An unknown cousin of my jewish husband had fathered children via sperm donation



Should I get


I am a blogger and genetic genealogist who has helped many people solve family mysteries with DNA

 This includes many adoptees and unknown father cases

 Jewish DNA is particularly tough because of endogamy which makes DNA matches look closer than they are

The first time I was contacted by the child of a sperm donor, I realized that it was different. She was so angry not to have been told! It was clearly more complicated than the usual unknown father case. Here the donors were usually promised anonymity and parents were advised not to tell the child

My personal feeling about sperm donor children is that they have a right to know their heritage and medical risks, but no right to a relationship

The prevalence of personal DNA testing has taken away the anonymity of sperm donors

Some donors when found want no contact, others are excited, but most are just happy to have helped someone else have a family

My Husband got this message on 23andme

The basic methodology for finding an unknown father is to put DNA cousins into 2 groups and find where they meet to create a son

The problem with Jewish DNA is that everyone is related multiple times, in other words, endogamous, so you need 2nd cousin matches to solve unknown parentage cases

screenshot from my tree at

I quickly replied and found she had two other half siblings on 23andme, just discovered, also from the same sperm donor in the 1970s in NYC

Sam, Ethan, and Tamara half siblings compared to Steve

You need large segments to be confident that matches like these are not further away  than predicted due to endogamy

My rule of thumb for true 2nd/3rd cousin Jewish matches  is that you need at least one segment > 20 cM and another > 10 cM among five or more segments

Ethan and Tamara met that criteria but not Sam

Sam's largest segments are well below my threshold for a real jewish 2nd/3rd cousin. Unlike the others, his mother was not Jewish.

Because of the 30+ year age difference, these half siblings are likely in a different generation from Steve which could explain this - Steve also was a late in life baby

Always look up the cMs shared at DNApainter for the possibilities. Subtract any segments less than 7 cM, also subtract the X

So the likely relationships are 2C 1/2R or 1C 2/3R or even 3rd1R if endogamy added extra cMs

Did you notice that Tamara did not share X with Steve? The same was true for Fay, another female match. Since his X comes from his mother, the relationship is more likely on his paternal side or possibly his mother's father's father 

Steve had no known possibilities among his paternal first cousins except the sons of Mignon

"Tom", one of Mignon's grandsons was tested at 23andme and had no significant matches to our group

Tom's high match to Steve eliminates the possibility of his Dad or Uncle being the sperm donor with his low matches to our group.

Tom is Steve's 1C2R, and only half AJ

This is often a problem with Eastern European Jews, no knowledge of their great grandparents. Perhaps a desire to forget the old country

So what paternal 2nd cousins does Steve have?

Sadly Steve knew almost nothing about his father's parents much less their parents and no known 2nd cousins ... so we were at a dead end for the time being

screenshot from Steve's tree at

Genetic Genealogy is often a waiting game

We were hoping for some more matches for Steve that will help build his tree

May 2020: I  blogged about 23andme's new tree build from DNA noting that my 100% Jewish husband got all his relatives assigned to one side  

This got my friend Israel Pickholtz to offer to help with his paternal tree  

Meanwhile Ethan and Stan had their results come in at Ancestry.

 I got them to share their results with me so I could see how much they shared with Steve's best matches. I sent them this link 

SURPRISE: Ethan had good matches to several other close DNA cousins of Steve's one of whom, Mina, was an active genealogist

If you click on your match's name on the DNA match page it takes you to their account overview page which shows the last login and other information

I did not know at the time how these matches were related but I saw that they were descended from the Igel/Eagle family of Solotwina and I knew Steve's mother's father's TIEGER family was from there

So I contacted researcher Yoav who was building a massive family tree for Solotwina over at MyHeritage for help to try and figure it out

sceenshot of Igel/Eagle tree at MyHeritage

If we presume Malka TIEGER Igel was the sister of Steve's grandfather Markus TIEGER then all these matches are Steve's 2C1Rs

Putting in a fake set of parents for Malka and Markus got Ancestry to show this relationship pathway to Mina using ThruLines

My new theory was that the father of the siblings was a second cousin once removed of Steve's, possibly on the Eagle/Igel line

Problem: the parents of Markus and Malka were still unknown and so were their other siblings who could be the ancestors we were looking for, from Solotvin

Next we did some target testing

  • another Eagle cousin
  • another person Yoav found with the surname Tieger from Solotwina ... no luck

Ethan also tested his Y, no luck

I tried looking through what records I could find for Solotwina, with Yoav's help, not many online

Meanwhile my husband's cancer took a turn for the worse. He died a week before his 74th birthday.

Eagle side cousin Mina did a great job of tree building ...  it soon became clear that the sibs were from another yet unknown sibling of Markus and Malka

Back to waiting for another match or more indexed records

 Steven Mark Cooper 1947-2021

Two weeks after Steve's death I checked his matches and saw one at Family Tree DNA with the surname of a late maternal TIEGER first cousin.  In a weird coincidence, the match date was on Steve's birthday

I  sent him an email. Is your mother’s maiden name Tieger? Are you my husband’s first cousin once removed? Yes was the answer, and maybe get in touch with my dad Ed, he is the genealogist in the family.

Never underestimate a fellow genealogist. Elton's father Ed had been in touch with a Tieger side cousin who had provided him with names from a large family tree  Now I had Steve's great grandparents' names and the names and descendants of their children

screenshot from descendant list view at

Ed put me in touch with that cousin, Doug, who had hand drawn a huge tree back in the 1970s when interviewing his grandmother (upstairs) for a school  anthropology project: it showed Malka and Marcus as sibs

In my conversations with Doug, he told me that his brother Ian had been a sperm donor back in NYC in the 1970s. Oh my!! Could it be this easy? Ethan quickly sent out kits to Doug and Ian. Meanwhile I built the tree for Ian’s other ancestors and saw many matches from his other lines to the half sibs; so I told them I was fairly certain that their bio Dad was found.

As I expected, Steve's relationship to the sperm donor Ian is 2nd cousin once removed so the siblings are his 2nd cousins twice removed

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