Overlapping DNA Segments
| cM |
Matching on Chromosome 1 |
|
Match 1 |
|
Match 2 |
|
Non-Match |
|
|
| 20.5 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 7.6 |
|
|
|
|
|
|
|
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|
|
|
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|
No. Part of a matching DNA segment may have a higher or lower centiMorgan (cM) value than the segment’s average. One of your matches will then have a much higher cM value for their segment.
cM Values For Three SNP Sets
| SNP Set |
cM |
SNPs |
Chromosome |
Start Location |
Stop Location |
| 221 |
0.48 |
100 |
1 |
82521165 |
82870559 |
| 222 |
0.26 |
100 |
1 |
82871547 |
83219651 |
| 223 |
0.48 |
100 |
1 |
83221230 |
83764336 |
This is because the recombination rate across the human autosomal genome is highly variable. For example, one matching SNP set might be 349,394 bp (base pairs) long and .48 cM while the one next to it is about the same length but is only .26 cM.
