TraceHaplotyper

This program genotypes a tracefile that results from sequencing of two chromosomes, which one of them having a deletion preceding a SNP. In such case the phase of these markers can be determined.
Example Data Set
Source code

uploaded_file1 -> z3208_3012R.ab1
uploaded_file2 -> tra16R.exp
action -> phase

RESULTS

In the expected sequence the deletion is after base 200, indel size 8 bases.
SNP1 is at base 212, alleles A and G.
In the trace file the deletion site detected at position 219, score 640.6 (lower than 600 may indicate low trace file quality)
hence, to align the expected and the trace sequences a 19-base difference is accounted for.
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Analysis for SNP1, alleles A and G
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Finding the SNP1 allele that is located on the Ins chromosome
The expected pair of bases before the SNP site is G C
In the trace, the pairs of bases are:
221 base1 T base2 C
222 base1 C base2 G
223 base1 A base2 G are in the expected SNP site
224 base1 C base2 G
225 base1 A base2 T
The pair of bases that should precede the site of SNP on the Ins chromosome was located at 0 bases from the expected position
hence, the site of SNP for the Ins chromosome is at position 223 base1 A base2 G of these the expected base for the Del chromosome is G
Haplotype 1 is: Del, A
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Finding the SNP1 allele that is located on the Del chromosome
The expected pair of bases before the SNP site is G C
In the trace, the pairs of bases are:
229 base1 T base2 C
230 base1 G base2 C
231 base1 A base2 T are in the expected SNP site
232 base1 C base2 T
233 base1 G base2 A
The pair of bases that should precede the site of SNP on the Del chromosome was located at 0 bases from the expected position
hence, the site of SNP for the Del chromosome is at position 231 base1 A base2 T of these the expected base for the Ins chromosome is T
Haplotype 2 is: Ins, A
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View trace with ChromatogramApplet by Eugen Buehler

Eyal Seroussi Ph. D.

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