A 3335-g female infant was born to an unrelated parent. She was referred to our hospital after delivery due to multiple cardiac homogeneous echogenicity in the antenatal period. Her Family history was unremarkable, and both parents and her older sister had no rhabdomyosarcoma or other abnormalities. At 3 months of age, his height was 63 cm (1.26 SDS), and his weight was 6.6 kg (1.08 SDS). Physical examination revealed hypopigmented macules on trunk. Transthoracic echocardiography showed a secundum defect in the interatrial septum and echogenic homogeneous structures as 9 × 4 mm in diameter in the interventricular septum, 3 × 6 mm in the right ventricle, 3 × 6 mm in the right ventricular outflow tract, and multiple rhabdomyomas towards the ventricular outflow tract in the left ventricle. Three months later, she started to have seizures 1–3 times a day, lasting several seconds, with tonic contractions of the extremities. Electroencephalography was compatible with active multifocal epileptic disorder and hypsarrhythmia. Extensor spasm was observed during the seizure. The patient was started on vigabatrin treatment, and brain magnetic resonance imaging revealed a thin corpus callosum, cortical and subcortical tubercles, and multiple subependymal nodules (Fig. 1). The patient was evaluated by pediatric cardiology and neurology departments, and genetic analysis was studied with a preliminary diagnosis of TSC. A pathogenic heterozygous deletion between 31 and 42 exons in TSC2 gene was detected in targeted next-generation sequencing for TSC1 and TSC2 genes. The patient was diagnosed as TSC type 2.

Images of cranial MRI of the patient. The corpus collosum is thin. The lateral ventricles are wide, especially in their posterior part. Contour lobulation is observed in the superior wall of the right lateral ventricle. Numerous subependymal millimeter-sized nodular lesions were noted on the lateral ventricular walls. There is an appearance of tubercles affecting the cortex-subcortical areas, which are widespread in both cerebral hemispheres, especially in the frontal and parietal lobes

Abdominal ultrasound performed for additional anomalies revealed a multiloculated cyst reaching 1 cm in size in the liver. The right kidney was 58 × 23 mm, and the left kidney was 53 × 23 mm in size. Bilateral renal parenchymal echogenicity increased, and corticomedullary differentiation disappeared. Multiple cortical cysts smaller than 6 mm were observed in both kidneys, in accordance with autosomal dominant polycystic kidney disease (ADPKD) (Fig. 2). The patient was referred to the Department of Pediatric Nephrology. Targeted next-generation sequencing analysis for cystic kidney diseases revealed a heterozygous deletion in exons 28–46 of the PKD1 gene. Therefore, the patient was diagnosed as PKD1/TSC2 contiguous gene deletion syndrome.

Image of urinary ultrasound of the patient. Increased parenchymal echogenicity and multiple parenchymal cystic lesions in the right kidney

During follow-up, clinical seizure did not recur under vigabatrin, and she was compatible with her age neurodevelopmentally. At 14 months of age, she was found to be hypertensive (114/68 mmHg, > 99th) during routine outpatient clinic examination. Her height was 76 cm (− 0.82 SDS) and weighed 10 kg (− 0.08 SDS). Kidney function tests were normal, and there was no hematuria or proteinuria. On ultrasound, both were larger than normal in size (right kidney 125 × 63 mm, left 131 × 70 mm). There were multiple parenchymal cystic lesions in both kidneys, the largest on the left (approximately 45 × 40 mm in size). In addition, a hyperechoic nodular lesion 10 × 7 mm in size, angiomyolipoma, was observed in the lower pole of the right kidney. Since angiotensin-converting enzyme inhibitors are used as the drug of choice to control blood pressure in cystic kidney disease [3], the patient was planned to start enalapril; however, normotension was maintained with amlodipine and propranolol until bilateral renal artery stenosis was excluded. Subsequent renal Doppler imaging did not reveal any appearance compatible with stenosis, and therefore, a gradual replace of the current medications to enalapril was planned with close follow-up.