Clinical and Genetic Characterization of a Patient With SEC63-Related Autosomal Dominant Polycystic Liver Disease and an IFT140 Pathogenic Variant Associated With Polycystic Kidney Disease

A 40-year-old female with a family history of polycystic kidney disease presented for evaluation. She was originally diagnosed with liver cysts in 2015 following an emergency department visit for suspected cyst rupture. Laboratory studies demonstrated preserved renal and hepatic function, with a creatinine level of 0.65 mg/dL and an estimated glomerular filtration rate (eGFR) of 114 mL/min/1.73 m². Abdominal MRI revealed numerous hepatic cysts, the largest measuring 12.9 × 10.8 cm, along with multiple bilateral renal cysts. The largest renal cyst measured 5.2 cm and was haemorrhagic and exophytic. Genetic testing identified heterozygous pathogenic variants in both SEC63 and IFT140. The patient is currently managed with serial imaging surveillance for hepatic cyst burden, portal hypertension, and total kidney volume. This case illustrates a rare double-hit genetic entity. While SEC63 mutations rarely involve the kidneys, the co-existence of an IFT140 variant likely contributed to the development of bilateral renal cysts. This report emphasizes the role of comprehensive genetic testing in atypical polycystic presentations and highlights the importance of multidisciplinary monitoring in complex ciliopathies. Informed consent was obtained for publication of this case report.