Fig. 2: Analysis of somatic mutations and their signatures in HSPC colonies.

a, Scatter plot of somatic SNVs per colony against age, with the red line and area representing the normal mutation rate and 95% CI from six normal donor samples. b, 95% CI of normal mutation rates estimated from other studies and ours. c, Three distinct SNV signatures deduced from the sequencing of 1,032 colonies. SBS-C is closely related, with a 90% cosine similarity, to the SBS-MM1 signature²². d, A stacked bar chart illustrating the frequency distribution of SBS1, SBS5 and SBS-C signatures across all SNVs in individual colonies. e, Phylogenetic trees for PID0003 and PID0004, incorporating mutation signatures. SBS-C is apparent only in mutations acquired later in the patients’ lives.