{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T16:34:30Z","timestamp":1773160470174,"version":"3.50.1"},"reference-count":9,"publisher":"BMJ","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Reports"],"accepted":{"date-parts":[[2016,4,25]]},"abstract":"<jats:p>Pseudohypoparathyroidism type 1B (PHP1B) consists of a heterogeneous group of disorders characterised by resistance to parathyroid hormone (PTH). There are several different PHP1B subtypes that are all associated with methylation changes at<jats:italic>GNAS.<\/jats:italic>These epigenetic changes are caused by maternal deletions in<jats:italic>GNAS<\/jats:italic>or<jats:italic>STX16<\/jats:italic>, by paternal uniparental isodisomy of chromosome 20q (patUPD20q) or by undefined genetic mutations. The<jats:italic>GNAS<\/jats:italic>methylation changes are ultimately responsible for resistance to PTH signalling in the proximal renal tubules. However, there is no PTH resistance in the distal renal tubules nor in bone cells; consequently, patients with PHP1B have reduced urinary calcium excretion and can readily mobilise calcium (and phosphate) from the skeleton. We report a case of a sporadic PHP1B patient with broad<jats:italic>GNAS<\/jats:italic>methylation changes that were presumably caused by an unknown genetic mutation outside the<jats:italic>GNAS<\/jats:italic>locus. PTH resistance was preceded by several years by autoimmune negative hypothyroidism. Treatment consisted of calcium substitution and calcitriol.<\/jats:p>","DOI":"10.1136\/bcr-2016-214673","type":"journal-article","created":{"date-parts":[[2016,5,11]],"date-time":"2016-05-11T09:02:33Z","timestamp":1462957353000},"page":"bcr2016214673","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":6,"title":["Pseudohypoparathyroidism type 1B caused by methylation changes at the<i>GNAS<\/i>complex locus"],"prefix":"10.1136","volume":"2016","author":[{"given":"Sabrina","family":"Poradosu","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bert","family":"Bravenboer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rieko","family":"Takatani","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Harald","family":"J\u00fcppner","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2016,5,11]]},"reference":[{"key":"2025042703233256000_2016.may11_1.bcr2016214673.1","doi-asserted-by":"publisher","DOI":"10.1055\/s-0032-1314842"},{"key":"2025042703233256000_2016.may11_1.bcr2016214673.2","doi-asserted-by":"publisher","DOI":"10.1007\/978-0-387-77576-0_3"},{"key":"2025042703233256000_2016.may11_1.bcr2016214673.3","doi-asserted-by":"publisher","DOI":"10.1002\/jbmr.2408"},{"key":"2025042703233256000_2016.may11_1.bcr2016214673.4","doi-asserted-by":"publisher","DOI":"10.1542\/peds.2014-2806"},{"key":"2025042703233256000_2016.may11_1.bcr2016214673.5","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2006-2287"},{"key":"2025042703233256000_2016.may11_1.bcr2016214673.6","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2007-0927"},{"key":"2025042703233256000_2016.may11_1.bcr2016214673.7","doi-asserted-by":"publisher","DOI":"10.1210\/jc.2009-0176"},{"key":"2025042703233256000_2016.may11_1.bcr2016214673.8","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMc1508520"},{"key":"2025042703233256000_2016.may11_1.bcr2016214673.9","doi-asserted-by":"publisher","DOI":"10.1136\/jmg.2010.081356"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2016-214673","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,27]],"date-time":"2025-04-27T10:23:39Z","timestamp":1745749419000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2016-214673"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,5,11]]},"references-count":9,"alternative-id":["10.1136\/bcr-2016-214673"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2016-214673","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,5,11]]}}}