We performed a genome-wide association analysis (GWA) of sporadic biopsy-confirmed FSGS subjects with either African or European ancestry using a dense set of more than one million single nucleotide polymorphisms (SNPs) included on the Illumina 1M-Duo array. We reasoned that common genetic factors may be high in magnitude of effect in cases, thus allowing us to use relatively small numbers of cases, matched for ethnicity, to a large control dataset. We used samples from the Illumina iControl (http://www.illumina.com/science/icontroldb.ilmn) database genotyped on the Illumina 550Kv3 array matched for ancestry to the cases.
