Weaving together the DNA of parenthood

31 October 2012 by Nathalia Holt, posted in Uncategorized

In 2007, Anne Morriss and her partner brought their newborn son home from the hospital. They were brand new parents, filled with both fear and delight at the tiny little person they held in their arms. At the hospital, their new son had received a blood test, commonly given these days to detect genetic disorders. Their son had been home only a few days when they received the phone call that all parents dread. After a quick introduction, the doctor on the other end bluntly asked “Is your child still alive?” Anne, becoming fearful, replied yes to the startling question. The doctor on the other end responded, “Can you go check and come back to the phone?”

Anne Morriss and her son

Anne describes this terrifying moment as a “fall through the looking glass.” Anne was a new mom, filled with hormones and fear.  She and her partner learned that their child had MCADD. MCADD is an autosomal recessive genetic disease; so two copies of the gene must be defective in order for the disease to show up. This means that we can be unknowing carriers: holding a defective copy that may pose a problem if the person we want to have a baby with is also a carrier. The vast majority of cases, 90%, are from a single point mutation, one nucleic acid out of billions that was copied incorrectly.

MCADD, or medium chain acyl-CoA dehydrogenase deficiency, is a rare condition that occurs when the enzyme we need to break down fats doesn’t work properly. When the body can’t break down fat, it can’t convert it into energy. This means that all the body has left is glucose. There’s a finite amount of glucose available and we burn through it quickly. When it’s gone, those with MCADD have nothing left. This is why MCADD is so dangerous. After the first attack, 25% of children with the disease die. Before genetic screening, these deaths were often misdiagnosed as either Reye’s syndrome or SIDS. This remains a problem today; there are still MCADD deaths masked under other names.

As Anne rushed to bring her 5-day-old son back to the hospital to receive critical treatment, she could have little idea of the struggles the next few years would bring. Suddenly, her world would revolve around feeding her son. If he didn’t receive regular meals, he could potentially die. For the first year, Anne would have to feed her son every three hours.  It’s a scenario that most sleep deprived parents can’t even imagine. Anne breast-fed her son, which can be difficult under the very best of circumstances. As she kept to the strict schedule, she was essentially feeding non-stop. As they moved into the toddler years, new challenges emerged. They had to deal with a child beginning to assert his independence, especially at mealtime. Anne remembers a lot of peanut butter and jelly sandwiches and laughs when she recalls the puzzling looks of friends when they saw jars of baby food, given to a three year old who should be well past the blended food stage. In between all of these struggles were countless hospital visits, punctuated by frightening illnesses and vomiting.

Anne conceived her child through an anonymous donation from a sperm bank. She couldn’t know that within her own DNA, the genetic code she would pass down to her child, was one defect copy of the gene that encodes the needed MCAD enzyme. Because it’s a recessive trait, Anne’s one intact allele provided her with all the enzyme she needed to break down fat. By itself, Anne’s compromised MCAD allele did not have pose a risk. However, when combined with the DNA of her sperm donor, the danger increased. The sperm donor’s DNA also lacked a functional copy of the MCAD enzyme. When the genetic material melded to make a child, it was a roll of the dice. There was a 25% chance, a chance Anne wishes she had known, that her child would be born with two defective copies of a gene, incapable of making the MCAD enzyme.

Without any formal training in science, Anne received a crash course in genetics. She devoured any information she could find. Online she found a support group founded by Deb and Dan Gould, a couple who lost their 21-month-old daughter to MCADD in 1985. She found both knowledge and comfort in the experiences of other families with the disease. She looked at science in a way common to those whose children suffer from disease; science became a way for her to gain control. She couldn’t help but feel “surprised that with all our technology we couldn’t prevent my child from having the disease.” The more she learned the more convinced she became that the real problem was “human barriers” and not scientific ones.

The FDA has struggled with the right of individuals to access their own genetic information. As the price of genetic sequencing dropped, the inevitable happened:  multiple companies cropped up providing DTC (direct-to-consumer) genetic testing. In exchange for a few hundred dollars and some saliva, these companies can give a consumer their genetic data, served on a platter.  The FDA has given mixed messages to these companies, sending warning letters that the services they offer may require FDA review. The regulatory agency has found itself torn between wanting to ensure that medical information is routed from physicians, and wanting to preserve the individual rights of patients. Genetic testing companies have, for their part, argued that they are offering information, not a clinical test. This, they say, means they can operate without FDA approval.

One exception to this is the company 23andme, arguably the most popular personal genetics company. This past summer, 23andme applied for FDA approval. We don’t yet know the outcome of this ongoing conversation with the federal government.  Americans, it seems, are as split as the FDA is on this issue. A study done by Forbes indicates that 50% of Americans believe we should have access to our genetic code. Many scientists, however, feel differently. Two scientific societies in Europe have come out against this access. There has also been backlash against DTC genetic testing from some prominent scientists in the US (see here and here for a few examples). Chief among these arguments is that we don’t fully understand the connections between gene and disease. To diagnose individual risk may open up a person to unnecessary interventions, some of which are inherently precarious. Others worry that information gleaned from these companies could be used for nefarious purposes in the future: aborting babies based on gender, denying opportunities to those with certain disease risk, etc.

As Anne and her partner decided to conceive their next child they took precautions. They screened potential sperm donors for MCADD risk. They could not, of course, screen against other genetic diseases that Anne might, or might not, be a carrier for. They were lucky enough to have a healthy child, a baby who is now a year old. But Anne, who holds an MBA from Harvard Business School, is an entrepreneur, and an author, dreamed of a world where every couple could know the disease risk of their potential child.

Born from her experiences and fed by her desire to protect other parents, she co-founded Genepeeks in 2010 with molecular biologist Dr. Lee Silver. Genepeeks differs from other DTC genetic companies in one critical way: the company aims to analyze the disease risk in potential children. That is, before they are even conceived. This takes away many of the ethical concerns that have been raised for other companies. It also makes the company relatively exempt from FDA prying. It does not, however, exempt them from criticism. This was evident in the response of Dr. Lawrence Brody from the National Human Genome Research Institute and Dr. Mildred Cho from the Stanford University School of Medicine, who, when quoted recently for Science, were critical of the ability of science to predictably model disease risk. It’s normal for us as scientists to worry about our limited understanding of genetics and the way this understanding may be misinterpreted. Yet, we have to remember that there are real people who can benefit from this technology. There’s a woman out there visiting a sperm bank who could use our unquestionable ability to predict the risk of MCADD in her potential child. As Anne herself says, “we are all carriers of something…we just don’t know what it is yet.”

Genepeeks will begin testing their company model at a single sperm bank. Anne is hopeful that one day it might be able to help parents worldwide protect their future children. Despite the challenges they have gone through as a family, Anne says that the “truth is we are so lucky.” Walking into Boston Children’s Hospital, she has the “healthiest kid in the building.” She knows that it could be much, much worse. She enters this controversial arena with the best intentions; she wants to save other parents from heartbreak.

This Halloween, Anne’s son will go trick-or-treating. It’s a “tough day” says Anne as she describes the difficulty of keeping a five year old boy who can’t break down fat from eating too much candy. Anne’s son is planning on dressing as ‘superboy,’ his sibling as ‘superbaby’ and Anne herself as ‘supermama.’ It’s a fitting title for an amazing woman and mother.

 

Learn more about Genepeeks here

Follow Anne on twitter @annemorriss

Find Anne’s book here

 


4 Responses to “Weaving together the DNA of parenthood”

  1. Kausik Datta Reply | Permalink

    Well-written, and a great story. From a scientist's perspective, I can understand the hesitation against direct-to-consumer genetic testing; simply put, once the consumer has that information, then what? Is an individual consumer going to be bound by the same ethical obligations and biomedical concerns as are foremost in a scientist and/or physician's mind when dealing with genetic data? But I agree that there needs to be in-depth and intense discussions about this, in a dispassionate manner, particularly since the technology is already around and its misuse/unethical use is difficult to prevent.

    For that last statement, let me provide an example. Prenatal diagnostic testing (including genetic testing and ultrasonography) is severely restricted/regulated in India. Even if genetic testing is done based on family history or other clinical concerns to check for abnormalities, the doctors are prohibited by law from revealing the fetus's biological sex. This was considered necessary to prevent an extremely unfortunate practice in vogue in India, sex-selective abortion of female fetuses. Although the enforcement of the related laws has reduced female feticide (leading to a 16-21 point increase in child sex ratio, according to a 2011 study), the misuse of the technology - with deplorable consequences - carries on till this day. It seems to me that problems of this type cannot be solved ever solely by regulating technology, but by involving people, common people whose lives are impacted by the said technology.

    Waiting to read MOAR from you! :D

  2. Nathalia Holt Reply | Permalink

    I agree there is much potential for abuse here. Many of the markers we have for say, autism, are preliminary. What about controversial markers we find in the future? Is it fair to make parents worry about potential risk for a child that hasn't been conceived? At first glance, as a scientist myself, it seemed like a bad idea. There's so much nuance to interpreting this data, how can we heap it onto parents. But when you actually hear Anne's story it makes sense. Here are diseases that are completely preventable by our own technology. This field is only going to get more complicated, we have to start deciding at the governmental level how to regulate it.
    Thanks for reading and the great comment!

  3. Khalil A. Cassimally Reply | Permalink

    Thing is, at the end of the day, I don't believe that the discourse about whether direct-to-consumer genetic-testing actually matters. Because, it is going to happen whether we like it or not. The means to perform good genetic tests are available and affordable. Those are the only two real prerequisites for it to happen and grow more prominent.

  4. Nathalia Holt Reply | Permalink

    Totally agree Khalil, it is happening. You can buy the kit from 23andme today. But I do wonder how we as scientists can support this movement responsibly. We have to figure out which companies are responsible and which tests make sense and support those.

Leave a Reply


6 − = one