Disruption of the X-linked gene encoding NF-kappa B essential modulator (NEMO) 
produces male embryonic lethality, completely blocks NF-kappa B activation by 
proinflammatory cytokines, and interferes with the generation and/or persistence 
of lymphocytes. Heterozygous female mice develop patchy skin lesions with 
massive granulocyte infiltration and hyperproliferation and increased apoptosis 
of keratinocytes. Diseased animals present severe growth retardation and early 
mortality. Surviving mice recover almost completely, presumably through clearing 
the skin of NEMO-deficient keratinocytes. Male lethality and strikingly similar 
skin lesions in heterozygous females are hallmarks of the human genetic disorder 
incontinentia pigmenti (IP). Together with the recent discovery that mutations 
in the human NEMO gene cause IP, our results indicate that we have created a 
mouse model for that disease.