From ISOGG Wiki
Multiple nulls in genetic genealogy
- Null25 Project
- The NULL448 Project
- Clan Colla 425 Null Project
These Projects focus on single alleles returning null values. This page is focusing on more than one null. Articles have been written that place the cause of multiples nulls on differences in the testing criteria of two companies. One example was that test results done at Ancestry were sent to Family Tree DNA for upgrades. Because the two testing companies use different algorythims nulls were the result. This could be one possible way they occurred. I had my Y-DNA 67 tests processed through FTDNA so the testing should have been consistent. Testing procedures are in place so that results are accurate and meet the high standards expected by clients. If multiple nulls do occur, quality control takes a second and third look to verify the results. In my case it was over three months before my results were received. When they arrived I was surprised to find 14 nulls in the results. I believed that a testing error had occurred and contacted FTDNA to request a retest. They refused, saying that they had performed numerous retests to verify the accuracy of the results.
I gave my two sons Y-DNA tests for Christmas. To cut a long story short, after another long wait due to retesting to verify results, their test results matched exactly with mine. All 14 nulls in the same loci were there! Since processing is done in the same manner for all batches, it is unlikely that my sons' results would different from what they are.
The Y-DNA 37 test revealed six nulls. DYS458, DYS455, DYS454, DYS449, DYS576, DYS570.
The Y-DNA 67 test revealed eight more nulls DYS531, DYS590, DYS425, DYS450, DYS481, DYS520, DYS568, DYS487.
Since then I have learned that five more nulls appear at DYS522, DYS575, DYS463, DYS525, and DYS532.
The total number of nulls through Y-111 is 19. Yes, unbelievable!!! I am finding others with identical nulls in these locations. The only matches I get are for Y-12. The nulls result in mismatches because they exceed the cutoff of 4 at FTDNA. It is impossible to get matches with 25, 37, 67 and 111 testers because of the number of nulls. I have a few matches with others at 25, 37 and 67 who also have the same null values.
The rarity of so many nulls, and the fact that we are healthy, intelligent, teachers, electrical engineers and computer forensics technicians prove that the missing DNA has not been harmful to us. In fact many men in the family live long lives.
I am the Admin for the Prouse Project at FTDNA. We currently have seven members with multiple nulls in the locations described above. Several others with very similar nulls are known, but have not joined our project. Multiple nulls could potentially serve as branch-defining markers which could be helpful for genealogy research. Anyone with nulls is encouraged to join the relevant projects.
I am interested in participating with others who also have a huge number of deletions. If there is a group or an individual who is researching nulls, I would like to join with you to learn and see how this unique set of results can help or hinder our genetic genealogy research.