Down syndrome research

[3] Recent research has identified a region of the chromosome that contains the main genes responsible for the pathogenesis of Down syndrome,[4] located proximal to 21q22.3.

The elevated levels of DSCR1 and DYRK1A keep NFAT primarily located in the cytoplasm rather than in the nucleus, preventing NFATc from activating the transcription of target genes and thus the production of certain proteins (Epstein 583).

This disregulation was discovered by testing in transgenic mice that had segments of their chromosomes duplicated to simulate a human chromosome-21 trisomy (Arron et al. 597).

The mice squeezed a probe with a paw and displayed a 0.2 newton weaker grip (Arron et al. 596).

Testing by Olson and others in transgenic mice show the duplicated genes presumed to cause the phenotypes are not enough to cause the exact features.

While the mice had sections of multiple genes duplicated to approximate a human chromosome-21 triplication, they only showed slight craniofacial abnormalities (688–90).

Recent use of transgenic mice to study specific genes in the Down syndrome critical region has yielded some results.

Transgenic mice over-expressing ETS2 developed a smaller thymus and lymphocyte abnormalities, similar to features observed in Down syndrome.

Layer II of the entorhinal cortex and the subiculum, both critical for memory consolidation, are among the first affected by the damage.

Oxidative damage to neurons results in rapid brain aging similar to that of Alzheimer's disease.

The levels of 8-OHdG in the DNA of persons with DS measured in saliva were found to be significantly higher than in control groups.