Figure 2

Patterns of Allelic Ratios (AR). Each point (blue dot) represents the AR for one SNP mapped to its relative physical position along the length of the chromosome from the p-terminus (left) to the q-terminus (right). The vertical white rectangles indicate the position of the centromeres, which lack SNP probes. (A) In Chr:5 from sample C92, three 'bands' are evident in a disomic chromosome; ARs of 0 and 1 represent homozygous signals (AA or BB) while an AR of ~0.5 represents an equal contribution from both alleles (AB). (B) Two small deletions in the p-arm of disomic Chr:1 in C79 produce characteristic patterns that lack heterozygote signal and show some bleeding of the single-copy homozygotic signal (one A or B allele) toward the middle. (C) The copy-number neutral LOH seen on the long arm of Chr:8 in C156 also lacks heterozygous signal, but does not show inward bleeding. (D) A trisomic pattern for Chr:10 in C82 is characterized by heterozygotic ratios near 0.33 (AAB) and 0.67 (ABB), rather than at 0.5. (E) An unbalanced tetrasomy pattern for Chr:10 in C72, reflecting heterozygote ratios of 0.25 (AAAB) and 0.75 (ABBB), is seen on the short arm, but the ARs shift to an unbalanced pentasomic (ABBBB) and then a trisomic pattern (ABB) near the mid-point of the long arm.