Table 18-2: Frequencies of SNP rs9272426 Genotypes in HLA-DQA1 of the MHC Locus     for People from Tuscany, Italy

Genotypes

A/A

A/G

G/G

Sum

Observed number

17

55

12

    84

Observed frequency

0.202

0.655

0.143

      1

Expected frequency

0.281

0.498

0.221

      1

Expected number

23.574

41.851

18.574

    84

(Observed − expected)2/expected

1.833

4.131

2.327

8.29

Source: International HapMap Project (www.hapmap.org).