Fig. 1. Representation of DNA sequencing electropherograms. Each peak represents a DNA nucleotide. Double peaks show heterozygous alleles. ( A ) Sequence region of a silent variant (mutation T305AG), which leads to a shift of the reading frame. ( B ) Sequence region of mutation G1294T. A vertical bar indicates the position of the mutation. The top row represents sequences of patient number 2, the middle row represents those of his sister, and the bottom row represents sequences of a control (wild-type) person.