In the field of cancer genetics, two types of genetic mutations are commonly encountered. Somatic mutations are by far the commonest, and arise from the interaction of genes (Nature) and the environment (Nurture). On the other hand, germline mutations are those inheritable from parents, and hence are hereditary mutations.

There are dozens of conditions that arise from germline mutations in various genes, which can predispose individuals to develop different cancers, and hence it is important to identify them for risk estimation and prevention of cancers. These predisposition risks can be uncovered via various forms of diagnostic or screening procedures.

The tools presently employed include next generation sequencing, whole genome sequencing or targeted gene panels analysis, single gene testing, microarray studies etc. They are performed with pre and post testing genetic counselling, whence the purpose, means, limitations and measures for disease surveillance and prevenation are detailed with the patients, and individuals’ concerns are addressed. In this presentation, examples are shown to illustrate the above issues.

DNA mismatch repair (MMR) is an essential DNA repair process that is found to be deficient in some cancers. MMR deficiency is responsible for Lynch syndrome, a hereditary cancer condition. It has also emerged to be an important biomarker for immunotherapy.

As such, identifying patients with MMR deficiency from somatic panel testing is of significant interest. In this presentation, the identification of a case of germline MMR deficiency in a patient with advanced pancreatic cancer is discussed, highlighting genomic findings from somatic panels that can be used to facilitate the diagnosis.