When the FH gene is mutated, its causes a disorder called Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC). Symptoms of this disorder include the growth of benign tumors in the skin called cutaneous leiomyomas, uterine leiomyomas (fibroids) and an increased risk for renal (kidney) cancer. While uterine fibroids are vert common, people with HLRCC tend to develop more fibroids than the average female and may start developing them at a young age. There is a small risk for the fibroids to become cancerous. The type of renal cancer often seen with HLRCC is renal cell carcinoma. The lifetime risk for developing these renal tumors is thought be around 15%. There have been reports of Wilms tumors (a type of childhood kidney cancer) associated with HLRCC as well, although it is rare.
The FH gene is critical in making an enzyme that plays an important role in cellular respiration, a very important process that provides your cells with energy. However, when this gene is mutated, it does not produce a normally functioning enzyme. This may lead to an oxygen buildup in cells which can provoke cancer.
HLRCC is inherited in an autosomal dominant manner, meaning each first degree relative (parent, child, and sibling) of an individual with this condition has a 50% chance of inheriting the disease causing mutation.