Abstract Renal dysplasia is characterized by hypoplas- tic kidneys that contain elements of primitive tubules. Patients may develop end-stage renal failure early in life. Nephrotic syndrome is one of the most common renal diseases in childhood and may occur in association with renal dysplasia. We report a case of a child with bilateral dysplastic kidneys and steroid responsive nephrotic syn- drome (SRNS). An association between renal dysplasia with chronic renal failure and SRNS has not previously been reported in the English literature. Keywords Renal dysplasia-hypoplasia · Chronic renal failure · Nephrotic syndrome · Steroid responsive nephrotic syndrome · Focal segmental glomerulosclerosis Introduction Renal dysplasia is due to abnormal metanephric devel- opment and is characterized by hypoplastic kidneys, which contain elements of primitive tubules, mesen- chyme, immature glomeruli, and often cartilage. Corti- cal cysts may be present in some cases. Renal dysplasia occurs unilaterally or bilaterally and may be associated with obstruction or development anomalies of the uri- nary tract. Patients with renal dysplasia usually develop end-stage renal failure in the first few decades of life [1]. Nephrotic syndrome (NS), one of the common renal diseases in childhood, is characterized by edema, neph- rotic range proteinuria (≥40 mg/m 2 /h), hypoalbumine- mia, and hypercholesterolemia. Minimal change neph- rotic syndrome (MCNS) is the most frequent cause of primary childhood NS, accounting for 80–85% of all cases [2]. Children with NS, primary or secondary, have focal segmental glomerulosclerosis (FSGS) in approxi- mately 10% of cases. Secondary FSGS is a characteristic histological finding in the clinical disorders associated with hyperfiltration. A significant reduction of function- ing renal mass such as unilateral renal agenesis, renal dysplasia, oligomeganephronia, and reflux nephropathy, with maladaptive structural and functional responses in the remaining nephrons, are believed to be a principal mechanism leading to hyperfiltration [3–5]. Most chil- dren with primary NS achieve remission when treated with oral prednisone; however, even the most responsive cases of NS are likely to relapse. Cytotoxic agents are reserved for patients who respond poorly to corticoste- roid therapy. Although renal histology is the definitive diagnostic test, most children are not biopsied because the diagnosis is based on clinical and laboratory find- ings, and response to therapy [6]. We report a child with bilateral dysplastic kidneys and steroid responsive nephrotic syndrome (SRNS). An association between renal dysplasia and SRNS has not previously been reported in the English literature. Case report A male infant born prematurely at 29 weeks by normal delivery weighed 1953 g. Oligohydramnios was diagnosed by prenatal ul- trasound at the 18th week of pregnancy. At 29 weeks of gestation the mother arrived at the delivery room in labor with no preceding events. An ultrasound performed after birth showed bilateral dys- plastic kidneys, with no reflux on cystourethrography. A radio- nuclide scan with diethylenetriaminepentaacetic acid (DTPA) did not show obstruction. Until the age of 5 years his renal function was stable with blood urea nitrogen (BUN) 60–75 mg/dl, serum creatinine levels 2.2–2.5 mg/dl and normal urinalysis. The child was treated with calcium carbonate, calcitriol, sodium bicarbonate and erythropoie- tin. At 5 years of age the patient was admitted with periorbital ede- ma and proteinuria. Blood pressure was 95/70 mmHg. Laboratory evaluation revealed: hemoglobin 90 g/l, white blood cell count 8.9×10 9 /l, platelets 236×10 9 /l, BUN 150 mg/dl, serum creatinine V. Smolkin ( ✉ ) · R. Halevy · A. Koren Pediatric Nephrology Unit and Pediatric Department B, Ha’Emek Medical Center, Afula, 18101, Israel e-mail: vlsmolkin@yahoo.com Tel.: +972-4-6524152, Fax: +972-4-6525589 A. Koren The Baruch Rappaport School of Medicine, Technion, Israel Institute of Technology, Haifa, Israel Pediatr Nephrol (2001) 16:515–516 © IPNA 2001 BRIEF REPORT Vladislav Smolkin · Raphael Halevy · Ariel Koren Steroid responsive nephrotic syndrome associated with bilateral renal dysplasia Received: 15 February 2000 / Revised: 29 January 2001 / Accepted: 29 January 2001