HP and synovial sarcoma: However, these are different from those of Olatunya et al. [38] in Nigeria, Khalid and Khalil [39] in Sudan, Moreira and Naoum [24] in Brazil, and Ostrowski et al. [23] in USA, where the most frequent Hp genotype in SS patients was Hp1-1 (43%, 68%, 36%, and 72%, respectively).