What Are Genes?
When you cut yourself with a knife while preparing peppers, you feel the sting and visually see the separation of your skin in that area. Five days later after you’ve wrapped that part of your skin with a bandaid and cleaned it out, that separation is no longer. The area isn’t still bloody or pink and doesn’t hurt quite like it did that day. Your body healed itself and grew more cells to cover that area. It wasn’t magic. It was your body’s natural reaction to an injury. It was orchestrated by proteins that know how to fix the problem. And your genes are how the proteins came into existence knowing what to do. Our genes are the instruction manuals to our bodies. There are pages upon pages of instructions that tell the body how to heal from a cut or bruise, how to grow hair and a heart, and how to digest brownies. We have about 20,000 genes that are the foundation to who we are as humans. Other animals have more or less genes that tell those bodies how to grow and develop. In this post, we will go into more detail as to what genes are and their importance to our health.
What are genes, exactly..?
Our genes are made up of nucleotides. A nucleotide is a compound that can bind to other compounds to create the building blocks of DNA. The nucleotides form bonds with each other to create a string of them. There are four main nucleotides called guanine, adenine, thymine, and cytosine or G, A, T, and C for short. The below picture has the classic picture of our DNA or genes. You will see the colored bars that are supposed to represent each nucleotide. The chemical structure of the nucleotide is displayed below.
Three nucleotides in a row are called a codon. For example, if cytosine, adenine, and thymine were in a row together, they would be considered a codon. The codons are how our DNA gets read by the body. It is the code for proteins to come together.
Nucleotides are compounds that bond together to form our DNA. There are four main nucleotides: guanine, thymine, cytosine, and adenine.
Amino acids are the building blocks of proteins. Proteins carry out the intended function of the genes - they are the “workers” whereas the genes are the “managers” giving out instructions. A protein is made up of a string of amnio acids called a “polypeptide chain” that form and bind together to create a protein.
Amino acids are the building blocks of a protein. A string of amino acids is called a polypeptide chain. A polypeptide chain folds into a protein. A protein carries out the intended function of the gene.
A section of DNA in which the we know what protein it encodes for is called a gene. Genes are made up of certain nucleotides in a specific sequence like so: CATGGTTTAGGGGGGATGATCCTGTAG. This made up gene would be able to make a protein using amino acids as the building blocks and that protein would be able to do a key function in the body like make skin to cover a cut.
What is an example of a gene?
A real example of a gene is the CFTR gene. The CFTR gene makes a protein whose function is to let certain molecules inside and outside of the cell. A cell is bigger than a gene and many proteins. A cell is the unit that actually makes up our bodies. So our heart is made up of tons of cells. Our skin is made up of cells and so on. They are super small, so we can never see just one cell, but we are able to see the collection of cells that make up our skin, hair, nails, eyes, feet, etc.
Inside of the cells are mitochondria, lysosomes, nucleus, and other important structures. The nucleus is where our genes are located and are kept safe. The cell can have many functions and needs certain molecules to be able to do those functions. The CFTR protein is located on the outside of the cell and is like the doorman, letting only desired molecules in. If the CFTR gene does its job properly then the body functions how it should, such as maintaining the proper moisture levels in the lungs.
But...there can be a change to the nucleotide sequence that make up the CFTR gene that makes it unable to carry out its task. If the CFTR is not able to be the doorman of the cells that line the lungs, then the moisture levels are going to be incorrect and make the lungs sticky. When this happens, the person has a condition called cystic fibrosis. Their lungs are sticky and are not able to clear bacterial buildup that is caused by the air we breathe in. People with cystic fibrosis have trouble breathing, among other things (this is a simple view of the condition, check out: https://ghr.nlm.nih.gov/condition/cystic-fibrosis for more).
How does someone know if there is an issue with their gene?
If there is a change to the nucleotide sequence like a T replaces a G, then this could cause the protein to be made incorrectly or not at all. Genetic testing is the ability to look at someone’s nucleotide sequence of certain genes to identify if there has been any changes to the nucleotide sequence. Genetic testing makes sure there are no "spelling errors".
A common way people describe genetic testing is using the analogy of our genes being our instruction manuals. Genetic testing reads through the pages of the manual, looking for mistakes. The mistakes can be a word misspelled or a sentence deleted from the page that makes the page unreadable. If the change causes the gene not to function, it is called a mutation or a pathogenic variant. There are some changes or variants that are considered benign and others where the significance is not yet certain.
A genetic report can let you know if there are any changes and can let you know if those changes are considered benign or harmful. A genetic counselor can discuss the implication of the result to your health and reproduction.
Our ability to learn about our genes is relatively recent, and there is still a lot more to learn! Genetics is not always the most straight forward science, but, arguably, could be considered one of the most important areas for research to cure and treat disease.
* This blog constitutes general information about genetic testing and medical screening. This blog does not offer or provide medical advice or diagnosis, and nothing in this blog should be construed as medical advice or diagnosis. Do not rely on the information in this blog/article to make medical management decisions. Please consult with a medical professional before making those decisions. Do not delay in seeking professional medical advice if you think you have a medical concern. Do not disregard professional medical advice based on any information received in this blog.
