Category Archives: Genetics

New Research on the Role of MECP2

flaskResearch newly published in PNAS, Proceedings of the National Academy of Sciences, helps to clarify how the MeCP2 protein regulates genes, and may help provide an explanation of the role of MECP2-related disorders in autism. Researchers at Harvard University and the Washington University School of Medicine published their findings showing that MeCP2 plays a particular role in regulating very long genes in the brain. They found that MeCP2 reduced the activity of genes in proportion to the number of available sites for methylation. Therefore, the longer the gene, the greater the role of MECP2 in regulating the gene, and thus the very long genes in the brain are most sensitive to changes in levels of MeCP2.

Previous research has suggested that the function of very long genes in the brain may be a common denominator in at least many of the underlying causes  of autism. This new finding may suggest that both the underactivity of the MECP2 gene found in Rett syndrome and overactivity of the MECP2 gene found in MECP2 duplication syndrome may result in impaired responsiveness of these very long genes, potentially producing symptoms of autism. Continue reading

Touch, Autism, and MECP2

flaskResearchers 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

MeCP2 and the adult brain

mouseA 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

Another Big Step Forward with CRISPR

NEW3“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

MECP2: A Big but Somewhat Blurry Picture

QuestionMarkOPINION: 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

Rats, Mice, MECP2 Differences and Implications

mouseOn 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

More thoughts on undiagnosed cases

CAUTION2One 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

MECP2 Duplication is Not So Rare as Once Thought

NEW3Although 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

Syndromes, Clinical Syndromes, Genetic Syndromes, and Associations

CAUTION2The term syndrome gets used a lot by healthcare professionals and by the public in general. Most people have a fairly good idea of what it means, but it may be helpful to look a little closer. Syndrome comes from a Greek word meaning concurrence, things that are commonly found together. So, syndrome is generally used to refer to a group or pattern of symptoms that typically go together.  That much is pretty straight forward. Sometimes, however, syndrome has a narrower, more specific meaning. Continue reading

Chromosome Disorder Awareness Week ( 7 – 13 th June 2015 )

Unique

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.