Direct sequence analysis and SSCP profiles of amplified exons 4 of GP IIIa DNAs from the mother Duv, the father, and their child.

(A) The genomic DNA sequences corresponding to the region 512 to 522 of the GP IIIa cDNA are shown. The mother is homozygous for the C517 (underlined), and the father and the child are C/T heterozygous (Y). The C>T base change results in a Thr (ACC) for an Ile (ATC) substitution at the amino acid 140 of the mature GP IIIa. The polymorphic position is indicated by an arrow. (B) The interesting part of the SSCP profiles of the exon 4–PCR products obtained for the reverse DNA single strand at 20°C is shown. The peak detected at 230 minutes in the mother's profile corresponds to the C517 allele of the GP IIIa. The peak at 220 minutes obtained for the father and the child is specific for the T517 form. SSCP confirms the father and the child are heterozygous for the C>T mutation.