Objective

To estimate the genetic contribution to doctor-diagnosed hand osteoarthritis (OA).

Methods

Using data from the Swedish Twin Registry and National Patient Register, we conducted a 20-year population-based longitudinal cohort study including 59,970 twins aged 35 years or older. We studied inpatient and outpatient doctor-diagnosed hand OA using ICD-10 codes from 1997 until 2016, including both the distal/proximal interphalangeal (DIP/PIP) joints and/or the first carpometacarpal (CMC-1) joints. We calculated intra-pair correlation, estimated the heritability (i.e., the percentage variation in hand OA that can be explained by genetic factors) as well as a genetic risk.

Results

Among 59,970 included persons, 936 had a hand OA diagnosis registered during the study period. The heritabilities of hand OA (any joint), CMC-1 OA and DIP/PIP OA were ∼87%, 86% and 48%, respectively, yet the two latter should be interpreted with care due to low numbers. Hand OA in any joint in both twins in a pair occurred more frequently in identical twins (54/554 = 9.7%, intra-pair correlation = 0.54, 95% CI = 0.44–0.63) than in fraternal twins (18/1,246 = 1.4%, intra-pair correlation = 0.10, 95% CI = −0.01–0.22). Identical twins who were diagnosed with hand OA in any joint had a far higher risk than fraternal twins with hand OA to also have their co-twin diagnosed with hand OA in any joint (Hazard Ratio = 6.98, 95% CI = 3.08–15.45).

Conclusion

The genetic contribution to hand OA is high and likely varying between 48% and 87%. Potential differential heritability by hand OA phenotypes should be further explored.

中文翻译：

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手部骨关节炎的遗传贡献

客观的

估计遗传对医生诊断的手骨关节炎 (OA) 的贡献。

方法

利用瑞典双胞胎登记处和国家患者登记处的数据，我们进行了一项为期 20 年的基于人群的纵向队列研究，包括 59,970 名 35 岁或以上的双胞胎。从 1997 年到 2016 年，我们使用 ICD-10 代码研究了住院和门诊医生诊断的手部 OA，包括远端/近端指间 (DIP/PIP) 关节和/或第一腕掌 (CMC-1) 关节。我们计算了配对内相关性，估计了遗传力（即可以由遗传因素解释的手部 OA 的百分比变异）以及遗传风险。

结果

在纳入的 59,970 人中，936 人在研究期间登记了手部 OA 诊断。手部 OA（任何关节）、CMC-1 OA 和 DIP/PIP OA 的遗传率分别约为 87%、86% 和 48%，但由于数字较低，应谨慎解释后两者。一对双胞胎中任何关节的手部 OA 在同卵双胞胎中发生的频率更高（54/554 = 9.7%，对内相关性 = 0.54，95% CI = 0.44-0.63）比异卵双胞胎（18/1,246 = 1.4 %，对内相关 = 0.10，95% CI = -0.01–0.22）。在任何关节被诊断出患有手部 OA 的同卵双胞胎的风险远高于患有手部 OA 的异卵双胞胎在任何关节中也被诊断出患有手部 OA 的风险（风险比 = 6.98，95% CI = 3.08–15.45） .

结论

手部 OA 的遗传贡献率很高，可能在 48% 和 87% 之间变化。应进一步探索手 OA 表型的潜在差异遗传力。