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| 'One-stop' embryo test unveiled | 'One-stop' embryo test unveiled |
| (about 1 hour later) | |
| A gene mapping test could tell parents-to-be if embryos are affected by almost any inherited disease, UK scientists have claimed. | A gene mapping test could tell parents-to-be if embryos are affected by almost any inherited disease, UK scientists have claimed. |
| The team from London's Bridge Centre say the £1,500 test could detect any of the 15,000 inherited diseases in weeks. | The team from London's Bridge Centre say the £1,500 test could detect any of the 15,000 inherited diseases in weeks. |
| Current tests are either focused on a specific gene mutation, or take a lot longer to give results. | |
| But other experts warned the fertility regulator would have to ensure there were strict limits on the test's use. | But other experts warned the fertility regulator would have to ensure there were strict limits on the test's use. |
| If you can screen for anything, where do you draw the line? Dr Mark Hamilton, British Fertility Society | If you can screen for anything, where do you draw the line? Dr Mark Hamilton, British Fertility Society |
| At the moment, clinics can test embryos before they are implanted in a woman's womb to see if they carry a specific genetic mutation, if a family is affected by a condition such as cystic fibrosis. | At the moment, clinics can test embryos before they are implanted in a woman's womb to see if they carry a specific genetic mutation, if a family is affected by a condition such as cystic fibrosis. |
| Another test was developed by a team at Guy's Hospital in London two years ago, which looks at genetic "fingerprint" by looking at a whole DNA of a cell. | Another test was developed by a team at Guy's Hospital in London two years ago, which looks at genetic "fingerprint" by looking at a whole DNA of a cell. |
| But the claims for this new technique, called karyomapping which analyses chromosomes, is that it is a universal 'one size fits all' test. | But the claims for this new technique, called karyomapping which analyses chromosomes, is that it is a universal 'one size fits all' test. |
| Mapping patterns | Mapping patterns |
| A single-cell is taken from an eight-day-old embryo, created using IVF. | A single-cell is taken from an eight-day-old embryo, created using IVF. |
| DNA samples are then taken from the parents - and their parents. | DNA samples are then taken from the parents - and their parents. |
| Usually, another member of the family, most likely a child affected by the relevant condition, also provides a sample. | Usually, another member of the family, most likely a child affected by the relevant condition, also provides a sample. |
| All those family members' DNA is then compared, looking at 300,000 specific DNA markers, allowing scientists create a map of the family's genetics. | All those family members' DNA is then compared, looking at 300,000 specific DNA markers, allowing scientists create a map of the family's genetics. |
| This means they can, for example, identify if there is a block of DNA which has been passed on by the paternal grandfather to an affected child and if it is also present in the embryo - because the markers will be the same for all three. | This means they can, for example, identify if there is a block of DNA which has been passed on by the paternal grandfather to an affected child and if it is also present in the embryo - because the markers will be the same for all three. |
| For example, the gene for cystic fibrosis lies on chromosome 7. If the paternal grandfather was a carrier, and the embryo has inherited a section of DNA at that particular position, the embryo will have the faulty gene. | For example, the gene for cystic fibrosis lies on chromosome 7. If the paternal grandfather was a carrier, and the embryo has inherited a section of DNA at that particular position, the embryo will have the faulty gene. |
| The same check can be carried out across all chromosomes to allow screening for multiple genes. | The same check can be carried out across all chromosomes to allow screening for multiple genes. |
| 'Preventing suffering' | 'Preventing suffering' |
| Professor Alan Handyside, who has developed the test, told the BBC: "The current tests can only identify a small number of defects." | Professor Alan Handyside, who has developed the test, told the BBC: "The current tests can only identify a small number of defects." |
| "One of the main things for patients is that, quite often, there isn't a test for their particular condition. This is a single test - a universal method." | "One of the main things for patients is that, quite often, there isn't a test for their particular condition. This is a single test - a universal method." |
| He said the test could also be used, more controversially, to detect a genetic profile which showed a susceptibility to conditions such as heart disease or cancer. | He said the test could also be used, more controversially, to detect a genetic profile which showed a susceptibility to conditions such as heart disease or cancer. |
| The test is currently being trialled at the Bridge Centre, but is being used alongside conventional pre-implantation genetic testing so doctors can check the results. | The test is currently being trialled at the Bridge Centre, but is being used alongside conventional pre-implantation genetic testing so doctors can check the results. |
| Once Professor Handyside has enough data he will need to apply to the fertility regulator, the Human Fertility and Embryology Authority, for a licence to use the test. | Once Professor Handyside has enough data he will need to apply to the fertility regulator, the Human Fertility and Embryology Authority, for a licence to use the test. |
| An HFEA spokeswoman said its licensing committee would be able to set conditions on what it could be used for. | An HFEA spokeswoman said its licensing committee would be able to set conditions on what it could be used for. |
| Dr Mark Hamilton, chairman of the British Fertility Society, said: "The effectiveness and efficiency of the procedure is quite exciting, and the fact it's quicker means it could be helpful to couples at risk of inherited diseases - and that in itself is significant. | Dr Mark Hamilton, chairman of the British Fertility Society, said: "The effectiveness and efficiency of the procedure is quite exciting, and the fact it's quicker means it could be helpful to couples at risk of inherited diseases - and that in itself is significant. |
| "We can currently test for several hundred conditions, but the claim is that the spectrum of conditions which could be screened for is enormous | "We can currently test for several hundred conditions, but the claim is that the spectrum of conditions which could be screened for is enormous |
| "But obviously, the ethical question is, if you can screen for anything, where do you draw the line?" | "But obviously, the ethical question is, if you can screen for anything, where do you draw the line?" |