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': 'An 8-year-old child suffering from recurrent attacks of polyurea since childhood presents to the paediatrics OPD. On examination the child is short statured vitals and B.P. are normal. Serum Creatinine – 6 mg%, HCO3– 16 meq, Na– 134, K+ 4.2 On USG bilateral small kidneys are seen. Diagnosis is - \nSelect and explain. \nA. Reflux Nephropathy, B. Nephronophthisis, C. Polycystic kidney disease, D. Medullary cystic kidney disease', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The lab investigations and symptoms of the child suggest Juvenile nephronophthisis.\nJuvenile nephronophthisis \n\nIt is the most common genetic cause of end-stage renal disease (renal failure) in childhood and adolescence.\nIt is an autosomal recessive disease.\nThe patients present before the age of 20 years.\nThe pt. presents with\nInability to conserve sodium because of defect of tubules leading to polyuria and polydipsia (Polyurea is resistant to vasopressin\nAnaemia\nGrowth retardation (growth retardation, malaise & pallor are secondary to anaemia which is attributed to a def. of erythropoietin production by failing kidneys)\nNo hypertension (As nephronophthisis is salt-losing nephropathy)\nProteinuria and hematuria usually are absent\nSonography shows b/1 small kidneys with multiple cysts only in the medulla (cysts may only be seen if they are large enough. They are rarely visible early in disease)\nJuvenile nephronophthisis is usually associated with many extra-renal conditions, one of which is hepatic fibrosis, which explains the high level of alkaline phosphatase in this patient.\n\nRadiographic features\n\nSmall kidneys\xa0\xa0\xa0\xa0\xa0\xa0\xa0\nLoss of corticomedullary junction &\nMultiple cysts \xa0\xa0 \xa0 \xa0\xa0\n\nAbout other options\nMedullary cystic disease\n\nPatient with medullary cystic disease presents with similar features as Juvenile Nephronophthisis but it can be differentiated by -\nThe absence of Growth Retardation\nAge of presentation is 3rd or 4th Decade.\nHypertension may occur (in JN, hypertension is not seen).\n\nIn polycystic kidney disease, there is bilateral enlargement of the kidney.\nIn reflux Nephropathy the kidneys do not decrease in size and there will be a history of frequent urinary tract infections.', 'role': 'assistant'}]