Science-- there's something for everyone

Saturday, March 13, 2010

Sequencing family genomes

Hundreds of species, including Homo sapiens, have had their genomes sequenced, and more are being added to the list all the time. You can peruse a list of sequenced genomes here. In general, one or a few specimens of each species are used for genomic studies. Notoriously, John Craig Venter used his own DNA during his time at Celera Genomics.

David Galas and his team from the Institute for Systems Biology in Seattle have added a new twist by performing the first whole genome sequence of four members of a single family. The researchers sequenced the genes of both parents and two children within a single family. The siblings both suffer from a recessive genetic disorder known as Miller syndrome. After sequencing all four family members, the scientists were able to narrow down the list of possible genes responsible for this rare craniofacial disorder to just four. As more families have their genomes sequenced, associating disorders with specific mutations will be much easier.

In addition, by comparing the kids’ DNA to that of their parents, the geneticists found that the intergenerational mutation rate was actually about half the previously expected rate. This finding could have implications for estimates of genetic diversity and human dispersal rates.