Segregation of wild-type I3,I3i1, and I3i3 alleles in an adult i pedigree.
(A) Pedigree drawings I, II, and III represent the first, second, and third generation, respectively, and the propositus is indicated by an arrow. Filled and half-filled symbols for male (square) and female (circle) denote a person with adult i and common I phenotypes, respectively. Open symbols with a cross represent the parents of the propositus; the samples could not be obtained because they had already died. The other open symbols denote persons with common I phenotype, but genotyping was not conducted. The genotype of the half-filled symbols is a heterozygote of wild-type I3 and mutated alleles, though genotypic analysis of individuals 2, 3, 4, 5, and 6 in III was not conducted. All adult i phenotypes were derived from heterozygotes of mutated I3i1 andI3i3 alleles. (B) Schematic diagrams of mutated alleles found in the adult i pedigree. I3 indicates the coding region of the wild-type IGnT3 presented in this study. ATG and TGA denote the enzyme's translation initiation and termination codons, respectively. Open circles represent nucleotide substitutions 1049G>A in the I3i1 allele, 1154G>A in the I3i2 allele, and 1006G>A in theI3i3 allele, respectively. The alleleI3i3 was found in the present study, whereas alleles I3i1 and I3i2have already been reported by Yu et al.14 These mutations in I3i1, I3i2, andI3i3 predict amino acid alterations of Gly350Glu, Arg385His, and Gly336Arg, respectively. Note that positions 1154 and 385 in allele I3i2 are based on theIGnT3 gene nucleotide and deduced amino acid sequences, respectively. The open square represents a possible nonfunctional missense mutation in the allele I3i3 exon 1 ofIGnT3.
