Type of disease: Rare conditions
Cystinuria is an inherited condition characterized by the buildup of cystine crystals or stones in the kidneys and bladder. Cystine is an amino acid, one of the building blocks of proteins. As the kidneys filter blood to create urine, cystine is normally absorbed back into the bloodstream. People with cystinuria cannot properly reabsorb cystine into their bloodstream and the amino acid accumulates in their urine, eventually forming crystals. As these crystals become larger, they form stones that may lodge in the kidneys or in the bladder. Sometimes cystine crystals combine with calcium molecules in the kidneys to form larger stones. These crystals and stones can create blockages in the urinary tract and reduce the ability of the kidneys to eliminate waste through urine. The stones also provide sites where bacteria may cause infections. Cystinuria is caused by mutations in the SLC3A1 and SLC7A9 genes. It is inherited in an autosomal recessive pattern. The goal of treatment is to relieve symptoms and prevent more stones.
Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.