microscopic examination demonstrates that the cerebral cortex is in fact abnormally thin and has abnormal lamination; typically the cortex is unlayered or has four layers, in contrast to the normal six layers. the most superficial layers between adjacent small gyri appear fused, with the pia (layer of the meninges) bridging across multiple gyri. prenatal diagnosis for bfpp is also available for pregnancies at risk if the gpr56 mutations have been identified in an affected family member.