The molecular basis of the folate-sensitive fragile site FRA11A at 11q13

Cytogenet Genome Res. 2007;119(1-2):9-14. doi: 10.1159/000109612. Epub 2007 Dec 14.

Abstract

We report on the molecular basis of the rare, folate-sensitive fragile site FRA11A in chromosome band 11q13 in a family with cytogenetic expression. Five individuals express the fragile site and one was mentally retarded. Expansion of a polymorphic CGG-repeat located at the 5' end of the C11orf80 gene causes FRA11A. The CGG-repeat elongation coincides with hypermethylation of the adjacent CpG island and subsequent transcriptional silencing of the C11orf80 gene. This gene has no homology with known genes. A relationship between cytogenetic expression of the fragile site and the mental handicap seems unlikely, as FRA11A was found in a mentally retarded patient as well as in phenotypically normal carriers from the same family. However, incomplete penetrance cannot be entirely excluded.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Fragile Sites / drug effects*
  • Chromosome Fragile Sites / genetics*
  • Chromosomes, Human, Pair 11 / genetics*
  • Computational Biology
  • Female
  • Folic Acid / pharmacology*
  • Gene Expression Regulation / genetics
  • Humans
  • In Situ Hybridization, Fluorescence
  • Male
  • Pedigree
  • Phenotype

Substances

  • Folic Acid