{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T19:02:41Z","timestamp":1790103761852,"version":"4.0.1"},"reference-count":14,"publisher":"BMJ","issue":"9","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,8,31]]},"published-print":{"date-parts":[[2026,9]]},"abstract":"<jats:p>\n                    Karyomegalic Interstitial Nephritis (KIN) is a rare hereditary cause of chronic kidney disease (CKD), resulting from autosomal recessive mutations in the\n                    <jats:italic>FAN1<\/jats:italic>\n                    gene. Renal biopsy typically reveals severe interstitial fibrosis, tubular injury and glomerulosclerosis. Early and accurate diagnosis can guide appropriate management. We present a middle-aged euglycaemic, normotensive female who underwent renal biopsy, which revealed tubular vacuolisation, patchy acute injury and enlarged, bizarre nuclei (karyomegaly) with occasional intranuclear cytoplasmic inclusions. Clinical exome sequencing confirmed a homozygous one-base-pair deletion in exon 9 of the\n                    <jats:italic>FAN1<\/jats:italic>\n                    gene, classified as pathogenic. The patient was managed conservatively and her renal function remained stable at 6-month follow-up.\n                  <\/jats:p>","DOI":"10.1136\/bcr-2025-269966","type":"journal-article","created":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T18:15:12Z","timestamp":1790100912000},"page":"e269966","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["FAN1 mutation and karyomegalic nephropathy in chronic kidney disease"],"prefix":"10.1136","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-3404-1200","authenticated-orcid":false,"given":"Vijay","family":"Jeyachandran","sequence":"first","affiliation":[{"name":"Nephrology, Datta Meghe Institute of Higher Education and Research Deemed to be University, Wardha, MH, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amit","family":"Pasari","sequence":"additional","affiliation":[{"name":"Nephrology, Datta Meghe Institute of Higher Education and Research Deemed to be University, Wardha, MH, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kapil","family":"Sejpal","sequence":"additional","affiliation":[{"name":"Nephrology, Datta Meghe Institute of Higher Education and Research Deemed to be University, Wardha, MH, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alok","family":"Sharma","sequence":"additional","affiliation":[{"name":"Renal Pathology and Electron Microscopy, Dr Lal PathLabs Limited, Rohini, Delhi, HR, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manish","family":"Balwani","sequence":"additional","affiliation":[{"name":"Nephrology, Saraswati Kidney Care Center, Nagpur, India"},{"name":"Department of Nephrology, Datta Meghe Institute of Higher Education and Research Deemed to be University, Wardha, MH, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2026,9,22]]},"reference":[{"key":"2026092211150684000_19.9.e269966.1","doi-asserted-by":"publisher","DOI":"10.1038\/ng.2347"},{"key":"2026092211150684000_19.9.e269966.2","doi-asserted-by":"publisher","DOI":"10.1053\/j.gastro.2015.05.056"},{"key":"2026092211150684000_19.9.e269966.3","doi-asserted-by":"publisher","DOI":"10.1126\/science.aad5634"},{"key":"2026092211150684000_19.9.e269966.4","doi-asserted-by":"crossref","first-page":"95","DOI":"10.3233\/JHD-200448","article-title":"FAN1, a DNA Repair Nuclease, as a Modifier of Repeat Expansion Disorders","volume":"10","author":"Deshmukh","year":"2021","journal-title":"J Huntingtons Dis"},{"key":"2026092211150684000_19.9.e269966.5","doi-asserted-by":"publisher","DOI":"10.1093\/hmg\/ddy375"},{"key":"2026092211150684000_19.9.e269966.6","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajhg.2020.05.012"},{"key":"2026092211150684000_19.9.e269966.7","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1016\/S0005-8165(76)80089-3","article-title":"A case of unexplained karyomegaly","volume":"157","author":"Sclare","year":"1976","journal-title":"Beitr Pathol"},{"key":"2026092211150684000_19.9.e269966.8","first-page":"54","article-title":"Systemic karyomegaly associated with chronic interstitial nephritis. A new disease entity?","volume":"12","author":"Mihatsch","year":"1979","journal-title":"Clin Nephrol"},{"key":"2026092211150684000_19.9.e269966.9","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1016\/j.humpath.2013.07.036","article-title":"Systemic karyomegaly with primary pulmonary presentation","volume":"45","author":"Tagliente","year":"2014","journal-title":"Hum Pathol"},{"key":"2026092211150684000_19.9.e269966.10","doi-asserted-by":"publisher","DOI":"10.1093\/ndt\/17.11.1914"},{"key":"2026092211150684000_19.9.e269966.11","doi-asserted-by":"crossref","DOI":"10.1097\/MD.0000000000003349","article-title":"Karyomegalic Interstitial Nephritis","volume":"95","author":"Isnard","year":"2016","journal-title":"Medicine (Baltimore)"},{"key":"2026092211150684000_19.9.e269966.12","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1186\/s12882-020-01762-4","article-title":"Case report: a 58 -year -old man with small kidneys and elevated liver enzymes","volume":"21","author":"Dash","year":"2020","journal-title":"BMC Nephrol"},{"key":"2026092211150684000_19.9.e269966.13","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1186\/s12882-020-01733-9","article-title":"Karyomegalic interstitial nephritis with a novel FAN1 gene mutation and concurrent ALECT2 amyloidosis","volume":"21","author":"Law","year":"2020","journal-title":"BMC Nephrol"},{"key":"2026092211150684000_19.9.e269966.14","doi-asserted-by":"crossref","first-page":"2207","DOI":"10.1016\/j.ekir.2021.05.010","article-title":"Recurrent FAN1 p.W707X Pathogenic Variant Originating Before ad 1800 Underlies High Frequency of Karyomegalic Interstitial Nephritis in South Pacific Islands","volume":"6","author":"Gueguen","year":"2021","journal-title":"Kidney Int Rep"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2025-269966","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T18:15:14Z","timestamp":1790100914000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2025-269966"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9]]},"references-count":14,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9,22]]},"published-print":{"date-parts":[[2026,9]]}},"alternative-id":["10.1136\/bcr-2025-269966"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2025-269966","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9]]}}}