POLD1 and hyperinsulinemic hypoglycemia, familial, 4: First, although SBS_D-positive samples lacked the characteristic features of POLD1 or DNA repair deficiency—such as hypermutation and low genome aberration (Figure 4b)—they exhibited strikingly higher indel burden compared to SBS_D-negative samples (1.3-fold increase; q-value of 2.50 × 10−12 after adjusting for known covariates), whereas negligible differences were observed for SBS burden and genome aberration (Figure 5a).