How to cite this article: Yeung A, Francis D, Giouzeppos O, Amor DJ. 2009. Pallister–Killian syndrome caused by mosaicism for a supernumerary ring chromosome 12p. Am J Med Genet Part A 149A:505–509.
Pallister–Killian syndrome caused by mosaicism for a supernumerary ring chromosome 12p†
Version of Record online: 12 FEB 2009
Copyright © 2009 Wiley-Liss, Inc.
American Journal of Medical Genetics Part A
Volume 149A, Issue 3, pages 505–509, March 2009
How to Cite
Yeung, A., Francis, D., Giouzeppos, O. and Amor, D. J. (2009), Pallister–Killian syndrome caused by mosaicism for a supernumerary ring chromosome 12p. Am. J. Med. Genet., 149A: 505–509. doi: 10.1002/ajmg.a.32664
- Issue online: 24 FEB 2009
- Version of Record online: 12 FEB 2009
- Manuscript Accepted: 20 OCT 2008
- Manuscript Received: 10 JUL 2008
- Pallister–Killian syndrome;
- chromosome 12;
- tetrasomy 12p;
- ring chromosome
Pallister–Killian syndrome (PKS) is a rare but distinctive chromosomal syndrome distinguished by severe intellectual impairment, characteristic facial features, and variable structural anomalies. The characteristic cytogenetic abnormality in PKS is a supernumerary isochromosome 12p that confers mosaic tetrasomy. We describe a female child with PKS in whom tetrasomy 12p resulted from a supernumerary ring chromosome containing two copies of chromosome 12cen p13, a novel cytogenetic finding. The ring chromosome exhibited tissue-limited mosaicism, being absent in blood but detected in 38% of buccal mucosa cells and 41% of skin fibroblasts. Our patient demonstrated the typical dysmorphic characteristics of PKS, but her development was relatively advanced in comparison to children with isochromosome PKS. Her milder developmental phenotype may be attributable to differences in the mosaic distribution or the genomic content of the ring chromosome compared to mosaic isochromosome 12p. © 2009 Wiley-Liss, Inc.