. 2012 Apr 18;109(19):7391–7396. doi: 10.1073/pnas.1202484109

Table 2.

Statistics for 2 × 2 contingency tables of the variables: Mitochondrial haplogroup (M9, non-M9) or variant 3394 (C, T) and altitude (high, low)

Variable tested	Dataset^*	Sample size	Pearson χ²-value	P value		OR	95% Confidence intervals
Variable tested	Dataset^*	Sample size	Pearson χ²-value	Asymptotic	Exact	OR	95% Confidence intervals
Haplogroup	1	353	34.0	<0.0001	7.39 E-09	12.5	4.42	35.3
	2	1,929	274.7	<0.0001	2.71 E-41	19.5	12.3	30.8
	3	11,302	1173.3	<0.0001	4.93 E-129	23.7	18.4	30.5
Variant 3394	1	353	35.77	<0.0001	1.43 E-09	13.1	4.6	36.9
	2	1,929	268.48	<0.0001	1.27 E-40	17.9	11.5	27.8
	3	11,302	896.7	<0.0001	5.66 E-106	14.7	11.7	18.4
	4	11,302	1004.8	<0.0001	4.83 E-117	16.54	13.2	20.7
	5	11,302	1272.8	<0.0001	2.76 E-144	21.88	17.4	27.6

*Dataset 1: Tibetan sample 1 vs. SW China Han; Dataset 2: Tibetan samples 1 + 2 vs. SW China Han, Taiwan Han, and southern California Han; Dataset 3: Tibetan samples 1 + 2 + Zhao et al. (34) Tibetans vs. SW China Han, Taiwan Han, southern California Han, and NCBI complete mtDNA sequences (last updated 05/17/2010), excluding five M9 sequences from Tibet (34); Dataset 4: Tibetan samples 1 + 2 + Zhao et al. (34) Tibetans + 10 C4a samples from Daccan plateau in southern India vs. SW China Han, Taiwan Han, southern California Han, and NCBI complete mtDNA sequences (last updated 05/17/2010), excluding five M9 sequences from Tibet (34); Dataset 5: Tibetan samples 1 + 2 + Zhao et al. (34) Tibetans + 10 C4a samples from Daccan plateau in southern India + two C4a samples from northern India, + 21 M9 samples from northern India vs. SW China Han, Taiwan Han, southern California Han, and NCBI complete mtDNA sequences (last updated 05/17/2010), excluding five M9 sequences from Tibet (34).