Detection of complete homozygosity of the short arm including a small deletion in the chromosome 9. The B allele frequency (BAF) and Log R ratio (LRR) plots of SNP calls on chromosome 9 (idiogram displayed on the bottom of the diagram) using various quantities of DNA for the array are shown. The BAF in the short arm are 1 or 0, except the small region of deletion, indicating homozygosity of the entire short arm. The deleted region is indicated with an arrow on the top of the figure. The LRR is clearly absent from 0, which would indicate two copies of the chromosome are present. It is apparent that as the DNA quantity decreases, the level of noise and scattering increases in both plots. However, the region of deletion is clearly identifiable in all arrays.