Fetus' Complete Genome Mapped from Mom's Blood and Dad's Saliva
A sample of the mother's blood and saliva of the father is all that it takes to map out entire DNA sequence and identify almost 3,000 genetic disorders in the fetus, scientists say.
This new non-invasive method lowers risks of miscarriage associated with the standard forms of pre-natal genetic testing.
Scientists collected samples from an expectant mother at about 18 weeks into pregnancy and a sample of saliva from the father, mapped out the entire DNA of the fetus. They verified the results using sample from the umbilical cord blood that was collected at birth of the baby.
Their predictions were 98 percent accurate, reports Los Angeles Times. They were able to predict almost all genetic mutations in the baby.
"The capacity of genomics to generate data is outstripping our ability to interpret it in ways that are useful to physicians and patients. Although the non-invasive prediction of a fetal genome is now technically feasible, its interpretation – even for single-gene Mendelian disorders -- will remain an enormous challenge," said Shendure, associate professor of genome sciences at the University of Washington and senior author of the study.
"The improved resolution is like going from being able to see that two books are stuck together to being able to notice one word misspelled on a page," said Jacob Kitzman, lead researcher of the study.
The scientists are optimistic that this new method will help detect genetic disorders in a safe and efficient way.
"This work opens up the possibility that we will be able to scan the whole genome of the fetus for more than 3,000 single-gene disorders through a single, non-invasive test," said Shendure.
There are people who do not share the scientists' enthusiasm about the study like from Prolife camp who say that this would lead to an increase in abortion rates.
"One always hopes, vainly, that in utero testing will be for the benefit of the unborn child.
But, whilst this new test may not itself be invasive, given our past track record, it is difficult to imagine that this new test will not lead to more abortions," said Josephine Quintavalle, founder of the Pro-Life Alliance, reports The Telegraph.
Genetic testing has been the center of controversy for many years now. Experts (and commoners) feel that genetic testing is a threat to privacy.
Last year the Governor signed Senate Bill 559 (Padilla), a law that protects citizens from being discriminated on the basis of genetic testing. The citizens cannot be refused insurance cover, housing, education or employment based on genetic testing.
Then there are philosophical and ethical questions about genetic testing like who decides what is normal and what is not and the need of treatment.
Also, genetic testing and its effects on research is a widely debated topic. Recently Nature reported about the effects of a proposed California Genetic Information Act and its effects on research.
The present study is published in the journal Science Translational Medicine.