Inheritance of a Ring Chromosome 21 in a Couple Undergoing In Vitro Fertilization (IVF): A Case Report
Location and extent of the loss of genomic DNA on the ring chromosome 21. An ideogram of chromosome 21 and the genes that are located within the deleted region of the ring chromosome 21 are shown. Entries in the DECIPHER database (deletions are shown in red, and duplications are shown in blue), OMIM genes, and RefSeq genes are taken from the UCSC genome browser http://genome.ucsc.edu/ (Human Mar. 2006 (NCBI36/hg18) assembly). The deletion cases in DECIPHER have proximal breakpoints at positions 40.16 Mb (case 253457), 43.99 Mb (case 253454), and 45.35 Mb (case 2126), and that reported by Bertini et al.  (not shown above) starts at 43.50 Mb; all four deletions end at 46.89 Mb. The COL6A1, COL6A2, and PCNT genes are shown in red boxes. The horizontal red line with arrow heads denotes the extent of the chromosome 21 loss detected in the case reported here.