Genome Sequencing Becomes a Family Affair

A family of four has become the first to have their genomes sequenced for non-medical reasons. According to The Times, John and Judy West, both 53, and their children, Anne, 17, and Paul, 14, paid almost $200,000 to have their entire genetic code read by the sequencing company Illumina.

West was the CEO of Solexa, a sequencing start-up bought by Illumina in 2007. That company’s technology lies at the heart of Illumina’s popular sequencing instruments, which dominate the market. Last year, Illumina announced a personal genome sequencing service available for $48,000 with a doctor’s prescription. The company has already sequenced the genomes of actress Glenn Close and entrepreneur Hermann Hauser.

West told The Times,

“that he hoped that his family’s DNA data would benefit their health and advance research into genetic contributions to disease. He said that his children were “pretty smart” and had given enthusiastic consent: “They understand why some people might prefer not to know this sort of information.”

…His daughter Anne is using her own data at school to learn about genetics, and comparisons between the family’s genomes would be valuable to researchers investigating how DNA variations and mutations affect disease.”

The family’s unique endeavor has highlighted concerns over whether children can truly consent to having their genomes sequenced. Frances Flinter, a consultant in clinical genetics at Guy’s and St Thomas’ NHS Foundation Trust, London, told The Times: “I would be very cautious about this. Once you have sequenced someone’s genome, you can’t put that information back in the box.”

Blogger Daniel MacArthur writes,

I’ve personally got no ethical problem whatsoever with the Wests deciding to get their genomes sequenced. The medical benefits will likely be negligible, but then so are the potential harms (weighted by their probability), and a bright 14-year-old is more than capable of weighing these harms and giving informed consent.

There’s also a good scientific rationale for sequencing multiple family members: it improves the accuracy and interpretability of each individual’s sequence. This was ably demonstrated in a recent publication in which a family of four was sequenced by Complete Genomics in a hunt for a serious disease gene: that paper showed that combining data across multiple family members allowed analysts to dramatically improve the accuracy of sequencing.

The West’s aren’t the first family to have their genomes sequenced. Last month, Leroy Hood and colleagues at the Institute for Systems Biology sequenced a family of four in order to identify the genetic variations underlying a rare condition, called Miller syndrome, inherited by the two children. Technology Review covered the study:

By comparing the sequence of parents and offspring, researchers could calculate the rate of spontaneous mutations arising in the human genome from one generation to the next. The rate equates to about 30 mutations per child, lower than previous estimates.

One of the major problems with analyzing whole-genome data is isolating important genetic signals from noise–both sequencing errors and thousands of harmless genetic variations that have little or no impact on a person’s health. Comparing intergenerational genomes allowed scientists to filter out some of this noise. They honed in on the genetic changes that appeared from one generation to the next and then resequenced those regions to identify true changes. Hood estimates that errors are about 1,000 times more prevalent than true mutations. “In the future, when all of us have our genomes done, we’ll almost certainly have them done in families, because it increases the accuracy of the data,” says Hood.