My Mother, My Cells

What I learned when I couldn't wait to explore my genome.

March/April 2011

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My Mother, My Cells

Carl Wiens

My mother was diagnosed with breast cancer the summer before I entered the second grade, when she was 39. I remember vividly the time she picked me up at school wearing her newly acquired short, blonde wig—its contrast to the beautiful brunette locks her scalp had shed. I spent years trying to forget the visual of nasal oxygen tubes and her colorless face when we visited the hospital.

She received what I would later learn to aseptically call a single mastectomy and was lucky enough to have life mostly return to normal. Other than times like my own annual exams, I had mostly forgotten about this turn of events for almost 18 years.

Then, last summer, I heard about GENE210, the personalized genomics class led by medical student and doctoral candidate Keyan Salari and genetics professor Stuart Kim. The course would expose medical and graduate students to the interpretation of genetic studies. And it would give students a subsidized opportunity to obtain their personal genotype data. As a PhD student in immunology, I jumped at this chance to learn so much of what was until recently unknowable.

My parents—like many scientific lay-persons—didn't necessarily share my fervor: They asked if I really wanted to find out how I was going to die. But I knew that wasn't quite what I'd learn, and I ignored their concern, responding, "Knowledge is power!"

The particular knowledge I'd gain would come from "recreational genotyping," a service offered over the counter by companies like 23andMe. Using a DNA sample—cheek cells in a bit of my saliva—the company performs a test that returns some insight into one's genome: risk factors for numerous diseases and carrier status, information about ancestry, some predictive information about traits like baldness or drug sensitivities. Findings give a glimpse, too, into the potential power of full-genome sequencing, which likely will lead to personalized medicine in the future.

My information regarding mitochrondrial DNA (which we inherit only from our mothers) confirmed that I am of Ashkenazi Jewish lineage. Modern genetics testing has revealed the amazing fact that 50 percent of the Ashkenazi Jewish population are descended from just four founding mothers who moved to Europe from the Middle East in the 11th century.

Among the resources offered for GENE210 was the documentary In the Family. The film's director, Joanna Rudnick, an Ashkenazi Jewish woman, learned in her late 20s that she carried a mutation in a gene that increases the risk of breast cancer, specifically in the Ashkenazi Jewish population. As I watched In the Family, I could no longer ignore a blaring question.

Many years ago, my mother had refused to be tested for the three common Ashkenazi Jewish mutations in the breast cancer genes (BRCA 1 and 2) and the more advanced option of full gene sequencing. She will neither confirm nor deny any fears that she is still vulnerable to cancer in her remaining breast or to ovarian cancer, which is associated with the same genetic mutations. Her gynecologist has tried, to no avail, to persuade her to be tested so that I might know if I have a definite genetic risk. Knowing my mother, there was no chance she'd change her mind, even after 18 years of remission.

I also knew that the way the data was collected was specifically targeted for the three Ashkenazi Jewish mutations (and not all the endless possibilities of mutations that might exist). Only if I were to have one of the three mutations would I get a positive result. In short, this means this particular information has a very high rate of false negatives.

So I began to think what I would do with the information. If the data came up positive, would I tell everyone I would likely develop breast cancer? Would I rush to get married and have children so that I then could get my breasts and ovaries removed as filmmaker Rudnick implied that she would do?

Conversely, if my result came up negative, what would change? Nothing. My risk would still be elevated because my mother had been diagnosed so early in her life. It wasn't as if I would be relieved of the burden in any way.

Did I really want the stress of knowing when, in my current situation, I wouldn't change anything? After much discussion with family members and friends, I opted out of learning my personal breast cancer data. Having previously been so passionate about personalized genomics, I felt like I'd let myself down. As soon as I could have let knowledge be power, I faltered.

My solace is that, at any time in the future, I can unseal my data. I hope that one day, when I feel more able to act on the information that I obtain, or when preventative measures may not be so invasive, I will welcome the data with open arms.

MAYA BENBARAK plans to learn to knit before any son of hers likely goes bald.

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