Incontinentia pigmenti (IP) is an X-linked genodermatosis affecting the skin and other sites, including the teeth, nails, hair, eyes and nervous system defects in female patients. Generally lethal in males, there are only a few known cases of males surviving this condition. Nuclear factor (NF)-κB essential modulator (NEMO), also known as inhibitor of kappa light polypeptide gene enhancer in B cells, kinase gamma (IKBKG), constitutes an essential activator of NF-κB. Over 80% of female patients with IP carry a common deletion mutation involving exons 4-10 of the IKBKG/NEMO gene. We present the case of a male infant (XY) with IP with no concomitant complications. Polymerase chain reaction (PCR) assay showed that the exon 4-10 deletion band was significantly stronger in the skin sample than in blood. Subsequently, long-range PCR was performed periodically to confirm the spontaneous regression of mutant cells from his blood. Over a period of 6 years, the 2.6-kb mutant band gradually became weaker, but we did not confirm complete regression. Our patient was a healthy, 8-year-old male child with no complications despite the presence of a 2.6-kb mutant band in his blood. Further follow up is necessary to assess for complications that may develop later.
Keywords: inhibitor of kappa light polypeptide gene enhancer in B cells, kinase gamma; nuclear factor kappaB essential modulator; incontinentia pigmenti; male; somatic mosaicism.
© 2017 Japanese Dermatological Association.