|The Human Genome Sequence Measures Up|
By Kate Ruder
Posted: August 19, 2004
The human genome sequence is up to snuff. The largest examination to date of the quality of the “finished” human genome sequence was recently completed, and the DNA sequences surveyed meet or exceed the international standards for accuracy.
This is the first large-scale assessment of sequences that were deposited online by seven different sequencing centers throughout the world as part of the Human Genome Project in 2001 and 2002.
Jeremy Schmutz of Stanford Human Genome Center in Palo Alto, California, led the study. His team analyzed roughly 34 million letters of genetic code out of the three billion letters in the human genome sequence.
Schmutz and his colleagues found that all sequences are of high-quality and meet standards for “finished” sequences established in 1997. Finished sequences are nearly perfect and have less than one error per 10,000 letters of genetic code.
“Our analysis indicates that all of the sequencing centers surveyed met the standards for 99.99 percent accuracy over the time period studied,” the researchers write in Nature.
They assessed sequences from three large-scale sequencing centers in the United States and four smaller centers in Japan, France, and the United States.
Each sequencing center had its own system for removing errors in the sequence, and some exceeded standards.
“The nature of the Human Genome Project as a pilot project for large-scale genomic sequencing makes it difficult to describe the quality of the human genome sequence as a singular entity,” the authors write. They note that “caution should be exercised in extrapolating” their data beyond the specific regions of the genome surveyed in the study.
The scientists also recommend a centralized quality-control system for future large genome sequencing projects that would help researchers better troubleshoot problems as they arise during the final stages of the work.