ABSENCE OF LINKAGE BETWEEN VO2MAX AND ITS RESPONSE TO TRAINING WITH MARKERS SPANNING CHROMOSOME-22

An extensive search for linkage between DNA markers and the response o f (V) over dot O-2max to training has recently been launched in the HE RITAGE Family Study. This is the first report on a genome-wide search strategy to locate chromosomal regions and positional candidate genes for cardiorespiratory endurance phenotypes. Linkage between seven mark ers spanning chromosome 22 spaced approximately 10 cM apart (D22S264, D22S274, D22S301, D22S304, D22S421, IL2RB, and PDGFB) and (V) over dot O-2max at baseline, as well as its response to endurance exercise tra ining, was examined using the sib-pair linkage method. Markers were ge notyped in at least 210 sib-pairs derived from 128 adult brothers (25 +/- 6 yr; mean +/- SD) and 138 sisters (24 +/- 6 yr) from 86 Caucasian families. (V) over dot O-2max, maximal heart rate, and maximal oxygen pulse were measured during stationary cycle tests before and after a standardized 20-wk endurance training program. On average, the initial (V) over dot O-2max was 2654 +/- 767 mL.min(-1) while training increa sed (V) over dot O-2max significantly by 430 +/- 239 mL.min(-1) or 16% (P < 0.0001). The (V) over dot O-2max response was adjusted for age a nd initial (V) over dot O-2max. No evidence of linkage was found betwe en any of these markers on chromosome 22 and (V) over dot O-2max or it s trainability.