Multilocus Family-Based Association Analysis of Seven Candidate Polymorphisms with Essential Hypertension in an African-Derived Semi-Isolated Brazilian Population

Table 6

Analysis of haplotypic effects (G-350A/C825T) on blood pressure-related phenotypes.

Trait	N	Haplotypes		Haplotypic effects		LD measures		LR test
		G(-350A)	C825T	OR (95% CI)	P value	𝐷^′	𝑅^2	𝜒^2 (df)	P value
Hypertension	384	G	C	reference	—	0.40	0.10	5.29 (3)	0.152
		G	T	0.586 (0.358–0.958)	0.033
		A	C	0.591 (0.336–1.040)	0.068
		A	T	0.865 (0.451– 1.659)	0.661
				Δ (95% CI)	P value
SBP (mmHg)	384	G	C	reference	—	0.40	0.10	7.04 (3)	0.071
		G	T	−2.208 (−6.734–2.318)	0.339
		A	C	−0.482 (−5.95–4.986)	0.862
		A	T	−1.361 (−7.39–4.67)	0.658
				Δ (95% CI)	P value
DBP (mmHg)	384	G	C	reference	—	0.40	0.10	2.82 (3)	0.420
		G	T	−1.247 (−3.878–1.383)	0.352
		A	C	−2.328 (−5.447–0.792)	0.143
		A	T	−1.996 (−5.596–1.605)	0.277

N: sample size. OR: odds ratio. EH: essential hypertension. LD: linkage disequilibrium. LR: likelihood ratio. df: degrees of freedom. Δ: expected linear increment in the trait per additional copy of the haplotype (in mmHg). All results refer to the additive model of analysis and are adjusted for age, gender, and BMI. Analyses were also performed under both dominant and recessive models of action, yielding qualitatively analogous results (data not shown). The overall proportion of haplotypes G-350A/C825T in the studied population was 0.197, 0.499, 0.196, and 0.108 for haplotypes GC, GT, AC, and AT, respectively. For the hypertension status, haplotypic frequencies for hypertensive/normotensive participants were as follows: GC: 0.248/0.186, GT: 0.443/0.523, AC: 0.195/0.190 and AT: 0.114/0.10.