It does not appear that one gene is responsible for MS.

VOA: special.2009.01.06

It does appear that it's harder to lose the weight below the waist, but there is some mixed research on that as well.

但腰部以下的脂肪似乎更难减掉,关于这点也有一些相应的研究

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选