Abstract: SA-PO607
Unraveling Rarity: Atypical Presentation of Polycystic Kidney Disease
Session Information
- Cystic Kidney Diseases: Genetic Causes, Modifiers, and Extrarenal Manifestations
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1201 Genetic Diseases of the Kidneys: Cystic
Authors
- Lowe, Jessica Elise, Houston Methodist Hospital, Houston, Texas, United States
- Edwards, Angelina, Houston Methodist Hospital, Houston, Texas, United States
Introduction
Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder commonly associated with mutations in PDK1 and PDK2 and presents with enlarged kidneys seen on imaging due to cyst formation, typically classified by the Mayo Clinic Imaging Classification. However, genetic testing increasingly identifies other pathogenic variants leading to a spectrum of ADPKD. We present a case of an individual with poorly controlled hypertension and bilateral renal cysts whose imaging was not concordant with ADPKD but ultimately was positive based on genetic testing.
Case Description
A 73-year-old Caucasian woman with history of resistant hypertension presented for evaluation of elevated serum creatinine. One year prior, a CT scan performed for evaluation of abdominal pain showed incidental bilateral renal cysts. She was referred to Urology for further evaluation and underwent drainage of an 8 cm right renal cyst, without significant improvement in blood pressure control or abdominal pain. She then presented to nephrology clinic for referral for elevated creatinine and concern for chronic kidney disease. Laboratory testing revealed creatinine 1.51 mg/dL, blood urea nitrogen 31 mg/dL, and no proteinuria. Given the atypical cysts, genetic testing was pursued. Results confirmed pathogenic variant in the IFT140 gene, a rare cause of atypical ADPKD.
Discussion
Biallelic mutations in IFT140 are known to cause Mainzer-Saldino syndrome, a severe ciliopathy that causes skeletal and kidney abnormalities including cysts. However, monoallelic IFT140 loss of function variants have been emerging as a cause of atypical ADPKD beyond PKD1/PKD2, associated with large renal cysts, mild renal insufficiency, few liver cysts, and unknown extra-renal manifestations. This case highlights the critical role of genetic testing, particularly when imaging is equivocal, and may help with in widening the group of atypcial ADPKD-spectrum disorders.
Sagittal CT image of bilateral renal cysts