question about BRCA testing

BethL

question about BRCA testing

BethL

I had genetic testing last year and tested negative for BRCA 1 & 2.  A friend of mine has had two of her aunts (her mother's sisters) diagnosed with bc before the age of 45.  Her mother has been followed closely, so far so good.  My friend is 31 and wondering if she should be concerned. 

My question is this.  If her mother tests negative for BRCA, then does that automatically mean that my friend is negative.  Assuming that there is no mutation on her fathers side.  Should they both get tested, or have her mother tested and if negative stop there? 

Thanks.

yellowrose

I was told by my genetics counselor that if I tested negative, that my children could NOT get the defective BRCA gene from my side of the family. 

Your friend's mother might want to talk to her husband's family, if possible, to investigate cancer patterns on his side.  That way when she meets with the counselor, she can discuss her concerns about her children's medical heritage from both sides of the family.

lvtwoqlt

After my mom was dx with BC she had the genetic testing done, her sister dx with ovarian at age 36 put her in the high risk group. She was told the same thing that txgrl said about if she was negative, her children would not get the gene from her. If she was positive, the next step would be to test the children (if requested) to see if they had the gene. She tested negative. I did not have the test done but last yr was dx with DCIS, so not having the gene does not necessarily prevent one from not getting BC. It is only a tool used to try and predict your specific odds of developing BC.

Sheila

DianeE

I had the BRCA testing done and was negative.  I was told by genetics counselor that my daughter did not need to be tested since I was negative.  Hope that helps.

Diane

otter

The pattern of inheritance of breast cancer susceptibility with BRCA mutations is "autosomal dominant." That means it is not necessary to inherit defective BRCA genes from both parents--all it takes is one parent to transmit the bad gene.

Also, as txgrl01 said, a defective BRCA gene can be inherited from either side of the family (mother or father).  That's what the "autosomal" means--the pattern is not linked to the "X" chromosome.  So, it isn't enough to test just the mother; even if she does not have a BRCA mutation, it could be passed on via the father's genes.

Here is some very good information about BRCA testing, from Sloan-Kettering Cancer Center in New York: 

http://www.mskcc.org/mskcc/html/8623.cfm

Here's another web page, from Stanford University, that explains the inheritance patterns and the factors that help determine whether someone with a BRCA mutation actually develops cancer:

http://cancer.stanford.edu/information/geneticsAndCancer/types/herbocs/

I hope that helps!

otter 

vbeck

OK, so if her mother was tested and it came back negative, then she cannot get the gene from her mother (good news ).