The report for rs1079610 shows an assay sample size of 65, whereas one of the ss reports for this cluster shows a 2N sample size of 1476. Why are the sample sizes different?
There are two sample-size fields in dbSNP. One field is called the SNP Assay sample size; it reports the number of chromosomes in the sample used to initially ascertain or discover the variation. The other sample-size field is called SNPPOPUSE or population sample size; it reports the number of chromosomes used as the denominator in computing estimates of allele frequencies by dbSNP submitters. These two measures need not be the same. In this case, the assay sample size for the refSNP is simply the addition of the sample sizes for each member ss. In this case: 48 (from YUSUKE) + 10 (from TSC) + 3 (from SC_JCM) + 2 (from SC_SNP) + 2 (from SSAHASNP) = 65. If multiple ss from the same submitter are in the same cluster, dbSNP counts the sample size only once for each submitter. The population sample size of 1476 is the sample size reported with the population frequency data in ss4926339, reported by YUSUKE.
