There’s an intriguing paper in today’s issue of Nature. Sergio E. Baranzini and colleagues looked at three pairs of identical twins, two female pairs and one male pair, in which one twin is healthy and the other has the autoimmune disease multiple sclerosis. The researchers conducted the most detailed genetic analysis of monozygotic twin pairs to date.
For one of the female pairs, the team sequenced each twin’s entire genome. For all three pairs they sequenced the messenger RNAs being produced by each individual’s CD4+ T cells (immune system cells known to play a role in multiple sclerosis). And for all three pairs they looked at the epigenetic programming of genes in the CD4+ cells.
The researchers were looking for subtle genetic differences between the twins in each pair that might explain why one got MS and the other didn’t. They did find a few subtle differenes, but none that were consistent across all three pairs.
In other words, they found nothing interesting.
Which is interesting.
Baranzani, S.E., J.M. Mudge, et al. 2010. Genome, epigenome and RNA sequences of monozygotic twins discordant for multiple sclerosis. Nature 464: 1351-1356.