A recent study showed that human DNA is far more different from one individual to another that it was previously thought and might hold the key to some diseases’ genetic origins.
A recent study showed that human DNA is far more different from one individual to another that it was previously thought and might hold the key to some diseases’ genetic origins. The research made by a UK-led team of scientists, compared the genomes of 270 people revealing that humans are not 99.9 per cent genetically identical as it was assumed before, in fact, human DNA shows plenty variations from one human to another.
The researchers were astonished to locate 1,447 copy number variants (CNVs) in nearly 2,900 genes, the starting "templates" written in the code that are used by cells to make the proteins which drive our bodies. "Each one of us has a unique pattern of gains and losses of complete sections of DNA," said Matthew Hurles, of the UK's Wellcome Trust Sanger Institute.
"One of the real surprises of these results was just how much of our DNA varies in copy number. We estimate this to be at least 12% of the genome. "The copy number variation that researchers had seen before was simply the tip of the iceberg, while the bulk lay submerged, undetected.
We now appreciate the immense contribution of this phenomenon to genetic differences between individuals." "We have a common heritage through our common humanity, but we also have a lot of differences that make us unique," says Scherer, director of the Centre for Applied Genomics at the Hospital for Sick Children in Toronto and a co-principal investigator of the research.
"Now we have more biology to explain the differences between brothers or cousins or spouses." Each person inherits 46 chromosomes, 23 from each parent, which means that genes usually come in pairs. But not always, according to Scherer.
"What we found in this study of 270 individuals worldwide is that up to 10 percent of the genes are actually present vary from the general two that we usually see," he said. "So, in some cases there's one. In some cases there's three. In some cases there's five. In some cases, there's actually none."
The consequences of these results could be far-reaching for medical diagnosis, new drugs and the tale of human evolution itself. The newly discovered genome map could help identifying the genetic origins of diseases, including heart disease, diabetes, Alzheimer's and various cancers. It represents the explanation why some individuals are more vulnerable to certain diseases or respond better to drugs than others.
The extra variation also expands the ways in which a person's DNA profile can affect temperament and behavior, and points to previously unknown genetic differences between homo sapiens and our closest animal relative, the chimpanzee. According to Tom Hudson, president and scientific director of the new Ontario Institute for Cancer Research, the map is set to be used in 20,000 labs worldwide. Often dubbed the Book of Life, the human genome is made up of about three billion letters (chemical base-pairs called nucleotides). Each of its 30,000 pages (or 30,000 genes) contains about 100,000 letters each.
Previously it was believed that genetic variations among individuals occurred because of alterations in single letters that changed the "spelling" of words. This study shows that variations - whether additions or deletions - affect not only single “letters,” but also sentences, paragraphs and even whole pages of the genome. "And now we're seeing in some cases that you get only one page, in some cases you get three, in some cases you get four, and in rare cases you have zero," said Scherer.
"Some genes or some pages of the encyclopedia are absolutely missing." The astonishing results are believed to be the very early stages of a new way to think about evolution. "I believe this paper will change forever the field of human genetics," said James Lupski, vice chair of the Department of Molecular and Human Genetics at the Baylor College of Medicine in Houston, Texas. "One can no longer consider human traits as resulting primarily from single base-pair changes or influenced only by SNPs."(single nucleotide polymorphisms)
From
http://www.playfuls.com/news_003044_New_Human_Genome_Map_Revealed.html
A recent study showed that human DNA is far more different from one individual to another that it was previously thought and might hold the key to some diseases’ genetic origins. The research made by a UK-led team of scientists, compared the genomes of 270 people revealing that humans are not 99.9 per cent genetically identical as it was assumed before, in fact, human DNA shows plenty variations from one human to another.
The researchers were astonished to locate 1,447 copy number variants (CNVs) in nearly 2,900 genes, the starting "templates" written in the code that are used by cells to make the proteins which drive our bodies. "Each one of us has a unique pattern of gains and losses of complete sections of DNA," said Matthew Hurles, of the UK's Wellcome Trust Sanger Institute.
"One of the real surprises of these results was just how much of our DNA varies in copy number. We estimate this to be at least 12% of the genome. "The copy number variation that researchers had seen before was simply the tip of the iceberg, while the bulk lay submerged, undetected.
We now appreciate the immense contribution of this phenomenon to genetic differences between individuals." "We have a common heritage through our common humanity, but we also have a lot of differences that make us unique," says Scherer, director of the Centre for Applied Genomics at the Hospital for Sick Children in Toronto and a co-principal investigator of the research.
"Now we have more biology to explain the differences between brothers or cousins or spouses." Each person inherits 46 chromosomes, 23 from each parent, which means that genes usually come in pairs. But not always, according to Scherer.
"What we found in this study of 270 individuals worldwide is that up to 10 percent of the genes are actually present vary from the general two that we usually see," he said. "So, in some cases there's one. In some cases there's three. In some cases there's five. In some cases, there's actually none."
The consequences of these results could be far-reaching for medical diagnosis, new drugs and the tale of human evolution itself. The newly discovered genome map could help identifying the genetic origins of diseases, including heart disease, diabetes, Alzheimer's and various cancers. It represents the explanation why some individuals are more vulnerable to certain diseases or respond better to drugs than others.
The extra variation also expands the ways in which a person's DNA profile can affect temperament and behavior, and points to previously unknown genetic differences between homo sapiens and our closest animal relative, the chimpanzee. According to Tom Hudson, president and scientific director of the new Ontario Institute for Cancer Research, the map is set to be used in 20,000 labs worldwide. Often dubbed the Book of Life, the human genome is made up of about three billion letters (chemical base-pairs called nucleotides). Each of its 30,000 pages (or 30,000 genes) contains about 100,000 letters each.
Previously it was believed that genetic variations among individuals occurred because of alterations in single letters that changed the "spelling" of words. This study shows that variations - whether additions or deletions - affect not only single “letters,” but also sentences, paragraphs and even whole pages of the genome. "And now we're seeing in some cases that you get only one page, in some cases you get three, in some cases you get four, and in rare cases you have zero," said Scherer.
"Some genes or some pages of the encyclopedia are absolutely missing." The astonishing results are believed to be the very early stages of a new way to think about evolution. "I believe this paper will change forever the field of human genetics," said James Lupski, vice chair of the Department of Molecular and Human Genetics at the Baylor College of Medicine in Houston, Texas. "One can no longer consider human traits as resulting primarily from single base-pair changes or influenced only by SNPs."(single nucleotide polymorphisms)
From
http://www.playfuls.com/news_003044_New_Human_Genome_Map_Revealed.html
posted by Dr. John Baker,DC at 5:04 PM
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