We genotyped 61 European American (36 males and 25 females, average age at diagnosis 36.0±17.5) and 56 African American (26 males and 30 females, average age at diagnosis 22.5±14.5) patients with idiopathic biopsy-proven FSGS and no family history of FSGS using the Illumina 1M-Duo platform. Patients were recruited in accordance with protocols approved by the relevant human research committees from medical centers in the eastern United States, mainly from New York city. We used 1641 unselected European American samples and 1827 unselected African American samples genotyped with the Illumina 550Kv3 platform from the iControldb database (http://www.illumina.com/science/icontroldb.ilmn). In brief, we downloaded all genotyping data available from genotyping studies that used the illumina 550Kv3 array using ‘European American’ (n= 1641) or ‘African American’ (n= 1827) as the selection criteria. These two datasets were then converted to plink format using scripts we developed (Ross Lazarus, unpublished). We matched cases and control datasets based on their ethnicity. After correction for ancestry, 110 European American controls and 68 African American controls were excluded on the basis of excessive ancestry which was neither European nor African.
