Mutations described as germline are replicated in every cell of the body. This reflects their origin in the DNA within germinal cells (eggs or sperm) and the resulting transmission to progeny at conception. Inherited (germline) BRCA mutations account for the majority of familial ovarian cancer.REF
Genetic alteration acquired by a cell that can be passed to the progeny of the mutated cell in the course of cell division. These alterations can (but do not always) cause cancer or other diseases. Somatic mutations are non-heritable.
BRCA mutations detected in DNA extracted from a sample of tumour tissue can be either germline or somatic.
A subsequent blood test can determine whether the mutation is germline or somatic.REF
DNA extracted from a blood sample can be used to determine the presence of germline BRCA mutation(s).