The NEMO mutation creating the most-upstream premature stop codon is hypomorphic because of a reinitiation of translation

Am J Hum Genet. 2006 Apr;78(4):691-701. doi: 10.1086/501532. Epub 2006 Feb 15.


Amorphic mutations in the NF- kappa B essential modulator (NEMO) cause X-dominant incontinentia pigmenti, which is lethal in males in utero, whereas hypomorphic mutations cause X-recessive anhidrotic ectodermal dysplasia with immunodeficiency, a complex developmental disorder and life-threatening primary immunodeficiency. We characterized the NEMO mutation 110_111insC, which creates the most-upstream premature translation termination codon (at codon position 49) of any known NEMO mutation. Surprisingly, this mutation is associated with a pure immunodeficiency. We solve this paradox by showing that a Kozakian methionine codon located immediately downstream from the insertion allows the reinitiation of translation. The residual production of an NH(2)-truncated NEMO protein was sufficient for normal fetal development and for the subsequent normal development of skin appendages but was insufficient for the development of protective immune responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromosomes, Human, X
  • Codon, Terminator*
  • DNA
  • Genes, Lethal
  • Humans
  • I-kappa B Kinase / genetics*
  • Incontinentia Pigmenti / genetics
  • Molecular Sequence Data
  • Mutation*
  • Protein Biosynthesis*


  • Codon, Terminator
  • IKBKG protein, human
  • DNA
  • I-kappa B Kinase