Published June 13, 2011
Rumor has it, Professor Xavier is accepting new recruits.
A breakthrough study has revealed that each one of us receives approximately 60 new mutations in our genome from our parents. Apparently, we’re all mutants.
The report is the first-ever direct measure of new mutations coming from mother and father allowing researchers to answer the question: how many new mutations does a child have and did he get them from mom or dad?
Although much of our variety results from the reshuffling of genes through sexual reproduction, “new mutations” are the ultimate source of new variations. “New mutations” are those that occur in the sperm or egg cells, mutations not seen in our parents.
Finding new mutations though, is extremely challenging given the event’s rarity – only 1 in every 100 million letters of DNA is altered each generation. As such, instead of directly measuring new mutations, previous studies often averaged mutation rates across both sexes or measured them over several generations.
“We human geneticists have theorized that mutation rates might be different between the sexes or between people,” explains Dr. Matt Hurles, Senior Group Leader at the Wellcome Trust Sanger Institute, who co-led the study with scientists at Montreal and Boston. “We know now that, in some families, most mutations might arise from the mother, in others will arise from the father.”
Professor Philip Awadalla, who also co-led the project and is at the University of Montreal explained: “Today, we have been able to test previous theories through new developments in experimental technologies and our analytical algorithms. This has allowed us to find these new mutations, which are like very small needles in a very large haystack.”
Hurles and Awadalla studied two families consisting of both parents and one child and came across some bizarre results. Remarkably, in one family 92 percent of the mutations came from the father, whereas in the other family, only 36 percent were from the father, a fascinating result that raises as many questions as it answers.
Equally remarkable – the number of mutations passed on from a parent to a child varied between parents by as much as tenfold.
Armed with their new technologies and algorithms, the team is now looking forward to studying more families as it looks to answer these riddles of the human genome.