Figure 4. Direct sequencing of exon 13 of the TGFBI gene in the proband of Family Three (individual I-1). The DNA sequence around the codon for histidine 572 (CAC) of the TGFBI gene is presented. The sequence shows a heterozygous, single-base A→G transition at nucleotide 1762, resulting in the replacement of histidine (CAC) with arginine (CGC) (H572R). The codon numbers and the amino acid sequence are indicated at the top of the figure.