<prompt>  A 12-year-old boy is referred for evaluation of nocturnal enuresis and short stature. The blood pressure is normal. The blood urea is 112 mgdl, creatinine 6 mgdl, sodium 119 mEql, potassium 4 mEcill, calcium 7 mgdl, phosphate 6 mgdl 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 -Alports syndromeMedullary sponge kidneyChronic glomerulonephritisNephronophthisis 