This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': "A–13–year old boy is referred for evaluation of nocturnal enuresis and short stature. His blood pressure is normal. The hemoglobin level is 8g/dl.urea 112 mg/dl, creatinine 6 mg/dl, sodium 119 mEq/ dl, potassium 4 mEq/l, calcium 7 mg/dl, phosphate 6 mg/dl and alkaline phosphatase 300 U/I. 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 – \nSelect and explain. \nA. Alport's syndrome, B. Medullary sponge kidney., C. Chronic glomerulonephritis., D. Nephronophthisis", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Features seen in this 13 yr. old boy\nShort Stature\nNocturnal enuresis\nNormal B.P.\nReduced hemoglobin\nHyponatremia (N level in 136-145 meq/dl)\nHypocalcemia (N level is 9-10.5 mg/dl)\nNormal potassium level (N is 3.5 to 5 meq/dl)\nB/L small kidneys\nIncreased blood urea (N is 10 - 40 mg/dl)\nIncreased alkaline phosphates (N is upto 130 IU)\nIncreased serum creatinine (N is < 1.5 m g/dl)\nThis pt. gives a classical presentation of nephronophthisis,\xa0\n\nAbout other options\nAlport syndrome\n\nIt can be easily ruled out as it presents with\nMicroscopic hematuria (first symptom) \xa0\xa0\xa0 \xa0 \xa0 \xa0 \xa0 \xa0\xa0\nProteinuria\xa0\xa0\xa0\xa0\xa0\nSensorineural hearing loss\xa0\xa0\xa0\xa0\xa0\xa0\nb/l\xa0anterior lenticonus\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\n\nMedullary sponge kidney\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\n\nEasily ruled out as the kidneys are normal or increased is size in MSK and also the age of presentation is third or fourth decade.\n\nChronic glomerulonephritis\n\npts of CGN usually have heavy proteinuria, frank or occult hematuria and hypertension.', 'role': 'assistant'}]