Understanding Germline and Somatic Mutations

Somatic Mutations

Somatic mutations are acquired mutations. These mutations may only be present in a patient’s tumor and can be identified with a tumor sample.

Germline Mutations

Germline mutations are inherited from a person’s parent. These mutations are present in every cell of the body and can be identified with a blood or buccal/saliva sample

Tumor BRCA testing will detect somatic (isolated to the tumor) and germline (inherited) BRCA1/2 mutations to help inform PARP inhibitor treatment decision making. In order to accurately determine whether a BRCA1/2 mutation identified on tumor testing is germline or somatic, follow up hereditary cancer testing should be considered.

Myriad Products that Assess Tumor BRCA1/2 Status

Myriad myChoice HRD

Treatment Decision: PARP inhibitors*, DNA-damaging chemotherapy
Assay: Tumor BRCA1 and BRCA2 assessment, Genomic Instability Status to determine whether homologous recombination deficiency is present in the tumor
Sample Type: Tumor (FFPE)
Mutations Identified: Tumor mutations (inclusive of germline and somatic)†


* BRACAnalysis CDx has been approved by the FDA to inform treatment decisions related to Lynparza and Zejula in patients with ovarian cancer. myRisk, myChoice HRD and BRACAnalysis have not been approved by the FDA.

†Follow-up testing on a blood or saliva sample is recommended to determine whether a tumor BRCA1/2 mutation is germline (inherited) or somatic (isolated to the tumor).