The mechanisms by which PAH-related reduction of BDNF may cause child developmental problems have not been determined but recent studies have pointed to several potential mechanistic pathways: alteration in the conversion of proBDNF to mBDNF which influences levels of signaling proteins involved in LTP; disruption of activation of TrkB; and induction of methylation changes in BDNF. This evidence concerns the gene NTRK2 and pulmonary arterial hypertension.