Your genome and your physiology

Commemorating Professor K.N. Seneviratne:

Your genome is the instruction manual that nature used to make you. The manual came in the form of an acid called Deoxyribose Nucleic Acid or DNA. Your father and your mother joined together to compile the manual. Through a sperm your father contributed half of the instructions.

Through an ovum (egg) your mother contributed the other (probably better) half of the instructions. You began life when a sperm from your father fused with an ovum inside your mother’s body to form a single cell. That single cell developed into the one and only YOU> The point is that each of us has a unique genome.

But 99.9% of it is identical with the genome of other human beings. Why? Because we belong to the same species. Therefore, what makes you unique is the remainder, the tiny 0.1% of the genome. So - as in the lovely song - when you tell the one you truly love that you do so “for a hundred thousand reasons, but most of all because you are you” remember that just 0.1% of that person’s genome made the difference.

Genome

Your genome is made up of about 30,000 bits of DNA called genes. The miracle is that almost all the trillions of cells which constitute you, contain a copy of your genome. Each gene is like a blueprint for making a tiny component of your complicated body. Thus, your genome is like the set of blueprints in accordance with which you were created.

The Human Genome Project set out to crack the genetic code, that is to say, to figure out the order in which the different components of human DNA are arranged. This was accomplished in 2003.

The current interest in the genome derives from the fact that a few disorders such as Hemophilia and Parkinson’s disease have been traced to defects in single genes. What is more, some scientists claim to have discovered genes that make some people homosexual or criminal or alcoholic.

The truth, however, is neither so pure nor so simple. This year’s Professor K.N. Seneviratne Memorial Oration - the 21st in an annual series - will be delivered by Professor Kamani H. Tennekoon.

A pupil of Prof. KNS, she is a very accomplished medical scientist who currently occupies the Chair in Physiology which Prof. KNS adorned. In her oration she will examine the implications of the genome for our present understanding of how the human body works to keep itself alive and reproduce itself.

Academic Pedigree

Twenty-two years after his much lamented, untimely death the consensus is that Prof. KNS was the most distinguished physiologist Sri Lanka has produced up to date.

A straight-A student, KNS was successively an alumnus of Royal College, Colombo; University of Ceylon; and the University of Edinburgh. His PhD supervisor at Edinburgh was Professor David Whitteridge FRS, who was at that time the last surviving direct pupil of Oxford University’s famed Sir Charles Sherrington, Nobel Laureate, recipient of the Order of Merit and Fellow and later President of the Royal Society of London.

So Prof. KNS was in direct lineal intellectual descent from the great Sir Charles Sherrington himself. His academic pedigree was therefore impeccable. In 1968 he succeeded Prof. ACE Koch as Professor of Physiology in the Colombo Medical School and held the post with great distinction until 1981.

During that period, in 1974, almost single-handedly he also founded Sri Lanka’s Institute of Post Graduate Medicine which flourishes today as our prestigious Post Graduate Institute of Medicine (PGIM). In 1981 he joined the World Health Organization as a Regional Advisor and worked purposefully until his premature death in 1986.

Family Pedigree

Kirthi Nissanka Seneviratne was the second of the three children of Dr. Robert and Laura Seneviratne. Having qualified as a doctor in the Ceylon Medical College Dr. Robert Seneviratne went to Edinburgh, Scotland where he became a licentiate of the Royal College of Physicians and Surgeons.

His son KNS also trod the same path to Edinburgh and there acquired not only a higher doctorate but also a charming, highly educated Scottish lass, Alison Alexander as his partner in life. It is by her munificence that the Prof. KNS Oration became an annual event. It is with great sadness that her death this year is recorded here.

The other great supporter of the memory of Prof. KNS has been his younger brother Nihal Seneviratne who was for many years the Clerk of the House of Representatives.

Once when I openly envied KNS’s many blessings including high-powered family connections, he dryly remarked that contrary to what I said, his only brother is only a clerk! What he said was, of course, literally true. Delightful humor was only one of his many gifts.

Another was his power of lucid exposition. His lectures, delivered without a scrap of paper, were the gold standard of the art of lecturing in the Colombo Medical School in his time. One student who was inspired to specialise in physiology by Prof. KNS is this year’s KNS Memorial Orator Prof.

Kamani Tennekoon. I remember her well not only because she won the Gold Medal in Physiology in 1975, but also because she never asked me a question in physiology which I could answer without consulting an advanced textbook.

She specialised in Reproductive Endocrinology and is one of the most productive researchers in the Colombo Medical School. She was appointed Professor of Physiology in 2004. Currently she is the Director of the Institute of Biochemistry, Molecular Biology and Biotechnology in the University of Colombo.

Prof. Carlo Fonseka