microRNAs and Molecular Pathogenesis of Microcephaly.

Microcephaly is a clinical condition defined as a reduction in head circumference and brain volume. The abnormal brain size may result from pathological neural stem cell (NSC) proliferation, survival, differentiation and migration during the development of the cerebral cortex. This process is controlled by many factors, including microRNAs that normally silence target genes at the posttranscriptional level. In this review, we will discuss the roles of microRNAs involved in different stages of the cortical development to shed light on the pathogenesis of microcephaly. Understanding the molecular mechanisms of microRNA-mediated cortical development may help develop a means of microRNA-based diagnosis and treatment for microcephaly in humans.