Sloka J S, Pryse-Phillips W E M, Stefanelli M
Faculty of Medicine (Neurology), Memorial University of Newfoundland, St. John's, NL, Canada.
Can J Neurol Sci. 2005 Feb;32(1):43-9. doi: 10.1017/s0317167100016863.
Newfoundland and Labrador, Canada, have been almost exclusively populated by immigrants from southwest England and southeast Ireland. The province's population grew largely by natural increase from 20,000 people in 1835 to half a million at present. Very little interregional migration occurred within the province. This uniquely-populated region and its subsequent founder effect provide the basis to develop models of disease prevalence.
To develop a model for the regional prevalence of multiple sclerosis (MS), accounting for settlement patterns and geographic location (latitude).
All living MS patients with confirmed addresses (438 patients) in the province were mailed a survey requesting their place of birth. Regional prevalences were calculated from a 75% rate of return of the survey. Theoretical regional prevalences were proportionally calculated from the source prevalences of southwest England, southeast Ireland, Scotland and the Channel Islands based on settlement patterns. These theoretical regional prevalences were corrected for geographical variations of latitude based on observations in the United Kingdom. Theoretical and actual regional prevalences were compared.
When actual regional prevalences were compared with theoretical prevalences, very little variation was noted, especially after correcting for variation in latitude.
A regional variation in MS prevalence is noted in the island portion of Newfoundland and Labrador. This regional variation can be modeled by using both migration patterns and latitudinal position. This model demonstrates that the prevalence of MS is influenced by both genetic and environmental contributions.
加拿大的纽芬兰与拉布拉多省的人口几乎全部来自英格兰西南部和爱尔兰东南部的移民。该省人口主要通过自然增长从1835年的2万人增长到目前的50万。省内几乎没有区域间的人口迁移。这个独特的人口构成区域及其随后的奠基者效应为疾病患病率模型的建立提供了基础。
建立一个考虑定居模式和地理位置（纬度）的多发性硬化症（MS）区域患病率模型。
向该省所有有确认地址的在世MS患者（438名患者）邮寄一份调查问卷，询问他们的出生地。根据75%的调查回复率计算区域患病率。基于定居模式，从英格兰西南部、爱尔兰东南部、苏格兰和海峡群岛的源患病率按比例计算理论区域患病率。根据英国的观察结果，对这些理论区域患病率进行纬度地理变化校正。比较理论和实际区域患病率。
当将实际区域患病率与理论患病率进行比较时，发现差异很小，尤其是在对纬度变化进行校正之后。
在纽芬兰与拉布拉多省的岛屿部分，MS患病率存在区域差异。这种区域差异可以通过迁移模式和纬度位置来建模。该模型表明，MS的患病率受到遗传和环境因素的共同影响。
