Molecular Screening Of The Lqts Genes

The primary consequence of the large heterogeneity of LQTS is that the vast majority of probands have their own ''private mutation'' with no or few hot spots so far identified. Therefore, the molecular screening of the entire ORF on the known gene is the only available option. In order to complete the analysis, 16 exons of KCNQ1, 15 exons of KCNH2, 28 exons of SCN5A, and 2 exons of KCNE1 and KCNE2 must be completely screened. ANK2 encompasses 46 exons, but a routine analysis did not indicate that the only LQT4 family so far reported has a very peculiar phenotype (see above).

A fast and standardized screening methodology is still not available. Denaturating high-pressure liquid chromatography (DHPLC) and DNA sequencing are the most widely used techniques among laboratories offering LQTS genotyping.

Nonetheless, the number of cardiologist and geneticists requesting the screening is increasing and it is therefore important to make few relevant statements concerning implications and value of genetic screening. The major implication of finding the molecular alteration in LQTS lies in the possibility to obtain information that adds to the phenotypic assessment. This is true especially for LQT1, LQT2, and LQT3 genetic variants where a genotype-based clinical management is progressively entering the clinical practice.

When the genetic defect is identified in a proband, genetic screening could be made available to family members. In this step, genetic testing moves from being a method that confirms and refines a known diagnosis to being a diagnostic technique may be applied to healthy individuals (nonpenetrant carriers). Learning to be a ''gene carrier'' may expose asymptomatic individuals without clinical phenotype of the disease to the evidence that they carry and may transmit a potentially fatal disease. Counseling these patients is very difficult. It is recommended that before undergoing genetic testing these individuals are informed about the implication of a positive result.

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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