How to Cite this Article: Kvarnung M, Lindstrand A, Malmgren H, Thåström A, Jacobson L, Dahl N, Lundin J, Blennow E. 2012. Inherited mosaicism for the supernumerary marker chromosome in cat eye syndrome: Inter- and intra-individual variation and correlation to the phenotype. Am J Med Genet Part A. 158A:1111–1117.
Inherited mosaicism for the supernumerary marker chromosome in cat eye syndrome: Inter- and intra-individual variation and correlation to the phenotype†
Article first published online: 11 APR 2012
Copyright © 2012 Wiley Periodicals, Inc.
American Journal of Medical Genetics Part A
Volume 158A, Issue 5, pages 1111–1117, May 2012
How to Cite
Kvarnung, M., Lindstrand, A., Malmgren, H., Thåström, A., Jacobson, L., Dahl, N., Lundin, J. and Blennow, E. (2012), Inherited mosaicism for the supernumerary marker chromosome in cat eye syndrome: Inter- and intra-individual variation and correlation to the phenotype. Am. J. Med. Genet., 158A: 1111–1117. doi: 10.1002/ajmg.a.35311
- Issue published online: 18 APR 2012
- Article first published online: 11 APR 2012
- Manuscript Accepted: 4 JAN 2012
- Manuscript Received: 14 SEP 2011
- Swedish Medical Research Council
- Stockholm County Council
- Linnea and Josef Carlsson Foundation
- cat eye syndrome;
- supernumerary marker chromosome;
- chromosome 22;
- fluorescence in situ hybridization;
We have studied a family with repeated transmission of mosaicism for a supernumerary marker chromosome (SMC), giving rise to varying symptoms of the cat eye syndrome (CES) in the offspring. The frequency of the SMC was investigated using FISH with probes from the CES critical region on lymphocytes as well as buccal cells. The same probes were used to study the frequency of the SMC in spermatozoa from the father. The SMC was characterized in detail using array-CGH and was found to correspond to a symmetrical cat eye SMC type I, with two extra copies of the most proximal part of 22q11, not extending into the classical 22q11.2 deletion region. Mosaicism for the SMC was detected in 4 out of 7 family members, the father and all his three children. The degree of mosaicism varied greatly between individuals as well as between tissues, with twice as many cells with the SMC in epithelial cells compared to blood. The highest frequency (almost 50%) was found in spermatozoa from the father. There was a direct correlation between the degree of mosaicism and the symptoms, varying from no obvious symptoms to classical CES. The study confirms the occurrence of direct transmission of SMC-mosaicism in CES. The results indicate that examination of parental epithelial cells should be preferred compared to blood cells in order to exclude a recurrence risk in parents of a child with CES. Interphase FISH analysis of spermatozoa is the most sensitive method to exclude paternal germ line mosaicsm. © 2012 Wiley Periodicals, Inc.