Psychosocial and clinical factors of probands impacting intrafamilial disclosure and uptake of genetic testing among families with BRCA1/2 or MMR gene mutations. 
Intrafamilial disclosure of hereditary cancer predisposition in BRCA1/2 and mismatch repair gene (MMR) syndromes allows appropriate prevention strategies in at-risk relatives.  We previously showed in a nationwide study that the uptake of genetic targeted testing (GTT) in these families was only 30%.  We aimed to identify the clinical and psychosocial factors affecting the probands' intrafamilial disclosure and relatives' uptake of GTT in BRCA1/2 or MMR syndromes.  We assessed clinical variables, family history, and psychosocial variables of probands (depressive symptoms, anxiety, alexithymia, optimism, coping, family relationship, perception of cancer risks, and of hereditary transmission), together with disclosure and uptake of GTT within 103 French BRCA1/2 or MMR families.  Among relatives eligible for GTT, 68% were informed of the predisposition, and 37% underwent GTT, according to probands' reports.  Intrafamilial disclosure was inversely associated with the degree of kinship (P < .01).  In multivariable analysis, disclosure increased with time since probands' genetic diagnosis (P < .01) and probands' feeling of family cohesion (0.01).  GTT uptake increased with probands' depressive symptoms (0.02) and decreased with probands' perception of cancer risks (0.03).  BRCA1/2 and MMR groups did not differ concerning family information and GTT uptake.  This study identified factors affecting disclosure to relatives and GTT uptake in BRCA1/2 and MMR syndromes and gives new insights to improve probands' follow-up and intrafamilial sharing of genetic information.