Scientists have completed the final analysis of two more human chromosomes, packed with genetic information about cancer, diabetes and other diseases, in a major step toward developing personalized antidotes.
Chromosome 19 with nearly 1,500 genes, including ones linked to inherited high cholesterol and insulin-resistant diabetes, is the most gene-dense of those sequenced so far.
By contrast chromosome 13 has one of the lowest concentrations of genes with only 633. But they include the BRCA2 gene linked to breast cancer and others for the eye tumor retinoblastoma, bipolar disorder and schizophrenia.
“Having this sort of information out there is going to make life so much easier for a lot of people,” said Dr. Andrew Dunham, of the Wellcome Trust Sanger Institute in Hinxton, England, which mapped chromosome 13.
Sequences available on the Internet
An international team of scientists has already sequenced the human genome, the complete list of coded instructions needed to make a person.
Researchers are now analyzing each of the 23 pairs of human chromosomes, strands of tightly packaged DNA, to accelerate medical research and learn how to prevent and treat genetic diseases.
The sequences of chromosomes 19 and 13, which are published in the latest edition of the science journal Nature, will be freely available on the Internet.
Although chromosome 13 has a relatively small number of genes, Dunham said its barren areas may hold secrets and could control gene activity.
“We have a clear image of regions that do not code for genes, but are shared with other species, and it is clear that some of these will encode regulatory messages,” he said in an interview.
Chromosome 19, which was sequenced by scientists from the U.S. Department of Energy Joint Genome Institute and Stanford University in California, represents about two percent of the human genome but has plenty of genes.
A network of genes that control DNA repair after exposure to radiation and other environmental pollutants are located on chromosome 19.
“With this high quality sequence now made freely available to the scientific community, more light will be shed on individual responses to medicine,” said U.S. Energy Secretary Spencer Abraham in a statement.
“This will enable the development of more sensitive diagnostics for susceptibility to a wide array of important diseases,” he said.