Genomic technologies have enabled the sequencing of childhood cancer patients to investigate genetic predisposition. This review compares 6 studies of selected cohorts of childhood cancer patients reporting clinically relevant pathogenic germline variants in a broad spectrum of genes associated with susceptibility to both adult and paediatric cancers. We identified differences in the reported incidence of pathogenic or likely pathogenic germline variants, and incompletely overlapping gene sets interpreted as clinically relevant, with further research required to investigate the role of variants in genes associated with adult onset cancers. (By Dianne Sylvester, https://jmg.bmj.com/content/early/2018/10/03/jmedgenet-2018-105488 )