Prevalence of PALB2 mutation c.509_510delGA in unselected breast cancer patients from Central and Eastern Europe

Inherited mutations in PALB2 are known to be associated with increased breast cancer risk. We aimed to investigate the prevalence and risk association of a recurrent PALB2 mutation, c.509_510delGA, among 3,924 unselected breast cancer patients from Belarus, Russia or Germany. High-resolution melting analyses and direct sequencing identified the c.509_510delGA allele in 3/1,008 (0.3 %) German breast cancer patients, 2/994 (0.2 %) Russian breast cancer patients and 5/1,922 (0.3 %) Byelorussian breast cancer patients. Breast tumours were mainly estrogen receptor positive and included both ductal and lobular histology. Only one of the ten patients had a first-degree family history of breast cancer. The mutation was not detected in 2,827 healthy females from the same populations, confirming the association of PALB2*c.509_510delGA with breast cancer risk (p = 0.007). These data indicate that the PALB2*c.509_510delGA mutation is prevalent in about 1 in 400 breast cancer patients from Central and Eastern Europe, and the low occurrence of familial clustering is consistent with a moderate penetrance of this mutation.