Reliability and stability of individual differences in gene expression

Studying the causes and correlates of natural variation in gene expression in healthy populations assumes that individual differences in gene expression can be reliably and stably assessed across time. However, this is yet to be established. We examined 4-hour test-retest reliability and 10 month test-retest stability of individual differences in gene expression in 10 12-year-old children. Blood was collected on four occasions: 10am and 2pm on day one and 10 months later at 10am and 2pm. Total RNA was hybridised to Affymetrix-U133 plus 2.0 arrays.