Women diagnosed with breast cancer at a very early age (≤30 years) are more likely to have a genetic predisposition.  Pathogenic variants in BRCA1, BRCA2 and TP53 are often associated with an early onset of disease. However, the association is unclear for other breast cancer associated genes. Here, we assessed the contribution of pathogenic variants in BRCA1, BRCA2, TP53 and eight other breast cancer associated genes in 379 women diagnosed with breast cancer at the age of ≤30 years. The vast majority of pathogenic variants found were in BRCA1, BRCA2, and TP53 (n=132), whereas only ten actionable pathogenic variants were detected in other genes.  This indicates that there is little benefit for testing beyond these three genes in young women diagnosed with breast cancer.  (By Elke van Veen, https://jmg.bmj.com/content/early/2021/03/23/jmedgenet-2020-107347 )