Collaborating institutions, including the Institute for Systems Biology (ISB), Complete Genomics, the University of Washington, and the University of Utah, have sequenced and analyzed the first whole genomes of a human family of four. The authors said that the benefits of sequencing an entire family include lowering DNA sequencing error rates, identifying rare genetic variants, and identifying disease-linked genes. "We were very pleased and a little surprised at how much additional information can come from examining the full genomes of the same family," said Dr. David Galas, co-corresponding author on the article and senior vice president at ISB. "Comparing the sequences of unrelated individuals is useful, but for a family the results are more accurate. We can now see all the genetic variations, including rare ones, and can construct the inheritance of every piece of the chromosomes, which is critical to understanding the traits important to health and disease. The continuing decline in the difficulty and cost of sequencing now enables us to use these new strategies for deriving genetic information that was too difficult or expensive to access in the past.” A particular family of four with two children with extremely rare genetic diseases turned out to be ideal for the study. Although the parents had no genetic abnormalities, they each carried recessive genes that resulted in their son and daughter being born with two extremely rare conditions--Miller's syndrome and primary ciliary dyskinesia (PCD). Miller's syndrome, a disorder characterized by facial and limb malformations, is thought to occur in perhaps one in one million people and has been diagnosed in only two families in the world, along with a few sporadic other cases.
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