A 17-year-old male presents with acute left flank pain and gross hematuria. Vital signs show BP 128/82 mmHg, HR 92 bpm, RR 16, temp 37.2°C, SpO2 98%. Urinalysis reveals hexagonal crystals and 3+ blood. Serum creatinine is 0.9 mg/dL. He denies fever and reports recurrent kidney stones since age 8 with no prior UTIs. Urine pH is 5.2. Which metabolic pathway defect most likely explains his presentation?
- A)Cystathionine beta synthase deficiency
- B)Deficiency of homogentisate oxidase
- C)Defect in uric acid transporter URAT1
- D)Renal proximal tubular transporter defect for cystine, ornithine, lysine, and arginineGABARITO
- E)Deficiency of xanthine oxidase
Explicação
This patient has cystinuria due to an inherited defect in the renal proximal tubular and intestinal transporter for cystine, ornithine, lysine, and arginine. Cystine is poorly soluble and precipitates as hexagonal stones, especially in acidic urine. Hydration ... Ver explicação completa e trilha adaptativa →