Developmental mechanisms of sebaceous nevus syndrome caused by dysregulation of RAS/MAPK pathway

Abstract

Sebaceous nevus syndrome is a neurocutaneous disorder that shows neurological symptoms such as epilepsy, mental retardation, cerebral defect and ocular abnormality with the skin lesion called nevus sebaceous. Recently, it has been reported that sebaceous nevus syndrome is caused by somatic mutation of KRAS and HRAS during development. Interestingly, other neurodevelopmental conditions that are associated with genetic mutations in the components of RAS/MAPK pathway also show characteristic neurological symptoms including mental retardation, epilepsy, seizures, and learning disability which may explained by perturbation of RAS/MAPK pathway. We found that the mis-activation of RAS/MAPK pathway resulted in neurological defects associated with sebaceous nevus syndrome. Activation of RAS/MAPK pathway by ectopic over-expression of KRAS p.G12D in developing mouse brain caused defective neuronal migration. Using human embryonic stem cell-derived neuronal progenitor cells, we aim to characterize the gene expression profile that may explain the underlying molecular mechanisms of neurological defects caused by the mis-regulation of RAS/MAPK pathway.