Currently, molecular diagnostic tests are available for AD. With regard to PSEN1 (AD3), it is possible to perform mutation analysis, sequence analysis, and mutation scanning on a clinical basis. For identification of a PSEN1 mutation, a history of early-onset AD and another family member (principally a first-degree relative) also with early-onset AD is relevant.
The PSEN2 gene is well characterized, but only nine mutations have been found; most of them are point mutations in the coding region, causing an amino acid change. On one of these mutations (a substitution of an isoleucine for an asparagine at codon 141), the DNA sequence change (AAC vs. ATC) creates a Sau 3a restriction enzyme cleavage site, whose mutation is easy to detect. For PSEN2, sequence analysis and mutation scanning are available on a clinical basis.
Forty-three families with 16 APP (AD1) mutations have been defined. It is probable that because of the limited number of affected individuals, the molecular genetic testing is available only on a research basis by direct DNA study.
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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.