Investigation of the eotaxin gene -426C-->T, -384A-->G and 67G-->a single-nucleotide polymorphisms and atopic dermatitis in Italian children using family-based association methods.

BACKGROUND: Eotaxin plays an important role in atopic dermatitis (AD) as a potent chemoattractant and activator of eosinophils and T-helper 2 lymphocytes. AIM: To investigate whether single-nucleotide polymorphisms of the eotaxin gene are associated with AD, we investigated the genotype and allelic frequencies of -426C-->T, -384A-->G, and 67G-->A SNPs in 130 Italian families. METHODS: In total, 130 children with either the extrinsic allergic or intrinsic nonallergic forms of AD (EAD and IAD) were recruited from 130 families. Genotyping was performed using PCR and restriction fragment length polymorphism analysis. RESULTS: A significant difference was observed in the genotype frequency of the -426C-->T SNP between children with EAD and those with IAD (P = 0.01), and between children with EAD and controls (P = 0.01). The allele frequencies of the -426C-->T SNP were significantly different between children with EAD and those with IAD (P < 0.01), and between children with EAD and controls (P < 0.01). For children with EAD, the genotype frequency of the -426C-->T SNP was no different between the groups with mild, moderate and severe SCORAD (P = NS). No significant association was observed between the -384A-->G and 67G-->A SNPs and the two groups of children with EAD and IAD compared with the control group. In 32 trios selected from 68 EAD families, the transmission disequilibrium test showed a preferential transmission of the -426T allele from the parents to affected offspring (P < 0.01). CONCLUSIONS: Our results suggest that in our group of children with AD, the eotaxin gene may play a crucial role in the development of extrinsic AD, probably with other genetic factors.