Structure of the α2 gene surrounding the 807 and 873 polymorphisms. Three α2 gene alleles, defined by eight nucleotide polymorphisms, are indicated in the figure. Exons 6 through 9 are shown in boxes; positions of the exons in the cDNA sequence and the length of each exon are indicated beneath each exon box. The polymorphisms at bp 807, 837, and 873 are shown in bold. The Br polymorphism at bp 1648 is also shown in bold to the right. Introns F, G, and H are indicated. The length of each intron is shown in parentheses. The frequency (f) of each allele was determined from a random pool of 85 individuals. cDNA and intron positions of the polymorphisms are indicated. The ability of each allele to be cleaved by Nde I or Bgl II (+ or −) is indicated in tabular form next to each allele. The precise bp differences that change susceptibility to cleavage by Nde I or Bgl II within intron G are indicated.
