Connexion

GENATLAS PHENOTYPE

last update : 10/11/2006

Symbol	BRCA1
Location	17q21.31
Name	hereditary breast/ovarian cancer
Corresponding gene	BRCA1
related resource	Breastcancer
Other symbol(s)	BCCR5
Main clinical features	predisposition to breast cancer and ovarian cancer, as well as prostate cancer familial occurence, early onset, bilateral or multifocal tumors, male breast cancer are evocative of a cancer-predisposing mutation risk of prostate cancer
Genetic determination	autosomal dominant
Prevalence	cancer-predisposing BRCA1 mutation : between 1/500 and 1/1000.
Related entries	BRCA2, TSG17B, (OMIM : 114480)
Function/system disorder	endocrinology
	neoplasia
Type	susceptibility factor

Gene product

Name

breast cancer type 1 susceptibility protein

Mechanism(s)

Gene mutation	Chromosome rearrangement	Effect	Comments

various types		abnormal protein/loss of function	more than 300 different germline mutations, over 90p100 producing a premature stop codon and approximatively 60p100 unique to an individual family, with a significant proportion of large deletions and duplications resulting from Alu-mediated recombination

Remark(s)

multifactorial disorder caused by both non-genetic and genetic factors; founder mutations are observed in some ethnic groups.

Genotype/Phenotype correlations

the risk of developping cancer is variable within families with the same mutation

In high-risk families, women who test negative for the familial BRCA1/BRCA2 mutation have an increased risk of breast cancer consistent with genetic modifiers

In light of this, such women should still be considered for continued surveillance