Nearly everyone is aware of DNA testing and understands at least the basics of what it means for homicidal criminals and geneticists alike. Understanding of genetic markers has opened the door for medical personnel and detectives as it allows them to winnow down features and traits to individuals and families. In the 1960s and 70s the best that could be done was to identify broad groups of the population; this allowed a lot of deficiencies and diseases, not to mention criminals, to slip through the cracks. DNA testing has a number of uses, including: constructing family trees, identifying hereditary conditions, solving crimes and identifying if an unborn child has any potential medical problems.
Constructing family trees
Medical researchers are endlessly fascinated by the potential offered by our relatively new-found ability to study genes and cells at the molecular level. Not only do these abilities allow for minutely accurate paternity tests to be done – enabling children to know exactly who their father is, and what genetic anomalies or predispositions he may have passed on, but they allow ancestry and genealogy experts to trace families back through many more generations than previously believed possible. This allows people to trace their family tree back to seminal world-wide events and beyond, offering a glimpse of distant ancestors, and maybe even reconnecting up long-lost branches of the family.
Identifying hereditary conditions
This type of family genealogy is usually thought of as being interesting, but not terribly important. This point of view is not accurate, as the case of the Long QT Syndrome. Long QT Syndrome is a serious heart defect which can cause sudden, apparently unexplained death – sometimes following a fright or upset, such as a teacher shouting at a pupil. The genetic component of this disease was discovered by a lady who was researching her family tree. She noticed that an awfully high percentage of one particular line of the family tended to drop dead with little or no warning. She took her finding to a medical friend who immediately saw the pattern. His research and publication of the syndrome led to greater understanding of the genetic element of the condition. There is now an International Long QT Registry where pedigrees and families can be documented. The registry has helped to advance genetic mapping all over the world.
In the event of serious crime, laboratory testing of evidence can irrefutably eliminate or implicate suspects, allowing policemen and prosecutors greater certainty in the event of a trial. Blood evidence in particular has grown from basic blood typing, which essentially divided the suspect pool into four broad groupings, to genetic screening which can tell officials that the person of interest is, for example, male, Caucasian, with blond hair and brown eyes – almost a snapshot of the perpetrator given up by a drop or two of his blood!
Identifying potential medical conditions in children
Where DNA screening really takes off though, is in its application in modern medicine. The ability to examine blood and 'see' the potential medical future of a child can help the parents and the child to deal with, discuss and plan for future illness. There is controversy about testing embryos in utero, but it can help parents to opt for a termination in the event that their child will be born with severe problems and the strong likelihood of an early death after a very poor quality life. It can also help doctors determine if there are genetic issues which will need treatment as soon as the baby is born, helping them prepare for the surgery, which will boost the child's chances of survival.
There are those who would apply genetic testing for frivolous reasons, those wanting a boy, not a girl, or wanting a 'designer' baby who will be particularly beautiful, healthy, tall or athletic. Many people feel that such checks should be reserved for life- or quality-of-life-threatening conditions, but it is very hard to draw the line on such a contentious issue.
In summary DNA testing is very useful:
- We can check for a wide array of diseases and conditions
- We now have greater understanding of hereditary conditions
- It is useful for crime solving, family tracing and medical research