HLA-DRB1 and systemic sclerosis: No deviation from Hardy-Weinberg equilibrium was detected in the controls (DRB1: P = 0.4327, DQB1: P = 0.2136, DPB1: P = 0.7464, all locus: P = 0.5000), though a deviation was observed in the overall SSc patients (DRB1: P = 0.1017, DQB1: P = 0.0769, DPB1: P = 0.0260, all locus: P = 0.0093).