What are the benefits of genetic testing?
Genetic testing has potential benefits whether the results are positive or negative for a gene mutation. Test results can provide a sense of relief from uncertainty and help people make informed decisions about managing their health care. For example, a negative result can eliminate the need for unnecessary check-ups and screening tests in some cases. A positive result can direct a person toward available prevention, monitoring, and treatment options. Some test results can also help people make decisions about having children. New-born screening can identify genetic disorders early in life so treatment can be started as early as possible.
I heard many times from people, “I don’t want to know”. I can understand this, but me for example, I had my full genome analysed. It took 12 years to analyse the human genome for the very first time. It did cost approx. 2 Billion USD, it was published in 2005. About 7 years ago, Steve Jobs was one of the first persons having his genome analysed. He paid 165’000 USD. Today you can have it done just below 1000 USD.
So, what did I learn:
I have a genetic pre-disposition for Diabetes Type 2, my blood pressure might get high if I am not taking care, I have a pre-disposition for skin cancer and a pre-disposition for glaucoma.
I learned a lot about what shall be my best diet and how, based on my genetics I can control weight. I learned about my special talents in sports and about my ancestry. The latter was just a nice add on and quite interesting.
Most important, I know to which medication I will be responding and which ones not. This is called Pharmacogenomics. And this is very important. I was taking medications that actually never worked (Omeprazole) and when I had surgeries, I was given a blood thinning medication (Warfarin) that had absolutely no effect on me. Today we can analyse over 500 commonly prescribed medications – everyone should do that and share it with their Doctors before accepting any medication.
But what do I do with all that information:
First: When I go to my annual medical check-up – and I recommend, that as of the age of 30, everybody should do such a check-up – I tell me Doctor to check for my weaknesses – skin, diabetes glaucoma, next to the one size fits all programs they offer in the clinic.
It would allow me to detect a problem at least early enough to act. Please remember, most of the cancers, if detected, early have a 95 percent chance to be cured. Unfortunately, most are detected in stage 4, meaning late or even too late.
Second: I can take some preventive measures. I have learned how to eat healthier, I do more exercise. You may say, we all know that. Yes, you are right, but in my case, before knowing my risk status – what I call my weaknesses, I wasn’t motivated, today I am.
Did you know, that it is written in your genes, if being overweight is mainly due to carbohydrates or fats. Well, I was always told to reduce the carbs – in fact my issue is with the fats. I am missing an enzyme that disintegrates fats in my body.
Third: Before accepting a medication, I check with the Doctor if I will be responsive or not.
Remember, if you have read my first post, in Big Pharma we launched medications to everyone having the same medical condition. We realized that not all will benefit. We didn’t know at the time that we can ask genetics to find out who will be and who not. We thought we must repeat clinical trials with sub-group of people, those would have been very expensive and not conclusive. Today, since the genome revolution, we have a tool to find out.
Especially in cancer, so many people get chemotherapy that they are not responding too, just suffering the bad side effects.
Genetics is therefore a key element of Precision medicine, individualized medicine.
I will write and summary some articles about the basics of genetics and let you know what videos I am finding interesting, that you should watch as well.
Let the journey begin
You and me, we are approximately 100 Trillion Cells. All of them have in the centre a Nucleus, and within this special compartment, 46 Chromosomes, which contain the DNA.A stretch of the DNA is called a gene.
What is DNA?
DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is in the cell nucleus (the centre of the cell), but a small amount of DNA can also be found in the mitochondria (the energy plant of the cell).
The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, like the way in which letters of the alphabet appear in a certain order to form words and sentences.
DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.
An important property of DNA is that it can replicate or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.
DNA is a double helix formed by base pairs attached to a sugar-phosphate backbone.
Credit: U.S. National Library of Medicine
What is a cell?
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions. Cells also contain the body’s hereditary material and can make copies of themselves.
Cells have many parts, each with a different function. Some of these parts, called organelles, are specialized structures that perform certain tasks within the cell. Human cells contain the following major parts, listed in alphabetical order:
Let me introduce you to a fantastic video I found on You Tube
The DNA Instruction Manual
How do cells divide? Please watch the video by Frank Gregorio
Cell Division and the Cell Cycle
What is a gene?
A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases. The Human Genome Project has estimated that humans have between 20,000 and 25,000 genes. The consensus now is, we have 20’000 genes, but as they come in pairs, we have 40’000.
Every person has two copies of each gene, one inherited from each parent. Most genes are the same in all people, but a small number of genes (less than 1 percent of the total) are slightly different between people. Alleles are forms of the same gene with small differences in their sequence of DNA bases. These small differences contribute to each person’s unique physical features.
Genes are made up of DNA. Each chromosome contains many genes.
What is a genome?
A genome is an organism’s complete set of DNA, including all of its genes. Each genome contains all the information needed to build and maintain that organism. In humans, a copy of the entire genome—more than 3 billion DNA base pairs—is contained in all cells that have a nucleus.
Code For Life: The Human Genome
What is the difference between: Genetics vs. Genomics?
Genetics and Genomics are two terms that are often incorrectly used interchangeably. Genetics is the study of single genes and their role in the way traits or conditions are passed from one generation to the next. Genomics is a term that describes the study of all parts of an organism’s genes.
Genetics is a scientific study of the effects that genes — which are units of heredity — have on an individual. Genes hold information in the molecule DNA, which is a string of chemicals called bases. The order, or sequence, of bases on the string determines the meaning of a genetic message. The message contains instructions for making proteins, which, in turn, direct cells and functions of the body. Humans have thousands of genes that are packaged into 23 pairs of chromosomes.
All the genes of an organism taken together, plus all of the sequences and information contained therein, are called the genome. The human genome consists of all of the thousands of genes (20’000 ) and the 23 chromosome pairs. Genomics includes study of how the genes within the genome interact with each other and with the individual’s environment.
Researchers may conduct genetic or genomic tests. Genetic testing is when the researchers investigate a single piece of genetic information for specific bits of DNA with a known function. By investigating a single known entity, scientists may isolate the underlying causes of the specific genetic variant in question. Genomic testing is broader, with no target. Genomic testing involves investigating large sections of genetic material and information, from which broad or specific conclusions may be drawn.
Some examples of genetic or inherited disorders include cystic fibrosis, Down syndrome, haemophilia, Huntington’s disease, phenylketonuria (PKU) and sickle-cell disease.
Some disorders and complex diseases that have been studied in the field of genomics include asthma, cancer, diabetes and heart disease. These diseases are caused by a combination of genetic and environmental factors, rather than simply a single genetic defect. The study of genomics has provided the medical community with new diagnostic tools and therapies for these complex diseases.
What is a chromosome?
In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.
Chromosomes are not visible in the cell’s nucleus—not even under a microscope—when the cell is not dividing. However, the DNA that makes up chromosomes becomes more tightly packed during cell division and is then visible under a microscope. Most of what researchers know about chromosomes was learned by observing chromosomes during cell division.
Each chromosome has a constriction point called the centromere, which divides the chromosome into two sections, or “arms.” The short arm of the chromosome is labelled the “p arm.” The long arm of the chromosome is labelled the “q arm.” The location of the centromere on each chromosome gives the chromosome its characteristic shape and can be used to help describe the location of specific genes.
DNA and histone proteins are packaged into structures called chromosomes.
Credit: U.S. National Library of Medicine
How many chromosomes do people have?
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome, while males have one X and one Y chromosome.
The 22 autosomes are numbered by size. The other two chromosomes, X and Y, are the sex chromosomes. This picture of the human chromosomes lined up in pairs is called a karyotype.
Credit: U.S. National Library of Medicine
From DNA to protein – 3D
Next time I will talk about
Gene mutations and how the affect health, and what you can.
BR, 22.02 2019