Figure 4: Sex differences in erythrocyte phosphatidylinositol
glycan class A (PIG-A ) mutant frequency for 5 publications. Solid
bars represent the mean mutant frequency and error bars show standard
deviation. The white numbers on each bar represent the number of healthy
participants in each category.
As DNA damage and subsequent mutations can accumulate with age due to
age-related reductions in DNA repair capacity and the lifelong
accumulation of such DNA damage, the potential impact of age has been
investigated by several research groups. A significant association
between older age and increased mutant frequencies was found in three
cohorts interrogating erythrocytes (Dertinger et al., 2015; Haboubi et
al., 2019; Lawrence et al., 2020) and one interrogating reticulocytes
(Torous et al., 2020), whilst other research groups either found minimal
or no correlation with age. However, when Cao and colleagues measured
the utility of this assay to identify mutagenicity in a cohort
occupationally exposed to polycyclic aromatic hydrocarbons, the
statistical analysis performed accounted for the impact of age on mutant
frequency, suggesting there may be an age effect in this ethnic Chinese
population (Cao et al., 2021). We may expect a correlation between
mutation accumulation and age, with previous publications demonstrating
an increased in single-base substitution mutational burden with age
(Robinson et al., 2021). However, the studies published to date do not
include a sufficient number of participants at either end of the age
spectrum to fully inform us whether an effect exists on an
epidemiological scale.