{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T21:24:34Z","timestamp":1791494674878,"version":"4.3.4"},"reference-count":16,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,12,10]],"date-time":"2021-12-10T00:00:00Z","timestamp":1639094400000},"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><jats:bold>Background:<\/jats:bold> Ciliopathies are rare diseases causing renal and extrarenal manifestations. Here, we report the case of a ciliopathy induced by a homozygous pathogenic variant in the <jats:italic>TTC21B<\/jats:italic> gene.<\/jats:p><jats:p><jats:bold>Case Description:<\/jats:bold> A 47-year-old patient started hemodialysis for chronic kidney disease (CKD) of unknown origin. She presented with early onset of hypertension, pre-eclampsia, myopia and cirrhosis. Renal biopsy showed mild interstitial fibrosis, tubular atrophy, and moderate arteriosclerosis while liver pathology demonstrates grade B biliary cirrhosis. Family history revealed several cases of early-onset severe hypertension and one case of end-stage renal disease (ESRD) needing kidney transplantation at twenty years of age. Clinical exome sequencing showed homozygosis for the pathogenic variant c.626C&amp;gt;T (p.Pro209Leu) in the <jats:italic>TTC21B<\/jats:italic> gene. The patient underwent combined liver-renal transplantation with an excellent renal and hepatic graft outcome.<\/jats:p><jats:p><jats:bold>Conclusions:<\/jats:bold><jats:italic>TTC21B<\/jats:italic> gene mutations can lead heterogeneous to clinical manifestations and represent an underappreciated cause of ESRD. The paradigm in diagnosis of CKD of early onset and\/or of unknown origin is changing and genetic counseling should be performed in all patients and families that meet those criteria. Renal or combined liver-renal transplantation represents the best option for patients suffering from those diseases in terms of prognosis and quality of life.<\/jats:p>","DOI":"10.3389\/fmed.2021.795216","type":"journal-article","created":{"date-parts":[[2021,12,10]],"date-time":"2021-12-10T06:39:41Z","timestamp":1639118381000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":7,"title":["Case Report: Homozygous Pathogenic Variant P209L in the TTC21B Gene: A Rare Cause of End Stage Renal Disease and Biliary Cirrhosis Requiring Combined Liver-Kidney Transplantation. A Case Report and Literature Review"],"prefix":"10.3389","volume":"8","author":[{"given":"Giuseppe","family":"Gambino","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Concetta","family":"Catalano","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martina","family":"Marangoni","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Geers","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alain 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