Analysis of mitochondrial DNA in discordant monozygotic twins with neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is the most frequent neurocutaneous disorder with autosomal dominant inheritance. Phenotype variability is high ranging from merely several café-au-lait spots to malignant peripheral nerve sheath tumors or severe disfigurement through plexiform neurofibromas. Identification of genetic factors that modify the NF1 phenotype would contribute to the understanding of NF1 pathophysiology and improve patient counselling.

Expression of prothrombin, thrombin and its receptors in human scars.

The coagulation system is thought to play a pivotal role during the initial phase of wound healing, but mechanisms and cells involved are only partly understood. We have therefore examined human scars for the expression of thrombin, its precursor prothrombin and the thrombin receptors, thrombomodulin (TM) and protease-activated receptor-1 (PAR-1), compared with normal skin. Biopsies of scars were obtained from primary excision sites of melanoma patients (n = 20) and were compared with normal skin distant from the scar (n = 10), using immunohistochemistry.

Subclassification of nerve sheath tumors by gene expression profiling.

Nerve sheath tumors are the most common tumors of Neurofibromatosis type 1 (NF1) patients. Dermal neurofibromas develop in nearly all NF1-patients, whereas plexiform neurofibromas are only observed in one-third of the patients. NF1-patients have about a 10% lifetime risk for developing malignant pheripheral nerve sheath tumors (MPNST).