Constitutional genetic exome analysis will be performed on the blood sample. If necessary, an analysis on a second independent sample (jugal smear) will be carried out if a probably pathogenic or pathogenic variant in a hereditary cancer predisposition gene is identified.

For each patient included:

• A family tree is drawn up, reporting personal and family histories of cancer. The patient's anatomopathological reports, related to his or her tumor lesions, are retrieved, in order to confirm/clarify individual or family diagnoses.
• A blood sample and a jugal smear are taken to enable constitutional genetic exome analysis for research purposes.

Variants of interest are selected from the data using the following filter:

• Variant with frequency < 1% (GnomAD)
• Shared by at least 2 sufferers in the cohort
• Truncating (nonsense, with frame shift, on a canonical splice site -2, -1 and +1 +2)
• Missense from a list of "cancer" genes and Combined Annotation Dependent Depletion (CADD) score > 20 (COSMIC Tier1 and Tier2)

Variants will be interpreted using various databases and prediction tools:

• Functions: genecards, pubmed, uniprot
• Expression profiles: cbioportal, GEPIA
• For splice variants: CADD, Splice AI
• For exonic variants: CADD, SIFT, Polyphene

Number of patients with a mutation on BRCA1, BRCA2, CHEK2, PALB2, POT1, MSH6 or MLH1