Mutations disrupting selenocysteine formation cause progressive cerebello-cerebral atrophy

  • Am J Hum Genet. 2010 Oct 8;87(4):538-44. doi: 10.1016/j.ajhg.2010.09.007.
Orly Agamy  1 ,  Bruria Ben Zeev ,  Dorit Lev ,  Barak Marcus ,  Dina Fine ,  Dan Su ,  Ginat Narkis ,  Rivka Ofir ,  Chen Hoffmann ,  Esther Leshinsky-Silver ,  Hagit Flusser ,  Sara Sivan ,  Dieter Söll ,  Tally Lerman-Sagie ,  Ohad S Birk
Affiliations
  • 1. Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev, Ben Gurion University, Beer-Sheva, Israel.
PMID: 20920667 DOI: 10.1016/j.ajhg.2010.09.007
Abstract

The essential micronutrient selenium is found in proteins as selenocysteine (Sec), the only genetically encoded amino acid whose biosynthesis occurs on its cognate tRNA in humans. In the final step of selenocysteine formation, the essential enzyme SepSecS catalyzes the conversion of Sep-tRNA to Sec-tRNA. We demonstrate that SepSecS mutations cause autosomal-recessive progressive cerebellocerebral atrophy (PCCA) in Jews of Iraqi and Moroccan ancestry. Both founder mutations, common in these two populations, disrupt the sole route to the biosynthesis of the 21st amino acid, Sec, and thus to the generation of selenoproteins in humans.