Arterial properties in relation to genetic variations in the adducin subunits in a white population

Background: Adducin is a membrane skeleton protein, which consists of either α- and β- or α- and γ-subunits. We investigated whether arterial characteristics might be related to the genes encoding ADD1 (Gly460Trp-rs4961), ADD2 (C1797T-rs4984), and ADD3 (IVS11+386A>G-rs3731566). Methods: We randomly recruited 1,126 Flemish subjects (mean age, 43.8 years; 50.3% women). Using a wall-tracking ultrasound system, we measured the properties of the carotid, femoral, and brachial arteries. We studied multivariate-adjusted phenotype-genotype associations, using a population- and family-based approach. Results: In single-gene analyses, brachial diameter was 0.15 mm (P = 0.0022) larger, and brachial distensibility and cross-sectional compliance were 1.55 × 10^-3/kPa (P = 0.013) and 0.017 mm ²/kPa (P = 0.0029) lower in ADD3 AA than ADD3 GG homozygotes with an additive effect of the G allele. In multiple-gene analyses, the association of brachial diameter and distensibility with the ADD3 G allele occurred only in ADD1 GlyGly homozygotes. Otherwise, the associations between the arterial phenotypes in the three vascular beds and the ADD1 or ADD2 polymorphisms were not significant. In family-based analyses, the multivariate-adjusted heritability was 0.52, 0.38, and 0.30 for brachial diameter, distensibility, and cross-sectional compliance, respectively (P <0.001). There was no evidence for population stratification (0.07 ≤ P ≤ 0.96). Transmission of the mutated ADD3 G allele was associated with smaller brachial diameter in 342 informative offspring (-0.12 ± 0.04 mm; P = 0.0085) and in 209 offspring, who were ADD1 GlyGly homozygotes (-0.14 ± 0.06 mm; P = 0.018). Conclusions: In ADD1 GlyGly homozygotes, the properties of the brachial artery are related to the ADD3 (A386G) polymorphism, but the underlying mechanism needs further clarification.