CCR3 and asthma: Three highly allelic single nucleotide polymorphisms were observed: –G/A substitution at position 190 of the CCR2 gene changes the amino acid at position 64 from isoleucine to valine of its protein, –T/C substitution at position 51 of the CCR3 gene results in a silent mutation at position 17 of its protein, and a 32 base pair deletion within the CCR5 gene clustered in chromosome 3p21.4 within a 300 kbp span were examined by the linkage disequilibrium and linkage analysis for asthma and atopy.