Passage Fifteen
British regulators yesterday ruled that fertility clinics may screen out human embryos carrying genes that raise the risk of cancer in adulthood -- a move the government said could prevent future suffering but that others said was proof that the age of handpicked, "designer" babies is at hand.
The Human Fertilisation and Embryology Authority, which oversees tests involving human embryos in Britain, had previously allowed the use of genetic tests only to eliminate "test tube" embryos bearing genes for fatal childhood diseases.
The new decision expands that policy to include some genes that significantly increase the odds -- but do not guarantee -- that a person will get cancer. The policy also for the first time includes diseases -- primarily breast, ovarian and colon cancer -- that do not strike until adulthood and often respond to treatment.
Similar embryo screening tests have been used in the United States for years. But because they are not regulated or tracked, no one knows how often they are performed or the full range of conditions being screened for.
Some experts fear that as scientists discover genes affecting traits such as obesity, addiction, intelligence or height, a market in elective embryo screening may emerge -- backed by evidence that selected children would be healthier, happier and more successful.
The kind of testing in question, known as preimplantation genetic diagnosis, is conducted on one or two cells removed harmlessly from a three-day-old test tube embryo created by in vitro fertilization. If a cell is found to harbor an unwanted gene, that embryo is not used.
"The role of medicine has always been to try to relieve pain and suffering and to try to improve the quality of life for people," said HFEA chair Suzi Leather, in a statement. "The decision today deals only with serious genetic conditions that we have a single-gene test for. We would not consider mild conditions -- like asthma and eczema -- which can be well-managed. . . . We would not consider conditions like schizophrenia where a number of genes have been identified but there is no single gene that dictates the condition."
"It raises a number of obvious ethical issues," said Bert Vogelstein, a medical geneticist at Johns Hopkins University and a co-discoverer of the HNPCC gene. Most people he has spoken with, including patients and their relatives, don't think embryo screening for the disease is justified, Vogelstein said. "But there are some who have seen their families devastated by these diseases . . . and they are not so sure."
1. To what tests did there exist pros and cons in Britain according to Paragraph One?
A. Embryo screening of gene
B .Discarding unfavorable embryo
C. Genes discovering.
D. None of above.
2. Why did HFEA allow genetic tests be conducted previously?
A. Because it can create clever and smart babies in future.
B. Because it can prevent the suffering of incurable disease.
C. Because it may exclude genes potential to fatal disease.
D. Because it is the progress of embryo research.
3. How can we conduct embryo-screening tests according to the passage?
A. The removal of unwanted gene from cells of embryo in vitro fertilization
B. By taking cells out of embryo from human fertilization
C. By using the un-harbored gene from cells taken from embryo
D. By decoding the unwanted gene from embryo of human fertilization.
4. Why schizophrenia was not identified through single-gene test?
A. Because it is not easy to suffer.
B. Because there are a number of genes to be tested to schizophrenia.
C. Because it can not be managed.
D. Because children are not prone to suffer.
5. From this passage, we can conclude that _______.
A. embryo screening is approved by both scientists and patients.
B. genetic tests is a scientific progress in that it can produce healthy babies.
C. while it may exclude unwanted genes, embryo screening has raised ethic problems.
D. unhealthy genes should be exterminated in time against potential fatal illness.
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