GJB4 and 22q11.2 deletion syndrome: The four positional candidate genes associated with cell adhesion (armadillo repeat gene deleted in velocardiofacial syndrome (ARVCF), gap junction protein beta 4 (GJB4), gap junction protein beta 5 (GJB5), and junction mediating and regulatory protein, p53 cofactor (JMY)) are of interest as the function of cell-cell junctions must change during early pregnancy establishment [22].