j.siny.2009.10.007"},{"key":"2025082703230207000_18.5.e265558.3","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1016\/j.clp.2016.01.008","article-title":"The Preterm Infant: A High-Risk Situation for Neonatal Hyperbilirubinemia Due to Glucose-6-Phosphate Dehydrogenase Deficiency","volume":"43","author":"Kaplan","year":"2016","journal-title":"Clin 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