Compare SNP frequency of patient cohort to DBSNP and test for significance

Question

[zeynk]

Hi,

I have analyzed the sequencing data of a patient cohort and found some SNPs that occur in a number for patients. How can I calculate, if the SNP occurence is significantly elevated in my patient cohort?

For instance, one SNP is present in about 40% of the patients, while the minor allele frequency of that SNP in dbSNP is around 3%. Seems significant to me, but how can I calculate a statistics?

I was thinking of treating the dbSNP data as a separate patient cohort and compare the two cohorts, for instance with a t-test, however I do not know the number of individuals in dbSNP and also could not find this number on their page...

Thanks, zeyn