Familiares Auftreten einer segmentalen Typ-2-Manifestation der kutanen Leiomyomatose. Familial occurrence of a type 2 segmental manifestation of cutaneous leiomyomatosis

A case of linear porokeratosis superimposed on disseminated superficial actinic porokeratosis

We present a female patient with linear porokeratosis of her right arm since childhood. At the age of 67 years she additionally developed disseminated superficial actinic porokeratosis (DSAP) involving both lower legs. This uncommon coexistence of two different types of porokeratosis fulfils the clinical criteria of a type 2 segmental manifestation of an autosomal dominant skin disorder, being superimposed on the ordinary nonsegmental lesions and reflecting loss of heterozygosity that occurred at an early developmental stage. In DSAP molecular evidence of this concept is so far lacking, but such proof has already been provided in several other autosomal dominant skin disorders. Molecular analysis of cases of type 2 segmental involvement may help elucidate the genetic defect causing DSAP.

Evidence for a founder effect of the germline fumarate hydratase gene mutation R58P causing hereditary leiomyomatosis and renal cell cancer (HLRCC)

We report on the results of clinical investigation, pedigree analysis, mutation screening and haplotyping in a family with the syndrome of multiple cutaneous and uterine leiomyomas (MCUL1) and a germline missense mutation (R58P) in the fumarate hydratase gene (FH). We provide evidence for a founder effect for the identified mutation and distant relationship of our family to another familial case of MCUL1 associated with renal cell cancer, which was recently published with the same mutation.