The existence of reciprocal microdeletion/microduplica-tion syndromes of 17p12 (HNPP/CMT) and 17p11.2 [SMS/dup(17)(p11.2p11.2) syndrome] suggests that other such reciprocal microduplication syndromes may exist but remain unrecognized. As more individuals are carefully checked for microduplications with more sophisticated techniques such as CGH arrays, the prevalence of such possible syndromes will become clear. It is particularly interesting to speculate for the DGS/VCFS region of 22q11, the site of the most common of the microdeletion syndromes with an incidence estimated at 1/4000 live births. The fact that a reciprocal 22q11 microduplication syndrome has so far gone unrecognized suggests that it is mild and highly variable. Considering the variability of the DGS/VCF deletion phenotype, which is currently recognized as at least three different syndromes, variability in the reciprocal duplications is highly likely. A mild and nondistinct phenotype is also suggested by the fact that the presence of the DGS/VCFS region on the CES chromosome does not appear to have an obvious effect on top of the CES phenotype. The one case reported to date with duplication of the DGS/VCFS region showed developmental delay and hypotonia, but the mother and grandmother with the same duplication appeared normal.[21]

Microduplications, like microdeletions, can shed light on developmental processes by revealing dosage-sensitive genes critical in developmental pathways. To this end, the genes in microduplication regions are being characterized and mouse models are being produced.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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