FIGURE 2.

Restriction analysis to determine the frequency of haplotypes I and II of the hAT₁R gene. Because four polymorphisms in the hAT₁R promoter are in LD, the frequency of each haplotype may be calculated by measuring frequency of any polymorphism. Restriction enzyme HinfI digests the PCR-amplified fragment only when −680T is present. Therefore, genomic DNA from hypertensive patients and normotensive controls was amplified to produce 238-bp fragments as described under “Experimental Procedures.” The partial nucleotide sequence of the amplified fragment around the T/G polymorphic site at −680 of the AT₁R gene is shown in the first line. The HinfI restriction site (which will cleave the amplified DNA if nucleoside T is present at −680) is shown in the second line. The amplified DNA fragments were treated with HinfI and separated on a 3.5% agarose gel. Lanes 1 and 6, samples from TT homozygotes; lanes 2, 4, and 5, samples from GT heterozygotes; lane 3, sample from a GG homozygote; lane 7, positions of DNA markers.