A 14-year-old boy presents with recurrent renal colic and hematuria. Vital signs show BP 118/76 mmHg, HR 88/min, RR 16/min, temperature 37.2°C. Urine microscopy reveals hexagonal crystals; serum creatinine is 0.9 mg/dL. He denies fever or dysuria. Family history is significant for a sibling with identical presentations requiring similar management. Which amino acid shares the same proximal tubular transport defect as the substance forming these stones?
- A)LysineGABARITO
- B)Tyrosine
- C)Alanine
- D)Valine
- E)Glutamine
Explicação
Lysine is correct. Cystinuria is caused by defective proximal tubular reabsorption of cystine and the dibasic amino acids ornithine, lysine, and arginine. Poorly soluble cystine precipitates in urine and forms recurrent stones with characteristic hexagonal cry... Ver explicação completa e trilha adaptativa →