Association of NOD1 polymorphisms with atopic eczema and related phenotypes

BACKGROUND: Interactions with microbial pathogens are crucial for the maturation of the immune system. The nucleotide-binding oligomerization domain protein 1 (NOD1) is a cytosolic receptor sensing a muropeptide found mostly in gram-negative bacterial peptidoglycans. NOD1 is located on chromosome 7p14-p15, a region that has been linked with atopy. Recently, polymorphisms of the closely related NOD2 have been associated with atopy-related traits. OBJECTIVES: Within a large population-based cohort of German adults (n = 1417), a case-control population for atopic eczema (n = 454), and a large cohort of parent-offspring trios for atopic eczema (189 trios), we evaluated 11 NOD1 polymorphisms for associations with atopic phenotypes. Methods Subjects were phenotyped by standardized questionnaires and interviews, skin examination, and serum IgE measurements. Genotyping was performed by using matrix-assisted laser desorption ionization-time of flight mass spectrometry. RESULTS: Analyses revealed significant association of one NOD1 haplotype with atopic eczema in the population-based cohort ( P = .004) and the case-control population ( P = .003). Another NOD1 haplotype was associated with decreased total IgE ( P = .008). In addition, significant associations with total serum IgE levels were observed for polymorphisms rs2907748 ( P = .006), rs2907749 ( P = .012), and rs2075822 ( P = .018). These polymorphisms were significantly associated with atopic eczema and asthma in the family-based association analyses ( P = .001-.043). Seven polymorphisms showed significant transmission distortion for total IgE levels ( P values < .0001-.029). CONCLUSION: These data indicate that genetic variants within NOD1 are important determinants of atopy susceptibility.