PTBP1 and microcephaly: This mechanism involves Polypyrimidine tract-binding protein (PTBP1), which is also known to function in alternative splicing for Filamin A (FLNA) (Zhang et al., 2016), a causative gene for microcephaly in mice, and the deregulation of this alterative splicing leads to periventricular heterotopia (PH) in human (Lian et al., 2012).