Monosomy 21 Seen in Live Born Is Unlikely to Represent True Monosomy 21: A Case Report and Review of the Literature
Figure 2
The monosomy 21 cell line is not shown. (a) G-banded fibroblast karyotype showing the ring chromosome 21. (b) Metaphase FISH of cultured fibroblasts using the ETV6/RUNX1 probe set indicating the presence of a double ring, that is, 1 copy of RUNX1 on the normal chromosome 21 and 2 copies on the double ring chromosome 21. (c) Chromosome microarray using the Illumina HumanCoreExome v1 performed on cultured fibroblast showing a copy number () that is consistent with the presence of a monosomic cell line and cell lines with a ring and double ring chromosome 21. The 8.8 Mb terminal deletion is also indicated. The B-allele frequency also confirms the mosaic nature of this finding.
