Table 4.
Haplotype analysis for two CRY1 SNPs in CH patients and controls.
| Haplotype | Controls % (n) | CH Patients % (n) | χ2 (df=2) | p-value | pc-value |
|---|---|---|---|---|---|
| G-G‡ | 34.8 (471) | 36.4 (444) | 0.67 | 0.414 | 0.757 |
| C-G | 23.2 (314) | 27.3 (333) | 5.93 | 0.015 | 0.024* |
| C-A | 22.0 (298) | 19.3 (236) | 2.91 | 0.088 | 0.184 |
| G-A | 20.0 (271) | 17.0 (207) | 3.77 | 0.052 | 0.107 |
‡Reference haplotype (G-G) corresponds to major allele of each CRY1 single nucleotide polymorphism (SNP) where rs2287161 is in position 1, and rs8192440 in position 2. CH, cluster headache; χ2, chi-square; df, degrees of freedom; pc, corrected p-value after permutation testing (10,000 permutations); *pc-value < 0.05 was considered significant.