August 1, 2009 - I believe the beginning of this century will be known as the “Age of Genetics,” just as the end of the past century has been called the “Information Age.”
The human genome—the genetic material of an organism—project was started in the mid 1980s, culminating in completion of the sequence of slightly over 92% of the human genes in 2003. Human genes are composed of only four different building blocks. The order of these building blocks provides the code for how information is carried from one generation to the next and how each cell in the body functions.
Essentially the idea was to unravel the mystery of how human traits are carried from one generation to the next, who will be susceptible to which illnesses, and how a person's genes will impact the efficacy of various treatments.
According to recent New England Journal of Medicine articles and editorials, “The human genome has been cracked wide open in recent years and is spilling many of its secrets.” Scores of common diseases—such as adult onset diabetes, rheumatoid arthritis, cystic fibrosis, Huntington's disease, some forms of cancer and other serious illnesses and conditions—all have some unique “genetic fingerprints.” Even height is related to several gene sequences.
The human gene is very complex and very interesting. Humans have about 30,000 genes, the number and type of gene sequences very similar to that of mice. This fact makes the use of mice very effective in genetic experiments. In fact, the prestigious Jackson Laboratories in Bar Harbor, Maine has capitalized on these similarities and are recognized for world class research on genetics as relates to human illnesses and treatments.
The male sex chromosome—known as the “Y” chromosome—is twice as likely to have spontaneous changes, or mutations. These new combinations are more apt to be responsible for genetic disorders.
There are many types of genetic diseases which have been well understood for centuries. An example is one type of hemophilia related to the sex chromosomes, in which the sons in a family have a 50% chance of being “bleeders.” This was the case of Alexis, son of Russian Czar Nicholas II, who inherited the gene from his mother, who had inherited it from her grandmother, English Queen Victoria.
With time, much more will be understood about how genetic mapping can help with early diagnosis as those people predisposed to a particular disease will undergo early and frequent surveillance. With early diagnosis, treatment is usually more effective.
Even with early diagnosis as a help for ultimate prognosis, determining which medicines or treatments will be most effective, or conversely, have side effects, will be determined by the genetic make-up of the person.
Of course, ethical issues will be raised as is always the case with new technology. With time, society will understand the role of this new scientific power, subsequently harnessing the technology for the good of individuals and society in general.
Genetics tells us how our body works, who will be afflicted with which disease, and how we will respond to treatment. The age of genetics promises to be the most exciting time ever for medical science.