Is Cystinuria hereditary?

Cystinuria is a hereditary condition that affects the kidneys and leads to the formation of cystine stones in the urinary tract. It is caused by a genetic mutation that affects the transport of certain amino acids, specifically cystine, ornithine, lysine, and arginine.

Individuals with cystinuria inherit a faulty gene from one or both of their parents, which disrupts the normal reabsorption of cystine in the kidneys. As a result, cystine builds up in the urine and can form crystals or stones, which can be painful and may cause complications if not treated.

The inheritance pattern of cystinuria is autosomal recessive, meaning that both copies of the gene (one from each parent) must be mutated for the condition to be present. If an individual inherits only one mutated gene, they are considered carriers and typically do not experience symptoms.

When two carriers of the cystinuria gene have children, there is a 25% chance with each pregnancy that the child will inherit two mutated genes and develop cystinuria. There is a 50% chance that the child will inherit one mutated gene and become a carrier, and a 25% chance that the child will inherit two normal genes and not be affected by the condition.

Genetic testing can be done to identify individuals who carry the cystinuria gene or are affected by the condition. This can be particularly useful for family planning and early intervention to prevent complications associated with cystine stone formation.