Download BRCA1

Investigating the BRCA1
Mutation
F.R.E.S.H Docs
Angelina Jolie
Actress, Film director, and Screenwriter
Mother had Breast Cancer and died at 56
from Ovarian Cancer
Jolie decided to undergo a doublemastectomy in order to reduce her risk of
developing cancer
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What Are The Specific Objectives For
Our Group Study?
 To establish what the BRCA1 mutation is.
 To learn the cellular function of BRCA1.
 To thoroughly investigate how disturbance of
these functions ultimately leads to cancer.
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Cell Functioning without BRCA1
mutation
 The gene that the BRCA1 is located on, codes for a protein that
repairs DNA.
 The DNA can be damaged during replication or from exposure to
carcinogens.
 When the DNA breaks, the cell cannot pass on damaged genetic
material, so it will self destruct through apoptosis.
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What is the BRCA1 mutation?
 BRCA1 mutation is a
change made to a gene
which normally codes for
a protein that functions to
repair damaged DNA.

 This gene is located on
the 17th chromosome.
 There are two noted mutations in the
BRCA1 gene that lead to 80% to 90% of
the cancers developed from mutations
within this gene’s sequence.
 These mutations specifically result from
the addition or subtraction of one or
more nucleotides from this sequence.
How does the mutations lead to
cancer?
 When DNA is damaged, multiple proteins within the cell work
to recognize the damage and correct it
 The BRCA1 mutation may code for a protein that no longer
correctly repairs the DNA
 The cell then may replicate the mutated DNA, which leads to a
higher rate of mutation
 This generates a greater chance that the specific mutations, which
cause cells to divide uncontrollably, will develop.
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What are the odds of developing
cancer with this mutation?
 The BRCA1 mutation gives women a 60% to 80% chance of
developing Breast Cancer, and 20% to 45% chance of
developing Ovarian Cancer.
 Women without the BRCA1 mutation have a 13% chance of
developing Breast Cancer in their lifetime.
 Men possessing BRCA1 mutation have a 1% to 5% chance of
developing Breast Cancer.
Men may be at such less of a risk because they do not
have the high levels of the hormone estrogen.
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Does the BRCA1 mutation
inheritance skip generations?
 No, the gene does not skip generations.
 Children of a parent with the mutation
have 50% chance of inheriting the
mutation.
 The mutation is genetically inherited
dominant, yet its phenotypic interaction
within the cell might not actually lead to
its expression.
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 Carrying this mutation does not
guarantee that cancer will develop, it just
makes the chances that it will develop
very high.
Conclusion
 Having a mutated BRCA1 gene does not guarantee that cancer
will develop; it leads to a higher rate of mutation
 In order for cancer to develop there are a number of specific
mutations to the cells DNA that need to occur and even with the
BRCA1 mutation, it is rare that these will all unfold within a single
cell
 Yet, there are billions of cells in the breast and ovarian tissues
resulting in a greater chance that cancer will develop
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Additional Questions
 Are there preventative measures being explored specifically
dealing with the manipulation of genetic sequencing?
 If someone discovers that they have the BRCA1 mutation, how
does it affect their life from that point?
 Is testing for this BRCA1 mutation offered at any age?
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Sources
http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA
http://journals.cambridge.org/fulltext_content/ERM/ERM3_14/S146239940100309Xsup004.htm
http://ghr.nlm.nih.gov/gene/BRCA1
http://inthefamily.kartemquin.com/content/brca-101
http://breakthroughs.cityofhope.org/latinas-breast-cancer-genetics/2991/
http://www.cancer.gov/cancertopics/understandingcancer/targetedtherapies/breastcancer_htmlcourse/p
age5
http://en.wikipedia.org/wiki/File:Autodominant_en.svg
http://leeasbell.wordpress.com/2012/05/29/brca1-and-brca2-risk-stats-simplified/
https://www.23andme.com/health/BRCA-Cancer/