<prompt> A 12- year -old boy is referred for evaluation of nocturnal enuresis and sho stature. The blood pressure is normal. The blood urea is 112 mgdl, creatinine 6 mgd1, sodium 119 mEq1, potassium 4 mEq1, calcium 7mgd1, phosphate 6mgdl and alkaline phosphatase 400 Ul.Urinalysis shows trace proteinuria with hyaline casts; no red and white cells are seen. Ultrasound shows bilateral small kidneys and the micturating cystourethrogram is normal. The most likely diagnosis is:Alpos syndromeMedullary sponge kidneyChronic glomerulonephritisNephronophthisis  <response>: Answer is C Unilateral renal dysplasia: The multicystic dysplastic kidney is the commonest form of congenital cystic renal dysplasia, and is due to complete uretric obstruction in fetal life. The condition is usually unilateral; bilateral disease is lethal. Cystic diseases of kidney in infants Dysplastic kidney multicystic Polycystic kidney Autosomal Recessive; Autosomal dominant Multilocular cystic nephroma Renal dvsplasia. Multicvstic kidney: It is the commonest cause of renal mass in infants 