Fragile X Syndrome and Fragile Sites

Fragile X syndrome is a relatively common, yet—until recently—poorly understood inherited condition characterized by variable degrees of learning and social disability. First discovered in 1943 (when it was known as the Martin-Bell syndrome), it derives its name from its frequent association with a rare folate-sensitive fragile site (FRAXA) localized near the distal tip of the long arm of the X chromosome (Fig. 1) at Xq27.3, later also confirmed as the site of the gene locus.[1] In fact, there are two distinct conditions associated with expressed site fragility in this chromosomal segment: the FRAXE site is difficult to distinguish from FRAXA by conventional cytogenetics, but high-resolution methods map it slightly distal at Xq28. Some, but not all, properties of the FRAXA locus also apply to FRAXE; the primary discussion in this article will be of FRAXA, but the distinctive characteristics of the FRAXE locus will be pointed out wherever relevant.

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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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