{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,27]],"date-time":"2025-08-27T15:40:05Z","timestamp":1756309205396,"version":"3.44.0"},"reference-count":19,"publisher":"BMJ","issue":"2","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2023,2,1]]},"published-print":{"date-parts":[[2023,2]]},"abstract":"<jats:p>A young man presented unconscious with severe hyponatraemia, hypokalaemia, hypomagnesaemia and metabolic alkalosis. After 4 months of treatment in hospital, the hypomagnesaemia persisted. The patient had no signs of diabetes mellitus, and radiology showed no abnormalities of the kidneys, pancreas or genitourinary tract. A parenteral magnesium load demonstrated renal wasting with increased fractional urinary excretion of magnesium. Genetic tests for Gitelman as well as Bartter syndromes were negative. However, a wider genetic panel revealed that the patient was heterozygous for a deletion on chromosome band 17q12, encompassing the whole HNF1B gene.<\/jats:p>\n               <jats:p>This case highlights the importance of considering pathogenic HNF1B variants in isolated profound hypomagnesaemia caused by renal wasting. Pathogenic HNF1B variants may partly mimic hypomagnesaemia found in Gitelman and Bartter syndromes and may be present without other features linked to HNF1B variants, including diabetes mellitus.<\/jats:p>","DOI":"10.1136\/bcr-2022-254274","type":"journal-article","created":{"date-parts":[[2023,2,9]],"date-time":"2023-02-09T10:05:48Z","timestamp":1675937148000},"page":"e254274","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":1,"title":["HNF1B variant without hyperglycaemia as a cause of isolated profound hypomagnesaemia"],"prefix":"10.1136","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7211-087X","authenticated-orcid":false,"given":"Shobitha","family":"Vollmer","sequence":"first","affiliation":[{"name":"Department of Endocrinology, Skane University Hospital, Lund, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Per","family":"Katzman","sequence":"additional","affiliation":[{"name":"Department of Endocrinology, Skane University Hospital, Lund, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Magnus","family":"Londahl","sequence":"additional","affiliation":[{"name":"Department of Endocrinology, Skane University Hospital, Lund, Sweden"},{"name":"Department of Clinical Sciences in Lund, Lund University, Lund, Sweden"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2023,2,9]]},"reference":[{"key":"2025082708205292000_16.2.e254274.1","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1186\/s40842-020-00103-6","article-title":"Maturity-onset diabetes of the young type 5 a multisystemic disease: a case report of a novel mutation in the HNF1B gene and literature review","volume":"6","author":"Mateus","year":"2020","journal-title":"Clin Diabetes Endocrinol"},{"key":"2025082708205292000_16.2.e254274.2","doi-asserted-by":"publisher","DOI":"10.1515\/jpem-2014-0384"},{"key":"2025082708205292000_16.2.e254274.3","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1210\/jc.2018-01696","article-title":"Frequency and characteristics of MODY 1 (HNF4A mutation) and MODY 5 (HNF1B mutation): analysis from the DPV database","volume":"104","author":"Warncke","year":"2019","journal-title":"J Clin Endocrinol Metab"},{"key":"2025082708205292000_16.2.e254274.4","doi-asserted-by":"publisher","DOI":"10.2337\/dc16-2462"},{"key":"2025082708205292000_16.2.e254274.5","doi-asserted-by":"crossref","first-page":"1325","DOI":"10.1007\/s00467-018-3990-7","article-title":"New insights into the role of HNF-1\u03b2 in kidney (patho) physiology","volume":"34","author":"Ferr\u00e8","year":"2019","journal-title":"Pediatr Nephrol"},{"key":"2025082708205292000_16.2.e254274.6","doi-asserted-by":"publisher","DOI":"10.1089\/thy.2017.0500"},{"key":"2025082708205292000_16.2.e254274.7","article-title":"MAGNESIUM deficiency in gastrointestinal fluid loss","volume":"306","author":"THOREN","year":"1963","journal-title":"Acta Chir Scand Suppl"},{"key":"2025082708205292000_16.2.e254274.8","doi-asserted-by":"crossref","first-page":"1123","DOI":"10.1007\/s00467-016-3416-3","article-title":"Genetic causes of hypomagnesemia, a clinical overview","volume":"32","author":"Viering","year":"2017","journal-title":"Pediatr Nephrol"},{"key":"2025082708205292000_16.2.e254274.9","doi-asserted-by":"publisher","DOI":"10.1001\/archinte.1984.00350210112019"},{"key":"2025082708205292000_16.2.e254274.10","first-page":"290","article-title":"Interrelationships of magnesium and potassium homeostasis","volume":"19","author":"Ryan","year":"1993","journal-title":"Miner Electrolyte Metab"},{"key":"2025082708205292000_16.2.e254274.11","doi-asserted-by":"crossref","first-page":"707","DOI":"10.1007\/s00467-015-3142-2","article-title":"HNF1B-associated clinical phenotypes: the kidney and beyond","volume":"31","author":"Bockenhauer","year":"2016","journal-title":"Pediatr Nephrol"},{"key":"2025082708205292000_16.2.e254274.12","doi-asserted-by":"publisher","DOI":"10.1681\/ASN.2008060633"},{"key":"2025082708205292000_16.2.e254274.13","doi-asserted-by":"publisher","DOI":"10.1159\/000439286"},{"key":"2025082708205292000_16.2.e254274.14","unstructured":"Pirahanchi Y , Jessu R , Aeddula NR . 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