These authors contributed equally to this work.
A family with fragile X syndrome, Duchenne muscular dystrophy and ichthyosis transmitted by an asymptomatic carrier
Version of Record online: 10 APR 2013
© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Volume 85, Issue 3, pages 286–289, March 2014
How to Cite
Todorova, A., Litvinenko, I., Todorov, T., Tincheva, R., Avdjieva, D., Tincheva, S. and Mitev, V. (2014), A family with fragile X syndrome, Duchenne muscular dystrophy and ichthyosis transmitted by an asymptomatic carrier. Clinical Genetics, 85: 286–289. doi: 10.1111/cge.12148
The authors declare that they have no conflict of interest.
- Issue online: 27 JAN 2014
- Version of Record online: 10 APR 2013
- Accepted manuscript online: 22 MAR 2013 12:39PM EST
- Manuscript Revised: 15 MAR 2013
- Manuscript Accepted: 15 MAR 2013
- Manuscript Received: 25 JAN 2013
- Alexander von Humboldt Foundation
- DMD gene;
- FMR1 gene;
- genomic instability;
- STS gene
The human X chromosome carries regions prone to genomic instability: deletions in the Xp22.31 region, involving the steroid sulfatase gene (STS) cause X-linked ichthyosis; rearrangements in the Xp21.2 region are associated with Duchenne or Becker muscular dystrophies (DMD or BMD); and the Xq27.3 unstable region, containing the (CGG)n repeat expansion in the FMR1 gene is associated with fragile X syndrome. We report on a family with two affected boys, the elder diagnosed with fragile X syndrome, the younger with DMD, and both suffering from severe ichthyosis. The family was analyzed by polymerase chain reaction, multiplex ligation-dependent probe amplification and haplotype analysis. The mother proved to be an asymptomatic carrier of all three non-contiguous mutation events, involving the STS gene, the DMD gene and a FMR1 expansion. To the best of our knowledge, this is the first description of an asymptomatic carrier of three different X-linked disorders, involving severe genetic rearrangements on both long and short arms of the X chromosomes. The boy with fragile X syndrome has inherited a triple recombinant maternal X chromosome, this way inheriting the FMR1 expansion and ichthyosis, originating most probably from different maternal Xes and excluding the DMD gene deletion. The transmission of these extremely defective maternal chromosomes to the next generation involved several recombinations.