Multiple cutaneous and uterine leiomyomas: refinement of the genetic locus for multiple cutaneous and uterine leiomyomas on chromosome 1q42.3-43.

Cutaneous leiomyomas, rare benign tumors originating from the arrector pili muscle of the hair follicle, can be associated with the common uterine fibroids in a syndrome called multiple cutaneous and uterine leiomyomas. Multiple cutaneous and uterine leiomyomas are inherited as an autosomal dominant trait, providing an excellent opportunity for the study of the common non-Mendelian manifestation of isolated uterine fibroids. This study reports the clinical and molecular characterization of an extended family with multiple cutaneous and uterine leiomyomas. Linkage analysis has shown that the disease in this family is linked to the recently reported genetic locus for multiple cutaneous and uterine leiomyomas, with a maximum two-point LOD score of 4.453 for markers D1S2670, D1S2785, D1S547, and D1S1609. The identification of key recombination events has allowed us to refine substantially the location of the genetic locus for multiple cutaneous and uterine leiomyomas, from 14 cM to an interval of 4.55 or 7.19 cM, depending on the final phenotype of a young family member in which one of the key recombination events has occurred. In addition, we provide a description of the interesting pattern and progression of the skin phenotype in this four-generation kindred. The refinement of the genetic locus for multiple cutaneous and uterine leiomyomas and the availability of an extended multigeneration pedigree will facilitate the identification of the mutated gene responsible for multiple cutaneous and uterine leiomyomas, which, in turn, may provide key information for the understanding of the molecular basis of the common uterine fibroids.