A recent study identified the ADAM33 gene as a promising candidate contributing to asthma. In Puerto Rican and Mexican populations, we have genotyped six single nucleotide polymorphisms (SNPs) that were used in the Genetics of Asthma in Latino Americans Study. We chose to study these two populations because in the United States, Puerto Ricans have the highest asthma prevalence, morbidity, and mortality and Mexicans the lowest. We used the transmission disequilibrium test to analyze associations between the ADAM33 gene variants and asthma, asthma severity, bronchodilator responsiveness, and total IgE levels using single SNPs, two to six SNP combinations, and specific haplotypes in 583 trios (proband with asthma and both biological parents). We also genotyped matched control samples to allow case-control analyses. None of the transmission disequilibrium test or case-control results showed significant association in either population. We found no evidence for association of single SNPs with asthma severity, bronchodilator response, or IgE levels in Mexicans or in the combined population. Two SNPs showed a modest association in Puerto Ricans, insignificant when the number of comparisons was taken into account. We conclude that the ADAM33 gene is not an important risk factor for asthma or for asthma-associated phenotypes in Mexicans or in Puerto Ricans.

Here we report a large, extensively characterized set of single-nucleotide polymorphisms (SNPs) covering the human genome. We determined the allele frequencies of 55,018 SNPs in African Americans, Asians (Japanese-Chinese), and European Americans as part of The SNP Consortium's Allele Frequency Project. A subset of 8333 SNPs was also characterized in Koreans. Because these SNPs were ascertained in the same way, the data set is particularly useful for modeling. Our results document that much genetic variation is shared among populations. For autosomes, some 44% of these SNPs have a minor allele frequency ≥10% in each population, and the average allele frequency differences between populations with different continental origins are less than 19%. However, the *Corresponding authors. Jong-Eun Lee is to be contacted at fax: +82 2 364 4778. Michael T. Boyce-Jacino, fax: +1 609 818 0054. PuiYan Kwok,

Targeted resequencing of genomic DNA from organisms such as humans is an important tool enabling experimental access to variation within the species and between similar species. Taking full advantage of the reference genome sequences in designing robust, specific PCR assays and using stringent conditions, resequencing can be done efficiently without purification of the PCR product. By using a 10-fold greater amount of one primer when setting up the PCR initially in a new version of asymmetric PCR, one simply adds the rest of the sequencing reagents at the end of PCR and allows the sequencing reaction to proceed, with the excess PCR primer serving as the sequencing primer. We demonstrated that this streamlined protocol can be used with PCR products up to 1300 bp and had up to a 97% success rate in high-throughput analysis of allele frequencies for >30,000 single-nucleotide polymorphisms (SNPs). SNP primers and characterization results are provided athttp://snp.wustl.edu.