Archive | August 2013

Areas of faster and slower mutations in our chromosomes

A team of Penn State researchers has made a map of human chromosomes that shows the areas where mutations are more and less frequent; in their words “mutationally hot and cold regions.” However I found their diagram extremely difficult to understand. It took me quite a while to figure out the areas that are hot and cold for the SNPs that genetic genealogists are interested in. So I redid their image, removing the color for microsatellite repeat alterations, and changed the colors a little to be more in tune with hot and cold for me.

Here is my version:



Gray presumably are the areas not done and white outlined with black shows the centromeres. The one place with the least mutation is the X chromosome.


No guarantees that my reinterpretation of the graph by Kateryna Makova and Francesca Chiaromonte is correct!

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First version of the DNA Segment Mapper is Released

So many people were trying to use my DNA chromosome mapper tool to look at a picture of their DNA relatives’ matching segments that I realized that another tool was needed to meet that demand. The first version of the new DNA segment mapping tool is ready. More information is at

Sample Output from the DNA Segment Mapper

Sample Output from the DNA Segment Mapper


The DNA Segment mapper can show the matching DNA from up to 40 people in a chromosome style chart. Here is what my Dad’s top 40 matches look like (names are removed). The first two are first and third cousins once removed.

There is a page under tools above with more complete description and documentation.

Results in from my Double 3rd Cousin!!

According to family lore, when their business needed money my great-grandmother Charlotte Langermann Thannhauser, on my German Jewish side,  fixed up her sister Lina with her husband’s half brother in order to get Lina’s dowry invested in the family enterprise. Not such an uncommon occurrance. I was able to convince Lina’s great-granddaughter on the straight maternal line to test at 23andme. She is almost doubly my third cousin, sharing DNA from the Thannhauser and Langermann lines but not Engel.Dbl3rdCousin

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Chromosome Mapping Tool Released

The DNA segment chromosome mapping tool is now released for all to try. This is the current URL:

and the documentation is here:

Thanks to all the testers, I think the bugs have been found and fixed. The next release will have some enhancements so make your suggestions here. So far I expect to add the following features:

  • ignore the side column so alternately chose a side and color
  • better error reporting and more bullet proof
  • add a third option and thus line on the chromosomes for unknown or both
  • add a note column that is part of what appears on mouse over with the MRCA
  • allow selection of colors
  • make a version designed to show overlaps on unknown relatives

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