AIM: To study the association between Crohn’s disease (CD), Mycobacterium avium subspecies paratubercu- losis (MAP), and genetic factors by examining the role of natural resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms (now SLC11A1) in Sar dinian patients with CD and controls. METHODS: Thirty-seven CD patients and 34 controls with no inflammatory bowel disease (IBD) were recruited at the University of Sassari after giving written con sent. Six SCL11A1 polymorphisms previously reported to be the most significantly associated with IBD were searched. M. paratuberculosis was identified by IS900 PCR and sequencing. Logistic regression was used to cal culate odds ratios (OR) for the associations among CD presence of MAP, and 6 loci described above. RESULTS: For the first time, a strong association was observed between polymorphisms at NRAMP1 locus 823C/T and CD. While CD was strongly associated withboth NRAMP1 and MAP, NRAMP1 polymorphisms and MAP themselves were not correlated. CONCLUSION: Combined with previous work on the NOD2/CARD15 gene, it is clear that the interplay of ge- netic, infectious, and immunologic factors in the etiology of CD is complex. AIM: To study the association between Crohn’s disease (CD), Mycobacterium avium subspecies paratubercu- losis (MAP), and genetic factors by examining the role of natural resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms (now SLC11A1) in Sar dinian METHODS with Thirty-seven CD patients and 34 controls with no inflammatory bowel disease (IBD) were recruited at the University of Sassari after giving written con sent. Six SCL11A1 polymorphisms previously reported to be the most significantly associated with IBD were searched. M. paratuberculosis was identified by IS900 PCR and sequencing. Logistic regression was used to cal culate odds ratios (OR) for the associations among CD presence of MAP, and 6 loci described above. RESULTS: For the first time, a strong association was observed between polymorphisms at NRAMP1 locus 823C / T and CD. While CD was strongly associated withboth NRAMP1 and MAP, NRAMP1 polymorphisms and MAP individuals were not correlated. CONCLUSION: Combined with previous work on the NOD2 / CARD15 gene, it is clear that the interplay of ge netic, infectious, and immunologic factors in the etiology of CD is complex.