ABCC6 and incontinentia pigmenti: To shed light on the genetic mechanisms of IP in PXE, in the following, we tested whether the observed IP of c.1171A>G (p.Arg391Gly) could be explained by an effect on splicing, which frequently causes reduced penetrance (Cogan et al., 2012; Rave‐Harel et al., 1997), or by its obligate association with another pathogenic variant(s) within the ABCC6 gene either in trans or cis position.