Cause and Laboratory Diagnosis

The condition is caused by mutations in the COL3A1 gene coding for the a1 chain of type III collagen. This homotrimer is a major structural component of skin, blood vessels, and hollow organs. The diagnosis of vascular EDS is based on compatible clinical findings and confirmed by biochemical testing. Biochemical testing includes analysis by SDS-PAGE of radioactively labeled collagens from skin fibroblast cultures. This is a highly sensitive investigation and probably identifies more than 95% of individuals with structural alterations in the proteins synthesized. It allows one to detect quantitative (reduced amounts of collagen type III) or qualitative (mutant collagen type III with altered electro-phoretic mobility) abnormalities of type III collagen. For example, substitution of a glycine residue by a bulkier amino acid destabilizes the helix and delays its formation, causing excessive posttranslational modification and hence an altered electrophoretic pattern. Molecular genetic testing to identify mutations in the COL3A1 gene is available to patients with a biochemically confirmed diagnosis of vascular EDS. To date, more than 250 COL3A1 mutations have been identified. These include point mutations leading to substitutions for glycine in the triple-helical region of the collagen molecule, splice site mutations resulting in exon skips, intron inclusion or complex and multiple outcomes, partial gene deletions, and, less commonly, mutations resulting in haploinsuffi-ciency.[14] Vascular EDS is an autosomal dominant disorder, but parental somatic mosaicism for COL3A1 mutations has been documented.

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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