Figure 2.

Figure 2.

SNP array example of a heterozygous deletion and a heterozygous duplication

Each dot represents the B-allele frequency and total fluorescence intensity for a single SNP. Predicted genotypes of SNPs as measured by B-allele frequency are shown in red font. The lower-case letters (a-d) at the top and bottom of the diagram identify segments of an SNP array that demonstrate the B-allele frequency and intensity signals typical for: (a) a normal diploid region with identified genotypes for each SNP of AA, AB, or BB; (b) a heterozygous deletion in which the AB genotype is absent and only the genotypes B and A are identified at each SNP, and the decrease in intensity reflects the decreased number of alleles; (c) a normal diploid region; and (d) a heterozygous duplication with identified genotypes for each SNP of AAA, AAB, ABB, or BBB, and the increase in intensity reflects the greater number of alleles.

From: Educational Materials — Genetic Testing: Current Approaches

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