Replication of Associations of Single Nucelotide Polymor

识别衰老途径中的重要snp需要适当的表型测量，以正确反映这一过程。许多老龄化研究的传统焦点一直是生存，特别是极端长寿和百岁老人。然而，报告的寿命遗传率是适度的——男性26%，女性23%。此外，很明显，环境因素在生存中起着重要作用，因为遗传因素无法解释近几十年来人类寿命的非凡增长。与生存相比，身体机能的某些方面，尤其是走路和从坐姿站起来的速度，以及老年时的肌肉力量，似乎是高度遗传的。据报道，在国家心肺和血液研究所（NHLBI）的双胞胎研究中，8英尺步行的表现遗传率为51%，从椅子上站起来5次的时间遗传率为56%。

Identifying the important SNPs in the aging pathways requires the availability of suitable phenotype measures that properly reflect the process. The traditional focus of much aging research has been on survival, and especially on extreme longevity and centenarians. However, the reported heritability of lifespan is modest - 26% for males and 23% for females. Also, it is clear that environmental factors play a strong role in survival, as genetic factors cannot explain the extraordinary rise in human longevity experienced in recent decades. In contrast to survival, certain aspects of physical functioning, notably speed of walking and standing up from the sitting position, and muscle strength in old age, appear to be highly heritable. It has reported that the heritability of performance on an 8-foot walk in the National Heart, Lung, and Blood Institute (NHLBI) Twin Study was 51%, and time to rise from a chair five times was 56%. Analysis of the association between each of 290 SNPs and reported limitation in walking or stair climbing has been done in 2000 Epic-Norfolk women used as controls in the EPIC-Norfolk Cancer Study done in the Norfolk region of England. These SNPs were in 100 genes that were selected as being candidates for cancers. Those studied include genes linked to oxidative damage, DNA repair, insulin like growth factors and cell cycle genes, all potentially related to aging outcomes as well as cancer. The phenotype was defined through responses of participants to the physical function domain of the Short-Form 36 questionnaire. Using samples from over 2000 additional women from the control group of that study, this work will attempt to replicate initial association findings by testing the link between 11 specific SNPs and reported mobility performance. Genotyping is now nearly complete and analyses are under way.