Modifications have been made for brevity and clarity. There are eight repeats of the tetranucleotide sequence.
The results presented in this paper reveal several interesting features of the stutter product that is produced in the amplification of tetranucleotide repeat sequences. Sequencing results of the vWA main allele bands and stutter bands indicate that the stutter band simply lacks one core repeat unit (TCTA) relative to the main band. A similar sequencing approach was also used in our laboratory to investigate the stutter bands in another tetranucleotide repeat locus, ACTBP2 (core repeat unit AAAG).