When mapping the genes there are two main techniques used, these are linkage mapping and physical mapping. Linkage mapping identifies ‘landmarks’ on a chromosome as genetic markers, which are unique DNA sequences and represents a position on the human genome. Physical mapping can place these ‘landmarks’ at specific distances from another and so is more precise. A landmark may be a gene, a genetic marker or any other DNA sequence.
The idea to undertake such a large and detailed project began between 1985 and1987 during a string of scientific conferences. Although the UK and US first put the idea in to practice, the project is now an international collaboration. These include France, Germany, other EU members, Japan and China. Within the UK there are three main sites of genome research, which are The Sanger Institute in Cambridgeshire, the European Bioinformatics Institute and the UK Genome Mapping Project Resource Centre.
In December of 1998 for the first time a whole genome sequence of an animal had been completed. The animal, a tiny worm, only consists of 1,000 cells it is very similar to a human in the way that it has muscle tissue, a nervous system, a digestive system, and it reproduces sexually. This development encouraged researchers that they would be able to sequence the 3 billion human base pairs that make up the human genome by 2003, two years ahead of schedule. By June 2000 the first working draft of the human genome was complete, and by February 2001 they had completed a detailed analysis of the draft. However the draft is not fully accurate.
Once completed, the human genome sequence will have a great affect on worldwide research into human diseases and how to cure them.
However as more and more is being discovered about our genes, we will have more and more choices regarding our genes. As we progress further in to the future the human genome sequence will not only be used in medicine but for cosmetic reasons as well.
Researchers have developed tests for hundreds of the genetic disorders that threaten the live of many people. These can diagnose disorders in children and they can also predict the chances of suffering from the disease later in life. Genetic tests can also help couples who want to know the risk of passing down a genetic disorder. They can also do a prenatal test that is done before the baby is born to check for any disorders. However sometimes once people know about the disorder and there is little they can do as a cure or treatment is not available as of yet. There is also the issue of who do they tell once they know they have the disorder, many people must come into consideration, their partner, their employer, their health insurance company. If after the test the information is put on their medical record then both their employer and health insurance company will find out. As a result they may lose their job or be denied health insurance. To help with all this there are genetic counsellors, they help people understand the facts and choices they have after receiving the tests. However more tests are coming out than genetic counsellors are being trained so not everyone is able to have counselling. Also as demand increases companies may begin to sell tests directly to the public and doctors instead of simply genetic specialists. As a result people will be getting important information without the right support afterwards.
People who choose to know about their genetics maybe faced with a lot of problems they may not want to get married or build a career as they feel there is no point, they may stop enjoying life altogether. The big issue is whether children should be told and if they should there must be an age limit as children when they are too young may not understand what it means and the consequences it initials. The other option is telling the parents and they can make their lifestyle choices for then. Society also plays a part through laws, regulations and standards that are made.
The bigger problem faced by some is when they lose their health insurance and a refused cover, sometimes even their children are refused cover as there is still the risk they may develop the disorder. This situation may become more common as genetic testing becomes more popular. Employers may also use the opportunity to fire workers who will one day not be able to do the job. As a result people may not want to carry out the test as they fear that the repercussions from it will be worse than not knowing if they have a genetic disorder or not.
People who do take the test may then realise they either have or are carrying a genetic disorder, and through gene therapy they may wish to insert new DNA into some cells that will then take over the disorder. However this change will not be passed down to the next generation. Researchers are looking in to germ-line therapy. This is when you could change the genes you pass down to your children and as a result it may be possible to eradicate a disorder from your whole family as your children, grandchildren and even great-grand children would be spared from the disease. However because when you change the germ line of one person you change the lives of many other people who are their descendants. And some of the people aren’t even born yet so they can give consent. Also this type of therapy may have unknown side effect on the foetus.
Some scientists think that behaviour and abilities are based on genetic makeup and influenced by the way people are raised. Some researchers are trying to find out whether of not intelligence is genetic or not, but the result could be very controversial as people may feel we should put more effort into the children who are not equipped with the clever gene as they need it. Some people however may feel that the genetically clever should be given education, as they will use it better. This kind of thought can be easily made into discrimination against certain people.
Privacy can be easily invaded once your DNA samples are on record. If a persons DNA was needed in a murder case to see if they were the murderer or not, and even if they weren’t their DNA would stay on record in a police data bank. As a result the police can find out things about them without them even knowing. They may then learn things about themselves they didn’t want to know. There is now a new law in England, where the police are able to take samples of DNA from suspect even without their permission. As a result England has created the worlds first nation-wide DNA data bank. Consequently someone’s DNA may end up on another database where your employer or health insurance company may get hold of it. And there are currently no laws controlling DNA files.
Overall there are many considerations to think about when looking at how the genome project will affect people. However I am sure once it is completed it will be a great asset to the world of medicine and science.
