Diagnostic Problems Associated with Cystinuria

Abstract

To elucidate the role of the urinary cystine concentration for the formation of urinary stones, 190 stone-formers were evaluated in this prospective study. Seven patients (3.8%) were heterozygous and one patient (0.5%) was homozygous for cystinuria; only two (1%) of them were cystine stone-formers. Two patients with calcium stones were heterozygous for cystinuria. This study confirms the observation that elevated concentrations of urine cystine are relatively infrequent among patients with urinary stones.

Keywords:

• urolithiasis
• cystinuria