Constitutional mosaicism for a BRCA2 mutation as a cause of early-onset breast cancer

We report on a breast cancer patient with constitutional somatic mosaicism of aBRCA2 mutation.BRCA2 mutation c.9294C>G, p.(Tyr3098Ter) was detected in 20% of reads in DNA extracted from peripheral blood using next-generation sequencing (NGS). TheBRCA2 mutation was subsequently observed at similar levels in normal breast tissue, adipose tissue, normal right fallopian tube tissue and ovaries of the patient, suggesting that this mutation occurred early in embryonic development. This is the first case to report constitutional mosaicism for aBRCA2 mutation and shows thatBRCA2 mosaicism can underlie early-onset breast cancer. NGS forBRCA1/2 should be considered for patients whose tumors harbor aBRCA1/2 mutation and for individuals suggestive of genetic predisposition but without a family history of HBO.
Source: Familial Cancer - Category: Cancer & Oncology Source Type: research