To further explore the robustness of the age effect on clonal mosaicism, additional analyses were performed with each of the seven studies having more than 1,000 subjects over 50 years old (using both blood and saliva/buccal samples). Only the age effect was significant (p=8 × 10−16) in a combined logistic regression of mosaic status on study, sex, DNA source, ethnicity and smoking status (separately testing either ‘ever’ smoker or ‘never’ smoker). When only controls from these studies were analyzed together, the age effect remained highly significant (p=7 × 10−11). We also analyzed each study separately, with age and the case status specific to each study. A meta-analysis shows a highly significant effect of age (Figure 6), which is very robust to differences in both study and subject characteristics.
