Mechanism of renal cyst formation in a child with tuberous sclerosis complex: a case report

Abstract Background Tuberous sclerosis complex (TSC) is a multisystem genetic disorder characterized by the development of benign tumors in various organs, including the brain, kidneys, heart, lungs, skin, and eyes. Herein, an infant who was followed up with a diagnosis of TSC and multiple cysts which were found in the kidneys was presented, and the mechanism of renal cyst formation in TSC was elucidated. Case presentation An infant was referred to our hospital after delivery due to multiple cardiac homogeneous echogenicity in the antenatal period. Transthoracic echocardiography showed multiple rhabdomyomas in both ventricles. Three months later, she started to have seizures 1–3 times a day. Electroencephalography was compatible with active multifocal epileptic disorder and hypsarrhythmia. Brain magnetic resonance imaging revealed a thin corpus callosum, cortical and subcortical tubercles, and multiple subependymal nodules. Abdominal ultrasound revealed a multiloculated cyst reaching 1 cm in size in the liver, and multiple cortical cysts smaller than 6 mm were observed in both kidneys, in accordance with autosomal dominant polycystic kidney disease (ADPKD). Pathogenic deletions between 31–42 exons in TSC2 gene and 28–46 exons in PKD1 gene were detected, and the patient was diagnosed as PKD1/TSC2 contiguous gene deletion syndrome. Conclusion The coexistence of TSC and ADPKD is a rare occurrence but has been documented. Regular follow-up visits with healthcare providers, including nephrologists, cardiologist, neurologists, dermatologists, and other specialists as needed, are essential for the comprehensive management of coexistence of TSC and ADPKD. Individualized treatment plans should be developed based on the specific needs and manifestations of each patient, with a focus on optimizing outcomes and improving quality of life.