The quite fascinating field of genetics...

Cliched though the statement "Its all in the genes" may sound, it has always had a sense of mystery and intrigue about it. Of the myriad interests that i have, human physiology and genetics rank right up there..The very idea that almost all traits ranging from height, body constitution, physiological parameters right up to the more debatable finding that male homosexuality could be linked to a gene on the X chromosome has fascinated me endlessly..Genetics as a whole is an extremely vast subject but never falls short when it comes to arousing interest and enthusiasm..I have read quite a few books on physiology and genetics over the years but the one I chanced upon last week has been nothing short of a revelation..A random search at the British library led me to pick up this most amazing book titled DNA-The secret of life by James Watson of the double helix model fame..A great authority on the subject, Watson has at once made sure that this interesting yet complex subject is written in a manner which can be enjoyed by students and experts..

This classic book takes one step by step through the field of genetic research and developments..Right from the time Gregor Mendel worked on the pea plant and brought out the various aspects of genetic variations which have since proved to be the building block for future research to the work of Morgan on the Drosophila (fruit fly), there was a considerable increase in interest and prospects in the field..Hugely inspired by the book "What is life?" by the great physicist Erwin Schrodinger, James Watson and Crick negotiated several pitfalls and hurdles during their quest for determining the structure of the DNA which was deemed rightly to be the building block of life.. They came up with the double helix model which explained that DNA consisted of the four bases Adenine, Guanine, Thymine and Cytosine (A,G,T and C in short)..A combination of three bases was found to code for amino acids..Ribosomes in the cells use this information to produce proteins (chain of amino acids)...

Even more extraordinary in the all too amazing world of genes is the role played by evolution and the environment..There are particular traits which are more pronounced in certain populations..Genealogy is a most interesting field but one that has more questions than answers at the moment..

Gene cloning is another highly controversial yet advancing field..Modern means including the use of restriction enzymes to cut sequences and then attaching them to bacterial DNA (plasmids) using ligase enzymes and then obtaining multiple copies is one of the most widely used methods of cloning..The idea that it could be applied to humans to help in tackling genetic issues is still a topic that evokes much criticism from the conservative population..

The role of genetics played in solving crime cases is increasing by the day. DNA fingerprinting and forensic science have evolved greatly and modern approaches including short tandem repeats (STR's) wherein the fact that a sequence of bases repeats often in the sample is used to analyze and compare samples..The very fact that little evidence is sufficient to analyze samples means this technology assumes even more importance in the years to come..

Genes help transmit many favorable characteristics while at the same time due to mutations, missing sequences of amino acids and other modifications, the genetic information carried to the next generation can be flawed resulting in many genetic disorders..Some of them can be very common while some are very rare..There are a few diseases and disorders whose occurrence seems to be rather high in certain populations..The study of these and finding a cure for them is foremost on the agenda for modern genetic science..

Genetic flaws result in some of the most devastating disorders such as Down's syndrome, the cause of which has been found to be the presence of an extra chromosome 21 (known as Trisomy 21). From 1 in a few thousands, the probability of occurrence increases to less than 1 in 100 as the age of the mother nudges 40..Though this can be determined prenatally by various techniques such as Fluoroscent staining, it is still a rather difficult decision to choose between terminating the pregnancy and bringing up the affected child...

Huntington's chorea caused by a dominant gene is a serious mental disorder which affects mostly adults though early onset is possible...Slow mental degradation along with uncontrolled body movements inevitably lead to severe brain damage and death..There have been advances and the gene causing this has been localized but further progress is required to treat this fatal disorder..Hemophilia and Phenyl ketonuria (PKU) are other well known genetic diseases..The former is known as the "Royal disease' owing to its prevalence in members of the Royal Family of England and people affected bleed continuously when injured as blood clotting is impaired..PKU is caused by a recessive gene which makes its probability rather low..The body cannot metabolize the amino acid phenylalanine...But this is one disorder that can be controlled by an appropriate diet.. Sickle cell anemia is another genetic disorder affecting mostly African Americans. There is one amazing fact though.that people who carry the gene (unaffected) are also protected from Malaria.This goes to show how the mutations in a body's genetic constituency comes about as a result of the effect of evolution and the environment..

Breast cancer is found to be linked to mutation on the gene BRCA1 and early diagnosis is possible which helps prevent death..Advanced research has helped detect the link between various diseases and the genes in the body..The mapping of the human genome (The Human genome project) is a great venture and on completion with undoubtedly represent a path breaking achievement and holds the key to much of the future research in the field of gene therapy...

Gene therapy is at once a great ray of hope for the future..Missing sequences and faulty genes can be replaced and treated which might augur well for the lives of various affected people..Somatic gene therapy involves identifying, isolating and extracting the target cells and then infecting them with a virus (retrovirus) which contains the required functional gene..Once the natural DNA has the functional gene it is ready to be replaced in the body..This has so far been attempted in a very specific case of an immune disorder where the target cells were easily known and identified..The complexities involved are many and unless there are more definitive results and advancements, this superb concept will move slowly..Germ line gene therapy involves modifying the germ cells (sperm and egg) to help eliminate the possibility of disorder in future generations..Though seemingly a brilliant idea, the risks it involves makes the process rather dangerous..Gene replacement carries a risk of mutation and this might be extremely dangerous to the developing fetus..For now somatic therapy is the way to go..

Genetics and its various concepts and research makes it an extremely interesting field to read and an even more thrilling one to be part of..I sure hope to be able to lay my hands on some more great books such as the one by Watson so that I can stay abreast of the fantastic developments in genetic research..