School of Medicine, Gold Coast Campus, Griffith University, QLD 4222, Australia.
J Neurol Neurosurg Psychiatry. 2011 Dec;82(12):1351-4. doi: 10.1136/jnnp.2010.233064. Epub 2011 May 7.
Genetic susceptibility to multiple sclerosis (MS) has been recognised for many years. Considerable data exist from the northern hemisphere regarding the familial recurrence risks for MS, but there are few data for the southern hemisphere and regions at lower latitude such as Australia. To investigate the interaction between environmental and genetic causative factors in MS, the authors undertook a familial recurrence risk study in three latitudinally distinct regions of Australia.
Immediate and extended family pedigrees have been collected for three cohorts of people with MS in Queensland, Victoria and Tasmania spanning 15° of latitude. Age of onset data from Queensland were utilised to estimate age-adjusted recurrence rates.
Recurrence risks in Australia were significantly lower than in studies from northern hemisphere populations. The age-adjusted risk for siblings across Australia was 2.13% compared with 3.5% for the northern hemisphere. A similar pattern was seen for other relatives. The risks to relatives were proportional to the population risks for each site, and hence the sibling recurrence-risk ratio (λ(s)) was similar across all sites.
The familial recurrence risk of MS in Australia is lower than in previously reported studies. This is directly related to the lower population prevalence of MS. The overall genetic susceptibility in Australia as measured by the λ(s) is similar to the northern hemisphere, suggesting that the difference in population risk is explained largely by environmental factors rather than by genetic admixture.
多发性硬化症（MS）的遗传易感性已被认识多年。有关北半球 MS 的家族复发风险存在大量数据，但南半球和澳大利亚等低纬度地区的数据很少。为了研究 MS 中环境和遗传致病因素的相互作用，作者在澳大利亚三个纬度不同的地区进行了家族复发风险研究。
作者收集了昆士兰州、维多利亚州和塔斯马尼亚州三个 MS 队列的直系和旁系亲属家系谱，跨越了 15 度的纬度。来自昆士兰州的发病年龄数据用于估计年龄调整后的复发率。
澳大利亚的复发风险明显低于北半球人群的研究。澳大利亚的同胞复发风险为 2.13%，而北半球为 3.5%。其他亲属的情况也类似。亲属的风险与每个地点的人群风险成正比，因此所有地点的同胞复发风险比（λ(s)）相似。
澳大利亚的 MS 家族复发风险低于先前报道的研究。这直接与 MS 的人群患病率较低有关。澳大利亚的整体遗传易感性（以 λ(s) 衡量）与北半球相似，这表明人群风险的差异主要是由环境因素而不是遗传混合造成的。
