Systemic lupus erythematosus risk alleles in Central and Southern European patients and controls. Distribution of the number of systemic lupus erythematosus (SLE) risk alleles in Central European and Southern European SLE patients and controls. y axis, percentage of subjects in each of the four strata with the corresponding total number of SLE risk alleles. Distance-weighted least-squares fitting lines are presented. White bars and dotted line, Southern European controls; light grey bars and short-slashed line, Central European controls; medium grey bars and long-slashed line, Southern European SLE patients; dark grey bars and continuous line, Central European SLE patients.