Renal System MCAT Practice Question
A 35-year-old patient with a history of recurrent kidney stones undergoes genetic testing and is found to have a mutation in the SLC7A9 gene, which encodes a basolateral amino acid transporter in the proximal tubule. Laboratory analysis reveals elevated urinary cystine, lysine, arginine, and ornithine. This genetic condition impairs reabsorption of which class of amino acids, and what is the likely diagnosis?
Answer choices
- ANeutral amino acids; cystinosis
- BBasic amino acids; cystinuriaCorrect answer
- CAcidic amino acids; Hartnup disease
- DBranched-chain amino acids; maple syrup urine disease
- ESulfur-containing amino acids; homocysteinuria
- FImino acids; familial hyperprolinemia
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