Will we soon be using prenatal genetic testing to pick and choose traits we want in our children? Are ‘designer babies’ around the corner? Are we on the verge of creating a demigod race by selecting and grooming for traits from the womb? To understand why people should not really be worried about this sci-fi scenario, let us start by reviewing a study conducted a few years ago to gauge consumers’ perception to prenatal genetic testing.
The research – consumers’ opinion towards prenatal genetic testing for diseases
To determine consumers’ opinion towards prenatal genetic testing for diseases and enhancements, researchers at NYU Langone Medical Center conducted a study in 2006-2007. 2,246 people who came to the NYU Human Genetics Program for prenatal genetic counselling were asked to participate in a survey. Almost half of them agreed to answer a questionnaire to indicate traits and conditions for which they would choose reproductive genetic testing.
The results were published in an article, “Consumers’ Desire towards Current and Prospective Reproductive Genetic Testing” published in the Journal of Genetic Counselling in April, 2009.
The results showed that a majority of people questioned would elect to have prenatal genetic testing for mental retardation (75%), deafness (54%), blindness (56%), heart disease (52%), and cancer (51%). Almost half agreed that they would choose genetic testing for a health condition that could result in death by 5 years of age, with the number of people desiring to learn of a condition that could result in death at 40 years of age dropping sharply to 25%.
The interesting part of the research results…
Most people did not desire genetic testing for enhancements, improvements or specific physical characteristics – with a minority wanting genetic testing for superior traits such as athletic ability (10 %) or superior intelligence (12.6%).
Commented Hathaway, the first author of the publication “Although the media portrays a desire for ‘designer babies,’ this does not appear to be true among consumers of genetic testing services”
The press responded to the results with a collective sigh of relief – ‘Genetic Testing Yes, ‘Designer Babies’ No’ wrote Michael Smith in Medpage Today.
The debate appears to have been rekindled this year with the birth of baby Conner in May 2013. Conner Levy is the first child to be born from an embryo screened with next-generation DNA sequencing to make sure that a fertilized egg with the right number of chromosomes was implanted in the uterus.
Baby Conners parents had turned to In Vitro Fertilization (IVF) to help them have a baby. Since it was first introduced in 1970, IVF has been a last resort for couples who fail to conceive but IVF success rate for women aged 35-37 is around 35%. One reason for this low rate of success is that many IVF embryos, which are produced by mixing sperms and surgically removed ova in the laboratory, have chromosomal abnormalities, higher or lower number of chromosomes, sometimes lethal genetic abnormalities which prevents them from implanting in the uterus or developing to term.
How next-generation sequencing can help IVF
The problem is – the embryos look healthy under a microscope. The only way to ascertain that the embryos have the right complement of chromosome would be to sequence the DNA. Baby Conner’s parents agreed to join a clinical trial for next-generation sequencing where researchers would safely remove a single cell from each embryo and use next generation sequencing to determine the number of chromosomes, but not to analyse specific genes. Baby Conner’s parents were not trying to select for improvements, augmentations, specific eye or hair colour – just a healthy baby.
Nevertheless, articles in the popular press wonder if, before long, parents will start asking the labs for more information about the genetic possibilities of each embryo. Is it just a matter of time before parents start looking for taller, healthier, better looking babies with mental smarts and physical attributes?
What’s the future for reproductive genetic testing?
It is true that the next logical step would be to reveal predisposition to disease encoded in the embryo DNA. However, getting to choose the eye color of an IVF baby still seems rather far-fetched, if not downright unimportant, inconsequential – also, eye-color is not a trait influenced by a single gene, rather by the interaction of many (about 10) genes. Similarly, traits like height & intelligence are unquestionably influenced by multiple genes. By the last count – 54 genes were known to influence height variations. As for intelligence, although data suggests it is heritable, I do not believe researchers have flagged the genes that collectively result in a person’s IQ. How could would-be-parents influence or choose for traits that are categorically influenced by several (known and unknown) genes?
Dr. Dagan Wells, the medical researcher at Oxford University who pioneered the cheaper next-generation DNA sequencing method used to identify the healthy embryo, summed it up accurately when he said…” IVF is still expensive and uncomfortable with no guarantee of a baby at the end. I can’t imagine many people wanting to go through the strains of IVF for something trivial”
(Source: The Guardian – ‘Designer babies’: the ultimate privileged elite?)
If you would like to learn more about IVF, fertility, and genetic testing, continue reading this related blog post: “Three-Person IVF Can Reduce Risk Of Mitochondrial Diseases”.