A: Pedigree, genotypes, and clinical characteristics of family A. The segregation of IVS7nt-6G>A mutation is shown. At the time of examination, individuals 1, 2, and 3 were taking insulin, and individual 5 was on sulfonylurea agent. An arrow indicates the index case. Closed, half-closed, and open symbols represent subjects with diabetes, impaired glucose tolerance, and normal glucose tolerance, respectively. The first line under the symbols is the identification number of the examined individual. The second line is the age at diabetes diagnosis for affected members, age at death for deceased members, and age at examination for others. The third line is the genotype at −6 bp in intron 7 of the gene. In the last line, the information about renal phenotype was provided where appropriate. The genotype in parentheses has been inferred for two deceased subjects. N, normal allele; m, mutant allele; R, presence of renal malformations. B: Pedigree, genotypes, and clinical characteristics of family B. The symbols and the data are the same as in A. The genotype applies to codon 271 of the gene. At the time of examination, individuals 3 and 6 were taking insulin.