Cystinuria

Cystinuria is a hereditary disorder in which the kidneys do not properly reabsorb the amino acid cystine, which promotes its buildup in the urine and the formation of stones in the urinary tract.

Why it happens: It is due to a genetic alteration in the transport of certain amino acids in the renal tubules. As cystine becomes concentrated, it tends to crystallize and form stones that can recur throughout life.

Common manifestations: It usually presents with intense pain in the flank or back, blood in the urine, and repeated episodes of stones, sometimes from an early age.

Who to consult: Follow-up is handled by the urologist and, in children, by the pediatric nephrologist or the pediatrician, with support from the nephrologist when more detailed metabolic management is needed. If you have recurrent kidney pain or frequent stones, it is advisable to have a professional study your case individually.