, also called multiple cutaneous and uterine leiomyomatosis (MCUL or MCUL1), is a genetic condition in which people develop benign (non-cancerous) tumors containing smooth muscle tissue (leiomyomas) in the skin and, if female, also in the uterus. In some families aggressive kidney cancer also occurs as part of the complex and is termed as hereditary leiomyomatosis and renal cell cancer (HLRRC). The complex is often referred to as MCUL/HLRRC (multiple cutaneous and uterine leiomyomatosis/hereditary leiomyomatosis and renal cell cancer) in the medical literature. The cause of both MCUL and HLRCC is a gene called fumarate hydratase (FH), an enzyme involved in the making of energy for the body. MCUL is inherited in an autosomal dominant pattern, which means that a person needs to inherit only one mutated copy of the FH gene to have symptoms of the condition. The symptoms vary from person to person, even within a family. Treatment is based on the person's specific symptoms. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.