Figure 6

SNP array analysis of cases 7 and 8. A) SNP cluster plots of individual SNPs. Green, red and black dots represent controls with a BB, AB and AA genotype respectively. The pink and blue dots represent the genotypes of the mother and father. The yellow dots indicate the genotype of case 7 in cells with the duplication, while the orange dots give the genotype of the normal cells of the fetus. The SNPs shown are located within the paternal duplication. The plots indicate that paternal heterozygous SNPs in the duplicated region do not show transmission of both paternal alleles, but instead revealed a duplication of one of the paternal alleles. This suggests the duplication originated during postzygotic mitosis or meiosis II. B) The B allele frequency graph of chromosome 11 shows abnormal heterozygous values without complete loss of heterozygosity in the deleted segment in case 8. No additional haplotypes are found in the regions surrounding the deletion. This rules out the possibility of a trisomy rescue and indicates the deletion originated during postzygotic mitosis or meiosis II.