How to Cite this Article: Huang B, Pearle P, Rauen KA, Cotter PD. 2012. Supernumerary marker chromosomes derived from chromosome 6: Cytogenetic, molecular cytogenetic and array CGH characterization. Am J Med Genet Part A. 158A:1568–1573.
Supernumerary marker chromosomes derived from chromosome 6: Cytogenetic, molecular cytogenetic, and array CGH characterization†
Article first published online: 25 MAY 2012
Copyright © 2012 Wiley Periodicals, Inc.
American Journal of Medical Genetics Part A
Volume 158A, Issue 7, pages 1568–1573, July 2012
How to Cite
Huang, B., Pearle, P., Rauen, K. A. and Cotter, P. D. (2012), Supernumerary marker chromosomes derived from chromosome 6: Cytogenetic, molecular cytogenetic, and array CGH characterization. Am. J. Med. Genet., 158A: 1568–1573. doi: 10.1002/ajmg.a.35385
- Issue published online: 18 JUN 2012
- Article first published online: 25 MAY 2012
- Manuscript Accepted: 5 MAR 2012
- Manuscript Received: 5 DEC 2011
- NIH. Grant Number: HD048502
- marker chromosome;
- array CGH;
- chromosome 6;
Supernumerary marker chromosomes (SMC) are relatively common in prenatal diagnosis. As the clinical outcomes vary greatly, a better understanding of the karyotype–phenotype correlation for different SMCs will be important for genetic counseling. We present two cases of prenatally detected de novo, small SMCs. The markers were present in 80% of amniocyte colonies in Case 1 and 38% of the colonies in Case 2. The SMCs were determined to be derived from chromosome 6 during postnatal confirmation studies. Although the sizes and the chromosomal origin of the SMCs in these two cases appeared to be similar, the clinical outcomes varied. The clinical manifestations observed in Case 1 included small for gestational age, feeding difficulty at birth, hydronephrosis, deviated septum and dysmorphic features, while the phenotype is apparently normal in Case 2. Array comparative genomic hybridization (CGH) was performed and showed increase in dosage for approximately 26 Mb of genetic material from the proximal short and long arms of chromosome 6 in Case 1. Results of array CGH were uninformative in Case 2, either due to mosaicism or lack of detectable euchromatin. The difference in the clinical presentation in these two patients may have resulted from the difference in the actual gene contents of the marker chromosomes and/or the differential distribution of the mosaicism. © 2012 Wiley Periodicals, Inc.