Recent studies also suggest that the interaction of alcohol with specific genes involved in brain development and the development of facial features may affect the FASD phenotype. A study in zebrafish, for example, examined the interaction of alcohol with the gene for platelet-derived growth factor receptor alpha (Pdgfra) (McCarthy et al. 2013). This gene is involved in cellular migration and proliferation and is necessary for proper migration of neural crest cells, which contribute to the formation of diverse structures, including the face. The researchers found that pdgfra interacts with alcohol to protect against severe craniofacial defects. Specifically, more than 60 percent of zebrafish heterozygous for the pdgfra gene showed cranial facial defects after alcohol exposure compared with only about 10 percent of the alcohol-treated wild-type embryos (figure 4C). A genome-wide genetic scan, using single nucleotide polymorphisms (SNPs), in humans with FASD supports these findings, showing that craniofacial phenotypes seen in FASD are linked to the PDGFRA gene (McCarthy et al. 2013). A more recent study in zebrafish found that a gene involved in the development of the embryonic axis, vangl2,
