Association of a (TTTA)_n microsatellite and a TCT del/ins polymorphisms in the aromatase gene (CYP19) with hip fracture risk in Mexican postmenopausal women

Abstract

A (TTTA)_n polymorphism in the aromatase gene has been studied in relation to bone mineral density (BMD). The low number of TTTA repeats has been associated with low BMD and fracture risk. The aim of this study was to search for associations of TTTA copy number with hip fracture and lumbar spine osteoporosis in Mexican peri and postmenopausal women. The allele with seven repeats was present in the two reported versions, with or without a TCT deletion upstream of the microsatellite (A1 and A2, respectively). After adjustment by confounders, the A1 allele and the A1A1 genotype were significantly associated with an elevated risk of fracture (p = 0.034, OR = 3.2 [95% CI, 1.09–9.41] and p = 0.019, OR = 2.26 [95% CI, 1.14–4.49], respectively) and the A2 allele was associated with protection of hip fracture (p = 0.04, OR = 0.48, [95% CI, 0.22–1.05]) as the A2A2 genotype (p = 0.048, OR = 0.29 [95% CI, 0.06–1.16]). The analysis allowed us to defining the usefulness of the (TTTA)_n polymorphism in the aromatase gene as an indicator of hip fracture risk in Mexican population.

Chinese abstract

芳香化酶基因中（TTTA）n的多态性与骨密度（BMD）之间的关系已经被研究。低TTTA重复序列与低骨密度和高骨折风险相关。本研究的目的是研究TTTA复制的数量与墨西哥围绝经和绝经妇女髋部骨折以及腰椎骨质疏松的相关性。重复7遍的等位基因出现在其上游或没有TCT缺失的两种微卫星中（分别是A1和A2）。校正混杂因素后，A1等位基因和A1A1基因型与骨折风险呈显著相关。(分别是p=0.034, OR=3.2 [95% CI, 1.09–9.41] ；p=0.019, OR=2.26 [95% CI, 1.14–4.49])；A2等位基因与髋部骨折的保护呈相关性(p=0.04,OR=0.48, [95% CI, 0.22–1.05]) 而A2A2基因型为 (p=0.048, OR=0.29 [95% CI, 0.06–1.16])。通过分析我们可以认为芳香化酶基因中的（TTTA）n多态性是预测墨西哥人群髋部骨折风险的一个有用的指标。

Keywords:

• Aromatase polymorphisms
• hip fracture
• osteoporosis
• postmenopausal women

Declaration of interest

The authors have no conflicts of interest to disclose. This study was supported by: Consejo Nacional de Ciencia y Tecnología, SALUD-2007-C01-69706.