GANAB-Associated Severe Autosomal Dominant Polycystic Kidney Disease in an 18-Year-Old Female: A Case Report.

Autosomal dominant polycystic kidney disease (ADPKD) is a hereditary disorder, characterized by the formation of multiple cysts in the kidneys, leading to progressive kidney enlargement and, eventually, renal failure. It is most frequently associated with PKD1 or PKD2 mutations, although rare variants, such as the GANAB gene, are also associated, but they present as a milder renal phenotype. ADPKD patients often present with renal manifestations, such as hypertension, abdominal pain, hematuria, or urinary tract infections, along with extrarenal manifestations, such as liver cysts, heart valve disease, and cerebral aneurysms. ADPKD is usually diagnosed in the fourth or fifth decade of life.  This case report discusses the clinical presentation, diagnostic approach, and management of an 18-year-old female patient with no known first-degree family history of ADPKD, who presented with hypertension and bilateral renal cysts on ultrasound. The diagnosis was confirmed by imaging studies and genetic testing. The GANAB gene mutation found in this patient is typically associated with mild kidney disease; however, according to the Mayo Clinic Imaging Classification (MIC) for ADPKD, our patient falls under Classification 1E, which is predictive of rapid progression to end-stage renal disease (ESRD). It highlights the challenges in treating young patients with ADPKD, given the limited studies available for managing this progressive disease in the young population. This case questions the assumption that GANAB-associated ADPKD progresses in a mild manner. Clinicians should prioritize vigilant monitoring and a multidisciplinary approach for young patients with high-risk imaging characteristics, regardless of their genetic findings.