Researchers at Harvard University are suggesting a new theory of autism. They are raising the possibility that atypical neurological responses to touch can play an important role in developing symptoms of autism, and suggesting that abnormal levels of MeCP2 levels in cells that respond to touch can be critical to the development of symptoms of autism.
Experiments with a number of types of genetically engineered laboratory mice, they found autistic-like behavior developed in those without MECP2 activity in touch cells, but not if normal activity was present in touch cells but not in other cells in the body. There are a number of cautions in interpreting this finding and the associated theory, but there are also a number of general observations that make this theory enticing. Continue reading
A recent study looks at the effects of the MeCP2 protein levels on adult brains. Although this study looked at blocking MeCP2 [similar to Rett syndrome and the opposite of MECP2 duplication syndrome], the fact that it showed different kinds of responses depending on the developmental maturity of the lab mice, suggests that the most critical role of the MeCP2 protein may be in the function of the adult brain.
This finding is consistent with Continue reading
“Using a previously undescribed approach involving single guide RNA, we successfully removed large genome rearrangement in primary cells of an individual with an X chromosome duplication including MECP2.”
Wojtal, D., Kemaladewi, D. U., Malam, Z., Abdullah, S., Wong, T. W., Hyatt, E., et al. (2016). Spell Checking Nature: Versatility of CRISPR/Cas9 for Developing Treatments for Inherited Disorders. American Journal of Human Genetics, 98(1), 90-101.
2015 and 2016 have already been marked by some major breakthroughs in potential steps toward treatment of MECP2 Duplication Syndrome. This report in the American Journal of Human Genetics definitely adds to collection. Continue reading
OPINION: This week Nature published a very interesting and possibly groundbreaking study on schizophrenia. It doesn’t mention MECP2 but it does talk about the role of the pruning process in the brain. The way our brains develop is by creating a bunch of new connections and then trimming away the ones that are not needed or helpful. The article suggests that schizophrenia develops when the pruning process goes too far in some parts of the brain. This is also consistent in some earlier reports that did suggest that certain defects in MECP2 were implicated in early onset schizophrenia.
Too much or too little MeCP2 activity has also been connected to a number of other conditions, such as Continue reading
On first reading, differences between mice and rats in responses to missing aMECP2 gene didn’t seem to relevant to research on treating extra MECP2 gene activity in humans with MECP2 Duplication Syndrome. Later, it suddenly hit me that this could be very relevant and important. This research suggests that rats may be a better model for studying MECP2 Gene activity than mice that are currently being used in most of the studies. In a more general sense it also suggests that the role of the MECP2 gene may be species specific. Continue reading
One of the facts that suggests that it is likely that there are still many more undiagnosed cases of MECP2 Duplication Syndrome than there are diagnosed cases is that geographic, political, and socio-economic factors appear to play important factors in incidence. While some conditions and syndromes are more common in certain gene pools, there is no evidence so far that MECP2 Duplication Syndrome discriminates on the basis of race, geography, or family income. Continue reading
Although MECP2 Duplication Syndrome (or Xq28 Duplication) is correctly identified as a rare condition, available research suggests that it is not as rare as we once thought. For example, Japanese researchers published a 2014 study in Human Genome Variation that described from results of 1,250 patients with intellectual disabilities who had not received specific diagnoses. The researchers performed advance genetic testing on these 1,250 patients and found probable genetic causes for 17% of these individuals. Many different genetic conditions were found among these 17% of patients. However, one condition was found more frequently than any other. That condition was Xq28 duplication with duplication of the MECP2 gene. This suggests that MECP2 Duplication Syndrome is not nearly as rare as once believed and that many cases continue to go diagnosed.
In the words of the researchers: Continue reading
As strange as it may seem rare chromosomal disorders are quite common.
Sunday, June 7th, starts Chromosome Disorder Awareness Week. Unique is an international organization that raises awareness of chromosome disorders and their Awareness week kicks off 7 June 2015. For more information, check out their press release.
I usually don’t use this blog to comment on research that is primarily oriented toward Rett syndrome. Others with more expertise related to Rett syndrome can do a much better job of that. A recent article on Rett syndrome mice, however, deserves a bit of comment here because of its possible implications for MECP2 duplication syndrome. In “Methyl-CpG Binding Protein 2 Regulates Microglia and Macrophage Gene Expression in Response to Inflammatory Stimuli,” Cronk and colleagues raise the question of whether the role of the MECP2 gene in regulating the immune system could be central to most or all of the other problems seen in Rett syndrome. This possibility has been raised before both with Rett syndrome and MECP2 duplication syndrome, and this research provides some additional reason to take this hypothesis seriously. Continue reading