ASRA on exon 3 of the GPIIIa gene from family members. (A) Genomic organization of the GPIIIa gene. The 15 exons are symbolized by vertical black bars, and the exon number is indicated; UTR refers to the untranslated region. The vertical arrow indicates the target sequence recognized by the Ava I restriction enzyme in the published sequence.19 The size of restriction fragments resulting from Ava I digestion of exon 3 for the La genotype is indicated (La⁺, mutated type; La⁻, wild-type). (B) A 10% polyacrylamide gel on which was loaded amplification products containing exon 3 of the gene for GPIIIa: nd, undigested amplification product from a normal donor, amplification products from L.M., L.J., C.M., and L.P. digested with the Ava I restriction enzyme. PM, pGEM DNA Markers (Promega). The size of each DNA fragment, in base pairs, is shown by horizontal arrows.