What is the human genome? What is genomics?

What exactly is the human genome? Think of it like a big instruction manual for your body. Genetics is like reading just one page looking at a single gene. But genomics is like reading the whole book, seeing how all the pages connect and work together. Or imagine it like music, genetics is one instrument, while genomics is the whole orchestra playing in harmony. In this Health Tree University lesson, you'll learn how studying the myeloma genome helps doctors better understand your disease and create more personalized treatments. What is the human genome? What is genomics? Every individual's genome represents that DNA code that makes all of their traits unique. And that code is made up of units. In biology, the unit is called the base of DNA and there are four of them. We refer to them as A, G, C, and T. Those are just abbreviations for the chemical names of the bases of the DNA. And the order of those bases is different in different individuals and dictates individual traits. The number of those bases is about three billion. So every genome, every cell in your body has this code made up of three billion of these A, G, C, and T's. And it's the order of those that give you your traits. The important take-home lesson here is there's unique characteristics in all of us that is dictated by a unique sequence of our genome. So practically the human genome is the complete set of all the genetic materials or DNA that is present in human cells. So normally each individual, each person has 23 pairs of chromosomes. These are derived from their mom and their dad. And practically in total we have 20,000, 22,000 genes. Genomics is really the field of biology, of science that try to understand and focus and learn everything about the structure, the function, how DNA evolve and how does it change in normal and also in a cancer patient. So practically overall human genome contains all the DNA information that are important for each cells to grow, to keep doing their job and keep like existing. What is the myeloma genome? A genome is the genetic information encoded in an organism. Typically when we refer to myeloma genome, we are referring to the tumor cell which is having its own genetic information. This is different from the genetic information in say the patient's normal cells and that is what is transmitted from parents to children. Remember, in most cases myeloma is not transmitted in a hereditary fashion. It's a sporadic cancer and just to weave a little caveat into that, our team at Sinai led by Dr. Thibault has led a beautiful study looking at what genes are involved in familial myeloma and he has found that about a little less than 10% of patients can carry these genes and how to look for them and how to clinically suspect them. Let's think about the technologies that allow us to ask questions. Questions like how many genetic events, how many differences in this coding sequence are enough to cause a tumor in a plasma cell that becomes a myeloma. If we look at lots of different myelomas, do they all have the same changes in DNA or are there some that are common, some that are rare? Do some of those genetic changes affect how quickly the disease develops whereas maybe there are other genetic events that affect how a tumor might respond to therapy? Do these genetic events change over time? When a person is initially treated, they have a certain genetic characteristics of their tumor but maybe when they relapse, the tumor changed some of those genetic characteristics. It's important for us to ask those questions of the biology of the central code or the DNA. We want to be able to sequence that code in every individual, in every myeloma, in lots of different myelomas and maybe even myelomas over a period of time as the disease might progress or become resistant or in a relapse. Is it possible to sequence an entire genome of those three billion bases to get the code of every individual? If you would ask me that question 20 years ago, I would have said, no, you can't do it. Actually 20 years ago, the first code sequence of all three billion bases of a human was determined and it took 11 years and it cost research laboratories all around the world contributing to that. It cost about $3 billion. So to get one genome took 11 years and about $3 billion. Should we do that for every individual? Well obviously that's a silly question because we can't possibly do that for everybody or can we? In the last 20 years, the technology has developed with what we call this next generation sequencing technology. We now have the capability of sequencing that code of three billion units in every individual now it cost about $300, not $3 billion, and now it can be done in a day or two, not 11 years. That's pretty amazing development of technology that now allows us to ask those questions I was addressing. Are myelomas different at the genetic level? Are they different when they progress? Is an aggressive myeloma different than a smoldering myeloma in its genetic coding? Twenty years ago, couldn't possibly have asked that question. Today, with the technology that's available, we can ask those questions and start accumulating genome sequences of lots of different patients and myelomas. So what have we learned even in the last five years addressing these kinds of changes, this kind of information that the technology now gives us the capability to do? We know that there's lots of changes in DNA sequence. It's not just one gene going bad. It's lots of changes that occur in these myeloma cells. Some of the changes are common among lots of different patient myelomas, but others are very unique to individuals. Some of those changes we're now learning are associated with high risk disease or highly aggressive disease. That's a useful piece of information to say, if I understand the genetics of your tumor, I have a better idea of how aggressive your disease might be. And that's becoming useful information. How does genomics differ from genetics? Every cell has got 23 pairs of chromosomes, and those chromosomes are the genes. And when we talk about genomics, we talk about all of the genes in a cell. And when we talk about genetics or genetic testing, we talk about looking at individual genes. So it's really, they're talking about the same thing. It's just a difference of scale. And there's probably about 30, 40,000 genes. And often we're only concerned with a handful of them. If you found this Health Tree University lesson helpful, give us a like and subscribe to our channel. You can also watch the other lessons in this course on our YouTube playlist or on the Health Tree University website. To watch it on the website, go to the Health Tree University site, find the Myeloma Genetics Genomics Module, and then click on the Basics of Genetics and Tumor Biology course.