There’s a need, a mechanism in place for screening, and commercial enterprises dedicated to clinical integration. Read on to find out why prenatal testing is leading the pack in genomic medicine, and all about one of its leading lights.

When it comes to prenatal genomics, there aren’t many bigger names than Diana Bianchi. Whether she’s seeing patients, researching, presenting, writing, editing, or even acting, she is doing a tremendous amount to push the field forward. Considering that the prenatal field is leading the way in genomic medicine, that makes her a crucial figure in the wider field of genomics. Ahead of her second headline turn at the Festival of Genomics, we found out where it all began.

Diana Bianchi headshot

Photo: Leonard Greco

FLG: You’re speaking at the Festival of Genomics again this summer on prenatal testing in the genomic era. Last year you made a compelling argument for why prenatal testing is probably one of the best developed areas of genomic medicine today. Why is it so far ahead of some of those other areas?

DB: First of all, the condition that is being tested, pregnancy, is extremely common. So it differs from, say, cancer or a rare inborn error of metabolism. There are statistics that indicate that roughly 90% of women become pregnant at some time in their life and half of the population is female. Offering testing for autosomal aneuploidy, most commonly Down syndrome, is a recommended part of prenatal care in most developed countries. Thus, there is already a mechanism in place for screening. The genomic testing is more accurate than the current standards of care and industry has pioneered and disseminated the screening. So you have a need for testing, a test that works well, and multiple commercial enterprises dedicated to getting the testing integrated into clinical care. I think all of those components have combined to make prenatal the most widely used application in genomic medicine.

FLG: You published an article in Nature last summer ‘Pregnancy: Prepare for unexpected prenatal test results.’ From my perspective, I think it raised two really interesting points. The first was highlighting that tests could return some really interesting information outside of what they might specifically be designed to look for. And secondly, the rate at which technology and our understanding is developing, means that what we ask patients to consent to is potentially much more open ended these days. How do you go about investigating those varying applications while making sure that patients are fully informed along the way?

DB: Here’s an area where the technology has somewhat outpaced the practical applications and the entire consent process. Pregnancy is unusual in the aspect that when you do DNA sequencing on a blood sample, you’re simultaneously sequencing two individuals, the mother and the foetus. There’s no other situation where that occurs, except maybe with twins. When pregnant women agree to have the test they are not necessarily informed that the testing will potentially detect something about themselves. I think it’s important to emphasise that it’s still a problem that not all women are actually signing consent forms for this type of testing, and not all of the consent forms mention the possibility of incidental findings about the mother. So there’s this unique situation where consent is being provided but it’s being focused mainly on the foetus. It’s an opportunity to investigate the boundaries of the testing. Last year, I talked a little bit about the possibility of using the false positive results as an opportunity to figure out that the mother actually has a small tumour that’s releasing DNA into the circulation and creating a genome-wide imbalance type of result that unfortunately gets misrepresented as aneuploidy in the foetus when it’s actually aneuploidy in the mother due to a tumour.

 

Read on to hear Diana Bianchi’s take on making sure consent forms do get signed, what’s to come in the next 12 months for prenatal, and who she’ll be portraying at the next live play ‘DNA Dialogues, Dilemmas and Drama at the Festival of Genomics Boston in June 2016. Turn to page 29.

 

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