Severity of hemophilic arthropathy in relation to HFE mutations. Number of episodes of hemarthrosis/year (A) and number of affected joints (B) according to clinical severity of hemophilia. Individual patients in each group are represented according to the presence of HFE mutations: C282Y heterozygous (), H63D carriers (○), compound heterozygote (•), and wild-type (WT) patients (). Four patients were excluded: 2 with severe hemophilia (one doing prophylactic treatment at the time of the study and another with no clinical data available); 1 patient with moderate hemophilia without complete relevant clinical information; and 1 patient with mild disease doing immunotolerance treatment at the time of the study. The dotted lines represent the cutoff values established for hemarthrosis/year (> 6) as an indication of severity of the arthropathy. The cutoff for number of joints affected was arbitrarily established for this study (> 3).