However, most WHS patients harbor mutations that extend beyond these critical regions, affecting several flanking genes such as TACC3, FGFR3, SLBP, CTBP1, CPLX1, PIGG, MSX1, and FGFRL1, demonstrating that deletions encompassing these genes may also contribute to the presentation of WHS symptoms (Hannes et al., 2010; Endele et al., 2011; Battaglia et al., 2015; Ho et al., 2016; Rutherford and Lowery, 2016). Here, PIGG is linked to Wolf-Hirschhorn syndrome.