Detection of the FcγRIIA K 127 mutation. (A) SSCP analysis of the FcγRIIA PCR product from genomic DNA is shown. In lane 4, a unique SSCP pattern (arrowheads, top band) is seen in comparison with H/R¹³¹ (lanes 1 through 3), R/R¹³¹ (lanes 5 and 6), and H/H¹³¹ (lanes 7 and 8) samples. (B) DNA sequence analysis of the PCR product with the unique SSCP pattern shows heterozygosity for C (blue) and A (green) at the first nucleotide of codon 127. The sequence also indicates R/R¹³¹ homozygosity (G, black, at the second nucleotide of codon 131).