Table 3.

Selected rare syndromes with increased risk of breast and/or ovarian cancer

Disease	Clinical features	Gene mutation/Inheritance	References
Li-Fraumeni syndrome	breast cancers, sarcomas, brain tumours, leukaemia, renal gland cancer	p53, high penetrance, AD	17, 33
Cowden disease	multifocal mucoid skin abnormalities, benign proliferative abnormalities of different organs, thyroid cancers, breast/ovarian cancers	PTEN, AD	34, 35
HNPCC	colon cancers, endometrial cancers, other organ cancers including breast and ovary	MSH2, MLH1, AD	36
Peutz-Jeghers syndrome	hyperpigmentation of the mouth, bowel polyps, colorectal cancers, small bowel cancers, gonadal tumours, breast cancers	STK11, AD	37
Ruvalcaba-Myhre-Smith (Z. Bannayan-Riley-Ruvalcaba) syndrome	macrocephaly, bowel polyps, "café-au-lait" on penis, lymphomas, thyroid cancers, breast cancers	PTEN, AD	38
Heterozygotic carrier status of "ataxia telangiectasia" gene	ocular ataxia, ataxia of cerebellum and skin, hypersensitivity to radiation, different site neoplasm including breast/ovarian cancer	ATM	39
ATH gene carriers	increased breast cancer risk	low penetrance 20-40%, AD	6
Klinefelter syndrome	gynaecomastia, cryptorchidism, extragonadal germ cell tumours, male breast cancer	47, XXY, low penetrance, <10%	40
Androgen receptor gene mutation	familial male breast cancer	androgen receptor	41
Constitutional translocation t(11q;22q)	increased breast cancer risk	balanced translocation t(11q;22q)	42

Inheritance

AD - autosomal dominant, AR - autosomal recessive