SNP haplotype

Drysdale s recent study, the first of its kind, assessed the effect of combinations of SNPs (haplotypes) on response to the drug, albuterol (146). Variation in 13 SNPs could be organized into 12 haplotypes, and investigation of these haplotypes in several discrete populations (Caucasian, African-American, Asian, and Hispanic-Latino) revealed >20-fold differences among the frequencies of the four major haplotypes. Mean responses to bronchodilator therapy with albuterol of individuals with the five most common (FAR haplotypes varied by greater than twofold, but were unrelated to individual SNPs. 

Further investigations are needed to characterize the effect of variants (SNPs, haplotypes) on CYP1A2 activity. 

It has been demonstrated that 25% of dose variability could be explained by the patient s VKORCl SNP haplotype, which shows a strong correlation with their warfarin dosage requirement (low-, intermediate-, and high-dose)... 

The combinahon of allele-specific PCR with primer extension and MALDI-TOF-MS for haplotyping may help to overcome some of the throughput hurdles of current technologies. MALDI-TOF-MS offers multiplex SNP haplotyping capabilities while maintaining a high analysis speed and accuracy. 

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