GENETICS 101

A Foundation for Understanding the KRAS-Variant

Why do we care about DNA?

The KRAS-variant is an inherited genetic mutationmeaning that it is found in your DNA, or your “genetic material” and passed to you from at least one of your parents. It is this small difference, or mutation in your DNA, that plays a part in increasing cancer risk, and maybe in changing your immune system.

An understanding of DNA, and basic genetics will help us understand the mechanism behind the KRAS-variant.

 

Chromosomes, DNA & Genes

3 facts you should know about DNA

1

DNA is your body’s textbook, and the carrier of all your genetic information.

“DNA is the textbook in every single one of your cells that tells you how to be who you are and tells your cells to do the tasks they need to do.” -Joanne, “Hormones, The KRAS-Variant & Breast Cancer Risk” webinar available on mirakind.org

2

DNA is unique to every individual.

*Fun Fact: as is widely known, identical twins come from the same fertilized egg, which causes them to carry the same DNA. Any differences between identical twins can thus be attributed to environmental factors, often those that lead to chemical modifications in the DNA (epigenetic changes).

3

DNA is inherited, or passed from parent to offspring.

You receive one copy of DNA from your mother, and one copy from your father…in the form of chromosomes.

 

What are genes and chromosomes?

Genes are segments of DNA which provide the instructions or detailed codes for specific traits, or qualities that you have.

Humans have approximately 24,000 different types of genes.

Chromosomes are like the carriers for your DNA, containing hundreds to thousands of genes which are packaged into long strands of tightly coiled DNA, capable of being stored in the nucleus of each of your cells.

Humans have 23 pairs of chromosomes. The genes contained in 22 out of these 23 pairs of chromosomes code for basic traits (e.g. hair and eye color, left or right-handedness, etc.) and proteins utilized by your body. The final pair is known as the “sex chromosome,” as they contain the genes that determine your gender.

How do genes get expressed?

Your genes provide the “codes” or “instructions” for the production of certain proteins.

Each protein has a distinct job, whether it’s to serve as an enzyme such as lactase, which breaks down the lactose in milk and other dairy products you may consume; to provide structure to your muscles and organs; or, perhaps to repair those tissues after you’ve experienced an injury.

Ultimately, these proteins, or gene products, are part of a collective effort to promote the expression of physical characteristics as a child develops, and to maintain that individual’s health as they age.

What is the central dogma?


The Central Dogma

DNA → RNA → Protein

The central dogma describes the processes—turning DNA into protein, called transcription and translation—that convert a gene on a strand of DNA into a functional protein that is capable of serving a variety of biological functions in the body. These processes occur continuously in the cells of our bodies in order to generate proteins that can do their respective jobs.

However, in recent years, this paradigm has shifted dramatically, with the discovery that DNA can make RNA molecules that never turn into proteins. This new type type of RNA is called “non-coding RNA”, and appears to be the master controllers of cells and their proteins. These discoveries have changed our fundamental understanding of biology, and have also led to discoveries, such as the KRAS-variant.

Transcription

DNA → RNA

The process by which a gene gets copied into an RNA intermediate molecule.

Translation

RNA → Protein

The process involving the formation of a protein from an RNA sequence.

Why is genetics important for understanding the KRAS-variant?

Since the KRAS-variant is a heritable mutation, meaning that it gets passed from parent to offspring in your DNA, it is important to understand this basic language about DNA and genetics.

Learn more about gene mutations and the KRAS-variant here.