{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T05:16:50Z","timestamp":1788239810187,"version":"build-2803163510"},"reference-count":16,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T00:00:00Z","timestamp":1788220800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:p>Infantile hypercalcemia type 1 (HCINF1) is a rare genetic disorder caused by pathogenic variants in the CYP24A1 gene, which encodes the vitamin D\u2013catabolic enzyme 24-hydroxylase responsible for inactivating 1,25-dihydroxyvitamin D\u2083. The clinical presentation ranges from severe forms diagnosed in infancy\u2014characterized by hypercalcemia, dehydration, and vomiting\u2014to milder forms that are often identified in adulthood during evaluation for recurrent nephrolithiasis. We present two adult female patients with late-onset HCINF1, both initially referred to a nephrologist for nephrolithiasis and nephrocalcinosis, and one male patient with an infantile presentation who began fluconazole therapy in adulthood. This case series highlights rare late-onset manifestations of HCINF1 associated with recurrent nephrolithiasis, secondary distal renal tubular acidosis (dRTA), and variable degrees of renal function impairment. It emphasizes the importance of considering genetic testing in adults with unexplained hypercalcemia and nephrolithiasis and supports the therapeutic role of fluconazole in selected cases.<\/jats:p>","DOI":"10.3389\/fmed.2026.1925619","type":"journal-article","created":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T04:26:23Z","timestamp":1788236783000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Case Report: Infantile hypercalcemia type 1 due to CYP24A1 pathogenic variants\u2014three adult patients with nephrolithiasis and nephrocalcinosis successfully treated with fluconazole"],"prefix":"10.3389","volume":"13","author":[{"given":"Nikolina","family":"Vucenovic Basic","sequence":"first","affiliation":[{"name":"Department of Internal Medicine, General Hospital Sibenik","place":["Sibenik, Croatia"]},{"name":"Department of Internal Medicine, University Hospital Centre Zagreb","place":["Zagreb, Croatia"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bodo","family":"Beck","sequence":"additional","affiliation":[{"name":"Institute of Human Genetics, University Hospital Cologne","place":["Cologne, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annemarie","family":"Balasko","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, University Hospital Centre Zagreb","place":["Zagreb, Croatia"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ivana","family":"Vukovic Brinar","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, University Hospital Centre Zagreb","place":["Zagreb, Croatia"]},{"name":"School of Medicine, University of Zagreb","place":["Zagreb, Croatia"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Margareta","family":"Fistrek Prlic","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, University Hospital Centre Zagreb","place":["Zagreb, Croatia"]},{"name":"School of Medicine, University of Zagreb","place":["Zagreb, Croatia"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,1]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"F1243","DOI":"10.1152\/ajprenal.00211.2016","article-title":"Genetic, pathophysiological, and clinical aspects of nephrocalcinosis","volume":"311","author":"Oliveira","year":"2016","journal-title":"Am J Phys"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"55","DOI":"10.2214\/ajr.138.1.55","article-title":"Medullary nephrocalcinos 2 is: sonographic evaluation","volume":"138","author":"Glazer","year":"1982","journal-title":"Am J Roentgenol"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"F1337","DOI":"10.1152\/ajprenal.00273.2015","article-title":"Ways of calcium reabsorption in the kidney","volume":"310","author":"Moor","year":"2016","journal-title":"Am J 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