Figure 1

The sketch of genotyping calling. The points shown in 'x' represent no-calls due to the failure of being assigned to any clusters of genotype unequivocally. When the data points lie between the cluster of homozygotes of minor alleles (AA) and that of heterozygotes (Aa), the real calls could be AA or Aa, corresponding to Scenario I and Scenario II. When the data points lie between the cluster of heterozygotes (Aa) and that of homozygotes of major alleles (aa), the real calls could be Aa or aa, corresponding to Scenario III and Scenario IV.