Segregation of wild-type

I, Iⁱ¹, andIⁱ² alleles in 2 adult i pedigrees. Pedigree drawings (upper) and PCR-SSP-RFLP analysis of the family members (lower) of pedigree S (A) and pedigree W (B). Pedigree drawing: To avoid confusing the blood group I phenotype and the I gene, the standard symbols for generations I, II, and III, are not used. Open and solid symbols for male (square) and female (circle) denote an person with common I and adult i phenotypes, respectively. I locus genotypes under each symbol are inferred from the results of PCR-SSP-RFLP analysis for each person. The adult i propositus in each pedigree is indicated by an arrow. Samples from S-1 and S-3 were unavailable in the current study to determine their I genotype; however, these persons were previously demonstrated to have I phenotype.27 PCR-SSP-RFLP analysis: w and m represent the PCR amplifications using the wild-type primer set and mutant primer set, respectively, for distinguishing theI and Iⁱ¹ alleles (described in “Materials and methods” and “Results”). The 218-bp PCR products were then digested with BstUI restriction endonuclease for distinguishing the I andIⁱ² alleles. Plasmid clones bearingI, Iⁱ¹, andIⁱ² cDNA segments served as control templates. The results for the third generation of pedigree S, S-9 to S-12, are not shown. Lane M shows the molecular mass standards of the 100-bp ladder.