New theory of Down Syndrome cause

We have always assumed that, since Down Syndrome occurs in people with an extra chromosome 21, the disorder should occur because there is too much of some protein coded for on that chromosome. A recent study suggests it may be due to little of a protein. It looks like what happens is a chunk of RNA gets over-expressed, which causes this protein* to be under-expressed.

In rats, they were able to increase the protein level by doing something to the RNA, but it couldn't fix damage that had already occurred. I predict in a few years we will have an in utero treatment after an early blood test for Down.

Of course, this doesn't mean that none of the characteristics of Down Syndrome are caused by over-production of some proteins, just that the under-production of one is involved. No doubt researchers will be busily looking at it all.

*MeCP2, if you must know. It's a transcription factor. 

A gene for one aspect of Down's syndrome

Down's syndrome is caused by having an extra chromosome 21. Presumably, having the extra copy increases the production of some protein or proteins, which produce the observable effects. A researcher has found that superexpression of a particular gene that affects transmission between neurons may be the reason for the visual-spatial memory problems of people with Down's syndrome.

It is believed that the root of this problem is in the central part of the brain; more concretely, in the transmission between the hippocampus and a specific part of the brain. It would seem that cholinergic neurons, which should guarantee this transmission, undergo alterations in those persons with Down's syndrome, besides deteriorating with age. 

Since chromosome 21 has lots of genes on it to be overexpressed, lots of genes are likely to be related to Down's syndrome, but it's cool each time they find something, and this seems to be a big one.

Every time I hear about researchers finding a relation between some gene and some dysfunction, I imagine gene therapy for it in 10 or 20 years. We're learning so much about so many things.