Clinical Expression of NF1 in Monozygotic Twins

摘要: Twin studies can be a valuable tool in understanding variable expression NF1. Evidence is accumulating that monozygotic (MZ) twins are not truly “identical” and may have multiple phenotypic differences as well related to postzygotic epigenetic events. There been at least 45 pairs of confirmed MZ with NF1 reported the medical literature. Phenotypic extreme complete discordance for diagnosis found due somatic mutation. Multiple shown much more similar numbers cafe-au-lait spots cutaneous neurofibromas than siblings or distant relatives, suggesting germline modifying genes play significant role regulating these features. Learning disabilities, ADHD, speech disorder highly concordant twins, again implying major genes. Valuable information has also come from traits discordant co-twins. The majority neoplasms, including optic pathway gliomas malignant peripheral nerve sheath tumors (MPNSTs), fell into this category, consistent sporadic second-hit events known occur those tumors. With only few exceptions, plexiform occurred different areas body when Most dystrophic skeletal complications, such scoliosis tibial pseudarthrosis, were nonhereditary Other possible causes suggested by twin include differences, promoter methylation mutations other