Incontinentia pigmenti (IP) (Bloch-Sulzberger-syndrome, OMIM #308300) is a rare hereditary multisystemic neuroectodermal disorder caused by pathogenic variants in the IKBKG gene (formerly known as NEMO (nuclear factor-kappa B (NF-kB) essential modulator)) on X chromosome. This evidence concerns the gene NFKB1 and incontinentia pigmenti.