Table 4.

Frequency analysis of the 6 discriminating alleles.

A. Frequencies and odds ratios
	Allele	GWI frequency	Control frequency	Estimated odds ratio ($\widehat{\omega }$)	ln($\widehat{\omega }$)
1	DQB1*02:02	0	0.0625	0.046a	− 3.078
2	DPB1*06:01	0.007576	0.0625	0.114	− 2.167
3	DRB1*13:02	0.0379	0.125	0.276	− 1.289
4	DRB1*08:11	0	0.0312	0.0792a	− 2.535
5	DRB1*01:01	0.0682	0.1562	0.395	− 0.927
6	DPB1*01:01	0.0303	0.0625	0.469	− 0.758

B. Percent of participants per group and allele
	Allele	GWI	Control
1	DQB1*02:02	0	12.5
2	DPB1*06:01	1.5	12.5
3	DRB1*13:02	7.6	25
4	DRB1*08:11	0	6.3
5	DRB1*01:01	13.6	18.8
6	DPB1*01:01	6.1	12.5

^aThe odds ratio was estimated after adding 0.5 to all counts to avoid taking the logarithm of zero. This procedure underestimates the true effect.