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DNA Test for Babies Pinpoints Mutations, Speeding Diagnosis 12..
Published: October 3, 2012 10 Comments
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Her doctors suspected a genetic disorder, and as it happened the hospital had just begun a study of a new technique for quickly
analyzing the DNA of newborns, zeroing in on mutations that can cause disease. This new method, published on Wednesday in the
magazine ScienceTranslational Medicine, is a proof of concept — a demonstration in four babies that it is possible to quickly scan a
baby’s entire DNA and pinpoint a disease-causing mutation in a couple of days instead of the more typical weeks or months. The study’s
investigators said the test could be one of the first practical fruits of the revolution in sequencing an individual’s entire DNA. For the
baby withseizures, her doctors provided a sample of her blood. The analysis took only 50 hours and provided an answer. The baby had a
mortal gene mutation so rare that it had only been reported once before.
- If only, said Dr. Joshua E. Petrikin, one of the baby’s doctors, the test could have been done within days of the baby’s birth.
“There was no treatment, there was not anything that couldhave changed the outcome,” Dr. Petrikin said “But we could have more
appropriately counseled the family and bypassed what had to have been intense suffering” . The baby, he explained, was heavily sedated,
medicated and intubated for her entire brief life. The idea behind the test is to take advantage of what is known about disease symptoms
to narrow the search for genetic aberrations. And that,said Dr. Joe Gray, an expert in genome analysis at Oregon Health and Science
University, “is a good step in the right direction.”
- “It’s a big genome,” said Dr. Gray, who was not involved with the study. “How do you know what part of it to search?” . While
more research needs to be done before the test is ready for widespread use, he applauded the effort. “If people don’t push theenvelope
like this, then we won’t get there,” Dr. Gray said. About one in 20 babies in newborn intensive care units has a genetic disease and all
too often, no one can figure out what it is. Scientists identified the faulty genes for about 3,500 of 7,500 known genetic diseases, said the
paper’s authors, adding that about 500 have treatments. To test their method, the investigators tried it with twobabies whose disease had
been diagnosed only through an autopsy. They quickly found the genetic causes. Then they tried the method on four babies who were
seriously ill with suspected genetic diseases, including the baby with seizures. They quickly found the mutated gene in three of the four.
The investigators also sequenced the DNA of an older brother of one of the babies who had thesame genetic disorder — his
organs were reversed. His heart was on the right, instead of the left, for example. This caused a heart defect that was corrected by
surgery. The parents had been told the child had a condition that would not happen again. Then their second baby had the same
problem. The researchers found a new genetic defect, never seen before, that they suspect was the cause. Theycontacted doctors and
discovered more than 100 other children with the same unexplained defect. Now the investigators are checking to see if some have the
mutation, which would indicate it caused the problem. Then the parents could know of a prenatal diagnosis for future pregnancies. The
baby whose disease remained a mystery was another of Dr. Petrikin’s patients. When he was born, some skin wasmissing over his
eyebrows and in patches on his scalp. Over weeks, he developed severe blistering, eventually losing nearly all the skin in his mouth and
on his body and dying of an infection.
“We still don’t know what caused it,” Dr. Petrikin said.
Traducción:
Prueba de ADN para Bebés Localiza mutaciones, diagnóstico exceso de velocidad.
Por Gina Kolata.
Publicado: octubre 3, 2012 10...