We still don't understand genetics and inheritance
New Genome Test Finds Big Differences Among People
Thu Jul 22, 2004 04:36 PM ET
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - A new way of comparing DNA has turned up surprising genetic differences among normal, healthy people, researchers said on Thursday.
The researchers found -- by accident -- that some people are missing large chunks of DNA, while others have extra copies of stretches of DNA.
Writing in the journal Science, the researchers have dubbed these differences "copy number polymorphisms." They are found in genes linked with cancer risk, with how much people eat and with reactions to drugs.
"Thus, a relationship between CNPs and susceptibility to health problems such as neurological disease, cancer, and obesity is an intriguing possibility," the researchers wrote in their report.
The team at Cold Spring Harbor Laboratory in New York, the Karolinska Institute in Stockholm, Sweden and elsewhere used a new kind of DNA test called Representational Oligonucleotide Microarray Analysis or ROMA.
"It can detect differences in DNA from any two sources," said Cold Spring Harbor spokesman Peter Sherwood.
The researchers were looking for genetic differences linked with cancer.
"As a control in the cancer experiment they compared normal to normal DNA, expecting it to be pretty much the same," Sherwood said in a telephone interview.
"They detected more than 70 of these large chunks of DNA that were altered in normal human cells."
These were large differences that have not been reported before -- involving much more DNA than so-called single nucleotide polymorphisms, which are well-known single-letter changes in the A, C, T, G nucleotide code that makes up DNA.
