Table 3.
Haplotype Analysis for 3 HCRTR2 SNPs in CH Patients and Controls
| Haplotype | Control | CH Patients | χ2 (df = 2) | P Value | Ppermut Value | ||
|---|---|---|---|---|---|---|---|
| n | % | n | % | ||||
| T‐G‐G † | 640 | 55.4 | 606 | 58.6 | 2.367 | .1239 | |
| G‐G‐G | 297 | 25.7 | 224 | 21.6 | 4.932 | .0264 | .1160 |
| T‐A‐A | 158 | 13.7 | 148 | 14.3 | 0.161 | .6881 | |
| G‐G‐A | 41 | 3.5 | 42 | 4.1 | 0.482 | .4873 | |
| T‐G‐A | 9 | 0.8 | 10 | 0.9 | 0.116 | .7334 | |
| G‐A‐A | 8 | 0.6 | 2 | 0.2 | 2.545 | .1107 | |
| T‐A‐G | 3 | 0.3 | 2 | 0.2 | 0.101 | .7506 | |
χ2, chi‐square; CH, cluster headache; df, degrees of freedom; Ppermut value, P value after test with 10,000 permutations.
†
Reference haplotype (T‐G‐G) corresponds to wild‐type allele of each HCRTR2 single nucleotide polymorphism (SNP) where rs3122156 is in position 1, rs2653342 in position 2, and rs2653349 in position 3.