Autosomal recessive mutations in nuclear transport factor KPNA7 are associated with infantile spasms and cerebellar malformation

Alex R. Paciorkowski, Judy Weisenberg, Joshua B. Kelley, Adam Spencer, Emily Tuttle, Dalia Ghoneim, Liu Lin Thio, Susan L. Christian, William B. Dobyns, Bryce M. Paschal

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

Nuclear import receptors of the KPNA family recognize the nuclear localization signal in proteins and together with importin-β mediate translocation into the nucleus. Accordingly, KPNA family members have a highly conserved architecture with domains that contact the nuclear localization signal and bind to importin-β. Here, we describe autosomal recessive mutations in KPNA7 found by whole exome sequencing in a sibling pair with severe developmental disability, infantile spasms, subsequent intractable epilepsy consistent with Lennox-Gastaut syndrome, partial agenesis of the corpus callosum, and cerebellar vermis hypoplasia. The mutations mapped to exon 7 in KPNA7 result in two amino-acid substitutions, Pro339Ala and Glu344Gln. On the basis of the crystal structure of the paralog KPNA2 bound to a bipartite nuclear localization signal from the retinoblastoma protein, the amino-acid substitutions in the affected subjects were predicted to occur within the seventh armadillo repeat that forms one of the two nuclear localization signal-binding sites in KPNA family members. Glu344 is conserved in all seven KPNA proteins, and we found that the Glu354Gln mutation in KPNA2 is sufficient to reduce binding to the retinoblastoma nuclear localization signal to approximately one-half that of wild-type protein. Our data show that compound heterozygous mutations in KPNA7 are associated with a human neurodevelopmental disease, and provide the first example of a human disease associated with mutation of a nuclear transport receptor.

Original languageEnglish
Pages (from-to)589-593
Number of pages5
JournalEuropean Journal of Human Genetics
Volume22
Issue number5
DOIs
StatePublished - May 2014

Keywords

  • KPNA7
  • Lennox Gastaut syndrome
  • cerebellar vermis hypoplasia
  • importins
  • infantile spasms
  • whole exome sequencing

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    Paciorkowski, A. R., Weisenberg, J., Kelley, J. B., Spencer, A., Tuttle, E., Ghoneim, D., Thio, L. L., Christian, S. L., Dobyns, W. B., & Paschal, B. M. (2014). Autosomal recessive mutations in nuclear transport factor KPNA7 are associated with infantile spasms and cerebellar malformation. European Journal of Human Genetics, 22(5), 589-593. https://doi.org/10.1038/ejhg.2013.196