Hereditary leiomyomatosis and renal cell carcinoma is caused by mutations – or genetic changes – in the FH gene. This gene encodes for the FH protein, which normally helps break down another protein (HIF), thereby blocking the release of growth factors.
Now if the FH gene is present in an altered form, the FH protein will not be produced correctly. This will prevent the HIF protein being broken down correctly, leading to an accumulation of the HIF protein. The resulting increased release of growth factors can lead to the development of benign and malignant tumors.
HLRCC can be passed on by parents to their children. In these cases, it is inherited as an autosomal dominant disease. It is also possible for the genetic change in the FH gene to occur as a spontaneous or new mutation, called a de novo mutation.