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BRCA1

From SNPedia
is agene
is mentioned by
Full namebreast cancer 1, early onset
EntrezGene672
PheGenI672
VariationViewer672
ClinVarBRCA1
GeneCardsBRCA1
dbSNP672
DiseasesBRCA1
SADR672
HugeNav672
wikipediaBRCA1
googleBRCA1
gopubmedBRCA1
EVSBRCA1
HEFalMpBRCA1
MyGene2BRCA1
23andMeBRCA1
UniProtP38398
EnsemblENSG00000012048
OMIM113705
# SNPs2606
 Max MagnitudeChromosome positionSummary
i400037741,276,045
i400037841,209,079
i4000453
i4000456
i4000457
i4000459
i400046141,245,992
i4000464
i4000465
i500557141,243,941
i5005573
i5009490
i5009493
i5009499
i5009509
i5009511
i5009520
i5009526
i5009536
i5009541
i5009542
i5009546
i5009552
i5009553
i5009555
i5009558
i5009559
i5009586
i5009589
i5009591
i5009592
i5009593
i5009595
i5009596
i5009597
i5009599
i5009603
i5009604
i5009605
i5009607
i5009613
i5009614
i5009615
i5009619
i5009621
i5009623
i5009624
i5009626
i5009629
i5009630
... further results


BRCA1 is a human tumor suppressor gene. Like most genes, variations in the BRCA1 gene can be either causal for a given disease, or associated with somewhat higher risk, or benign.

However, "causal" does not mean that there is a 100% certainty that a person with such a variant will develop the disease. For individuals with causal BRCA1 variations, a good clinical summary provided by OMIM states the disease odds as[1]:

  • Mutation carriers have an increased risk of developing breast and/or ovarian cancer at an earlier age
  • Lifetime risk of breast cancer in mutation carriers is 80 to 90%
  • Lifetime risk of ovarian cancer in mutation carriers is 40 to 50%
  • Increased risk of bilateral breast cancer


Similarly, a 2017 publication involving ~10,000 women over 20 years concluded that women with BRCA1 mutations have on average a 72% risk of developing breast cancer by the age of 80, and an average lifetime risk of ovarian cancer of 44%.[PMID 28632866]

There are over 500 BRCA1 variants that are considered causal, but almost all are very rare. It is estimated that all causal BRCA mutations combined occur in less than 1/3rd of 1% of people. Some of "slightly less rare" causal BRCA1 SNPs include:


Other causal BRCA1 mutations include:

  • rs28897696, known as A1708E, predicted to be highly linked & causative
  • rs55770810, known as R1699W, predicted to be linked & causative


Many other variations of varying consequence are known. These include:


This report from the NCI advises:

  • The cost for genetic testing can range from several hundred to several thousand dollars.
  • because the results of genetic tests can affect a person's health insurance coverage, some individuals may not want to use their insurance to pay for testing
  • it can take several weeks or months for test results to become available


See also BRCA1 and BRCA2 for an extensive list of breast cancer related SNPs (including variations of all types from benign to causal).