PRKCA and myeloid sarcoma: To capture most of the genetic variation of the PRKCA gene implicated as a primary positional candidate by the initial SNP-based analysis, and to potentially identify allelic variant(s) predisposing to MS, 211 SNPs mapping to the PRKCA gene and the 1-Mb flanking regions (see Materials and Methods for details) were selected from the dbSNP database (http://www.ncbi.nlm.nih.gov/projects/SNP) to evenly cover the region, and genotyped using a BeadArray platform in 211 Finnish MS families (Table 1, Study sets I + II).