The first family’s genome has been sequenced (no, not THAT first family). A family of four (mom, dad and their two children) had their entire genomes sequenced and the results are now out in the online edition of Science. This particular family was chosen because their children both have two very, and I mean very, rare recessive genetic diseases: Miller syndrome and a lung disease called primary ciliary dyskinesia. Miller syndrome causes craniofacial abnormalities and is estimated to occur in about 1 in a million people while PCD is found about once in 10,000 people. These genome sequences, when compared to the sequence data from the human genome project has provided some clues about which genes are involved in these diseases —for example, they’ve narrowed down the causes of Miller syndrome to four candidate genes.
While this is clearly a breakthrough for understanding these rare genetic disorders, there was another interesting finding about mutations. Mutations are important because they can be good, bad or indifferent. Bad mutations, also called deleterious mutations, can be lethal or cause disease. Good mutations might make you into the Incredible Hulk… no, really, they can be good in that mutations are the fodder for variation in populations and for evolution. Mutations accumulate and slowly change organisms over looooong periods of time. But most of the time, we don’t even see the effects of mutations, these silent mutations don’t sound terribly interesting but they are actually very valuable tools for scientists.
First, these mutations tell us something about how quickly humans are evolving. Previous estimates were that every child received 75 mutations from each of their parents, but this study suggests that you might have only received a total of 60 mutations from both your parents combined. So, go and buy your folks a nice mothers/fathers’ day present this year, m’kay?
The rate that mutations accumulate are also used to estimate how distantly people, or groups of people, or people from other plants/animals etc. are related to one another, and how much time has passed since these people/groups/taxa shared a common ancestor.