Genetic Polymorphism

The human BChE gene is located on chromosome 3q26. The genomic region for BChE spans about 70 kb and has four exons and three large introns.[6] Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), PCR-restriction fragment length polymorphism (PCR-RFLP), and competitive oligo-priming-PCR (COP-PCR) were used to detect the common variants of the BChE gene.[7,8] For rare mutations, sequencing the PCR products is necessary. Usually, a DNA sample is extracted from peripheral blood, and exons 2, 3, and 4, which encode the mature protein of the BChE gene (Genbank Accession Number: J02879), are individually amplified by the PCR method. A total of 35 cycles of amplification are performed, each round consisting of a denaturation step at 94C for 1 min, an annealing step at 55C for 1 min, and an extension step at 72C for 1.5 min. After the sizes and homogeneity of the PCR products are confirmed by agarose gels stained with ethidium bromide, direct sequencing is performed using a dye terminator cycle sequencing core kit and a DNA sequencer.[9,10] The primers used for PCR and sequence are listed in Table 1.

Two genetic polymorphisms in the noncoding region of BChE were found early in 1990. At nucleotide — 116, the frequency of G is 0.92 and that of A is 0.08. At nucleotide 1914, the frequency of A is 0.74 and that of G is 0.26.[11] These frequencies are considered to have no effect on BChE activity. At least 49 mutations have been reported that are associated with low serum BChE activity, including 15 truncating and 34 nontruncating mutations (Fig. 1). The genetic mutation related to the atypical phenotype is D70G. Two fluoride-resistant phenotypes

Table 1 Primer sequences used to amplify the butyrylcholinesterase gene

Primer

Nucleotide location

Sequence (5' to 3')

Amplified region

AP3'

Intron 1

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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