MacGregor A J, Antoniades L, Matson M, Andrew T, Spector T D
Twin Research and Genetic Epidemiology Unit, St. Thomas' Hospital, London, UK.
Arthritis Rheum. 2000 Nov;43(11):2410-6. doi: 10.1002/1529-0131(200011)43:11<2410::AID-ANR6>3.0.CO;2-E.
To assess the genetic contribution to radiographic hip osteoarthritis (OA) by measuring the distribution of disease features in monozygotic (MZ) and dizygotic (DZ) twins.
A population-based, cross-sectional study was conducted of 135 MZ and 277 DZ healthy female twin pairs, 50 years of age and older, who were recruited into the St. Thomas' UK Adult Twin Registry. Pelvic radiographs were read by a single observer who was blinded to the pairing and zygosity of the twins. The films were assessed for overall OA grade using a modification of the Kellgren and Lawrence scheme, and assessed for individual radiographic features.
There was evidence of significant familial clustering for grade I and grade II OA changes, with an excess concordance in MZ twins compared with DZ twins, suggesting a genetic effect. The MZ versus DZ excess was also apparent for those classified as having more severe disease, although the number of pairs with these disease features was small. Familial clustering attributable to genetic factors was evident for joint space narrowing of <2.5 mm. Familial, but not genetic, clustering was seen for subchondral sclerosis. The number of pairs concordant for definite osteophytes in the sample was too low to assess this feature alone. These results translate into a significant heritability of 58% for OA overall and 64% for joint space narrowing. The heritability estimates decreased a little when the potential confounding influences of age, body mass index, and hip bone density were taken into account.
Genetic factors have a significant contribution to OA at the hip in women and account for approximately 60% of the variation in population liability to the disease.
通过测量单卵双胞胎（MZ）和双卵双胞胎（DZ）中疾病特征的分布，评估遗传因素对髋关节骨关节炎（OA）影像学表现的影响。
对135对MZ和277对DZ健康女性双胞胎进行了一项基于人群的横断面研究，这些双胞胎年龄在50岁及以上，均纳入了英国圣托马斯成人双胞胎登记处。骨盆X光片由一名对双胞胎的配对情况和卵性不知情的观察者进行判读。采用改良的凯尔格伦和劳伦斯分级法评估X光片的总体OA分级，并评估各个影像学特征。
有证据表明I级和II级OA改变存在显著的家族聚集性，与DZ双胞胎相比，MZ双胞胎的一致性更高，提示存在遗传效应。对于那些被归类为患有更严重疾病的双胞胎，MZ与DZ之间的差异也很明显，尽管具有这些疾病特征的双胞胎对数较少。关节间隙狭窄小于2.5mm时，可明显看出遗传因素导致的家族聚集性。对于软骨下硬化，可见家族聚集性，但非遗传聚集性。样本中明确有骨赘的双胞胎对数过少，无法单独评估这一特征。这些结果表明，OA总体的遗传度为58%，关节间隙狭窄为64%。当考虑年龄、体重指数和髋部骨密度的潜在混杂影响时，遗传度估计值略有下降。
遗传因素对女性髋关节OA有显著影响，约占人群中该疾病易感性变异的60%。
