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Monday, 14 March 2011

The power and influence of newborn genetic testing

I remember my newborn son’s heel prick test as an emotional blur. His screams added to the din of the tightly packed ward as the doctor struggled to extract sufficient blood. He must have wondered what sort of world he had been born into.

The short term discomfort was in his best interests as the heel prick test saves lives. Many metabolic diseases can be managed by diet and lifestyle changes but are fatal if left undetected. The benefits seem clear cut – disruption to a single gene cause quantifiable alterations in metabolism which can be corrected by environmental modifications.

A paper in January 2011 issue of Medical Anthropology makes it all appear a little more messy.

The study followed 60 newborns diagnosed with metabolic diseases in a Californian paediatric genetics clinic. The authors observed interactions between the families and geneticists and documented the emotional world of parents.

The main thrust of the paper is loss of the dream of a perfect baby after a positive screening result. Here I will focus on what struck me most about the findings: the power and influence of genetic knowledge on those whose lives it touches.

Many of the observed diagnoses in the study were ambiguous, combinations of mutations whose significance weren’t fully understood. The children appeared healthy but the parents were forever fearful of disease emergence and its serious consequences.

The research captured how parents responded and the indirect effect on their babies’ early childhood experiences.  The following quotes are from parents whose children were diagnosed with MCADD, a disease of fat metabolism in which sufferers cannot metabolise fat when blood sugar levels drop.
The mother of a 2-year-old boy with MCADD described her son as a ‘‘special case’’ because only one mutation was identified through DNA testing, yet his metabolite levels were high enough to warrant close clinical monitoring. Although the laboratory’s failure to detect a second mutation left unresolved questions about whether the child actually had MCADD, as opposed to being a carrier, the boy’s father refused to leave the child alone with anyone other than his wife.
Maria, the mother of a 6-month-old boy with MCADD, noted that her son seemed as normal as her two older children, yet that she worried ‘‘all the time’’: when he slept 6 hours ratherthan 3 or 4, or when she gave him vegetables—even though the dietician said this was okay. An ear infection at 4 months of age provoked grave fears about metabolic crisis, while online research made Maria concerned about the possibility that routine immunizations could lead to metabolic problems in children with MCADD. She told us that she worries constantly that she will do something wrong.
Dan, father to Molly who has MCADD suggested she was ‘‘progressing maybe at an 80 percent level compared to other kids’’ on motor development and Kim [mother] recognized that Molly was ‘‘not as verbal as maybe someone else her age.’’ But because Kim had ‘‘taken her to sign language since she was about like seven or eight months old,’’ she exceeded other children in her ability to communicate her needs. Thus, Kim concluded, ‘‘We want her to speak more. But, I mean, other than that, she seems just like an average normal kid, I mean, we think.’’
I would not argue that parental conflict should lead to questioning the value of the test itself, and the authors do not pass judgement either way. The children have a fatal disease and knowledge is lifesaving. However, it is clear that genetic data have power and reach far beyond the disease information they pertain to.

Much potential damage can be abated by a deep comprehension of the subtleties of the test results. Genetics and disease are untidy and will get more so as further layers of knowledge are acquired. The communication challenges are great - the science is tangled and forever shifting, moral sensibilities are individual and subjective, and the implications of getting it wrong cut deep.

The key is to transmit a nuanced understanding of the complexity to parents – the unknowns, the range of possible outcomes, how mutations influence the child and what is normal developmental variation, how childhoods can be overshadowed by understandable parental fear.

Future discoveries mean the lines between established illness and normal human variation will be continually redrawn. This research shows that we should consider not only false positives and negatives but also the psychological burden on the families who are told they are genetically ill.

Before we reach the stage of obligatory newborn genome sequencing we need a wider acknowledgement of the power of the data at the level of the individual family. The depth of understanding of the parents, and later of the child, could arguably have more of an influence on the life of the child than any genetic mutations.

ResearchBlogging.org

Buchbinder, M., & Timmermans, S. (2011). Medical Technologies and the Dream of the Perfect Newborn Medical Anthropology, 30 (1), 56-80 DOI: 10.1080/01459740.2010.531065

4 comments:

  1. I came across your post as the father of a 2.5 week old girl, who was diagnosed with MCADD by the heel-prick test. I can relate to some of the emotions mentioned here, even after a couple of weeks.

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  2. Hi, thanks for your nice post on DNA test. I really liked it. I'll come again and hope to find more information on metabolic dna testing.

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  3. Thanks for this article Elaine. I agree that one needs to consider the potential psychological burden that can follow these test. However, it's better to know than not know, I think. Thanks for the good post and keep up the work.

    Btw, I found this article after I ordered a dna home testing kit from <a href="http://www.genetictestkits.co.uk/>genetictestkits.co.uk</a> - a great site for all things about DNA and home testing kits.

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  4. I think the link should be genetictestkits.co.uk

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