Clinical feature: 

Definition: This disease is characterized by multiple cutaneous and uterine leiomyomata. The inheritance is autosomal dominant with incomplete penetrance.

Pathogenesis: The disease is caused by mutations of the FH gene (fumarate hydratase). Relevant mutations can be found in 85% of patients. Amon them 58% missens, 27% frameshift, 9% nonsense, and 7% mutation affecting large parts of the gene.

Epidemiology: It is a rare disease, so it is generally accepted that uterus leiomyomatomas and kidney tumors are not sufficient to make the clinical diagnosis, if skin leiomyomas are not present.
In contrary, in 6% of patients with a mutation, a kidney tumor can be found in family members by radiological methods.

Clinical picture: The most obvious clinical symptome are cutaneous leiomyomas. Uterine leiomyomata and even sarkomata may occur in women. Malignant tumors associated with this disease may be found in prostata and breats.

Diagnostics: 

Diagnosis: The leading symptome are multiple cutaneous leiomyomas. Only if such a dermatologically confirmed presentation is associated with tumors a molecular genetic test is indicated.
Heterozygous patient should be screened for kidney tumors by radiological methods. A thorough clinician keeps an eye on other possible tumors, too.

Strategy: In any patient with malignant tumors and skin leiomyomas a molecular genetic test is recommended. If a mutation is found, a family screening will follow, and finally, all affected family members shall perpetually a scrutinely examined for tumors.

Literature: 

Alam NA et al. (2005) Fumarate hydratase mutations and predisposition to cutaneous leiomyomas, uterine leiomyomas and renal cancer.