Splice site pattern analysis and identification of similar sequences in the deep intron areas of human chromosome 21

We describe the results of an in silico experiment realized on the DNA sequence of human chromosome 21, with the aim of identifying splicing sites using a bioinformatics algorithm. The study was divided in two phases. In the first phase, we analyzed the branch site position and the characteristics of the pyrimidine tract. In the second phase, a search was conducted in the introns for sequences that are similar to splice sites using definition based on the result obtained in the previous phase. We found, in average, three similar sequences per intron. We also found that a number of splice sites have multiple branch point sequences.