A DNA test linked a Wisconsin woman’s son to nine half-siblings and to her former gynecologist, triggering a lawsuit against Dr. Frederick Dettmann.
A DNA test has pushed a Wisconsin family into court after it linked a son to nine half-siblings and to the former OB-GYN who treated his mother decades ago. Mary Ellen Lukezich and her son, Joe Laedtke, are suing Dr. Frederick Dettmann after the family says the genetic results pointed to him as the sperm donor used to conceive Laedtke.
Lukezich sought fertility treatment from Dettmann in the early 1980s with her late husband, Thomas Laedtke, after the couple struggled to conceive. The family says they ultimately agreed to artificial insemination. Lukezich recalled that Dettmann suggested using what she believed was a medical student’s donated sperm because the donor lived out of state and resembled her and her husband. She said she trusted her doctor and followed his advice. Laedtke was later born as the couple’s only child.
That long-ago medical decision came back into focus when Laedtke took an Ancestry DNA test in December 2024 out of curiosity. He said the results first showed a half-sister, then led him to notice multiple half-siblings among his matches. After calling his mother, he learned the test suggested Dettmann was the donor. Laedtke said the discovery left him feeling disgust and disappointment over what he sees as a grave breach of trust. Lukezich described the revelation in even starker terms, saying, “I feel like I’ve been raped.”
The family filed suit last week. Their attorney, Al Foeckler, said other women have contacted him since the family went public, describing troubling interactions with Dettmann that dated back to the 1970s. Foeckler said he believes the case involves more than one patient and urged others who may have been affected to come forward. The lawsuit does not ask for a set amount of damages, leaving the question of compensation to be decided at trial.
“A DNA test linked a Wisconsin woman’s son to nine half-siblings and to her former gynecologist, triggering a lawsuit against Dr. Frederick Dettmann.”
Dettmann is 91 and retired in the 1990s. He now lives in Arizona. His attorney, Sean Gaynor, said Dettmann is aware of the allegations but cannot address them because of privacy laws. Gaynor said the events at issue are alleged to have happened nearly 50 years ago and that Dettmann has no independent memory of the people making the claims or evidence supporting them.
The lawsuit has also revived older questions about Dettmann’s conduct. A complaint filed in 1985 by the husband of one of his patients accused him of assaulting her during a gynecological exam in Wisconsin, but the doctor denied the allegation and the charges were later dismissed because it was considered too difficult to prove inappropriate conduct. Records show the matter was reported to the medical licensing board and then closed in 1986 after a vote and review of the facts.
Whitefish Bay Police Chief Patrick Whitaker said any case records would have been destroyed under state retention rules, and he said there is no open investigation into Dettmann in that department. Gaynor also said Dettmann was never sued, disciplined, investigated, had his license challenged, or faced ethical complaints. The family’s case now puts a decades-old medical relationship back under scrutiny, and it is likely to draw attention from other patients who may wonder whether they, too, were affected by the same doctor. For American readers, the case is a stark reminder of how deeply trust can be damaged when a physician crosses the line between care and abuse.
Frequently asked questions
What triggered the lawsuit against Dr. Frederick Dettmann?
Joe Laedtke’s December 2024 DNA test showed multiple half-siblings and suggested Dettmann was his biological father. That discovery led the family to sue.
What did Mary Ellen Lukezich believe at the time of her fertility treatment?
She says Dettmann told her to use what she believed was a medical student’s donated sperm. She said she trusted him and agreed to the procedure.
How has Dettmann responded to the allegations?
His attorney said he is aware of the claims but cannot address them because of privacy laws. The attorney also said Dettmann has no independent recollection of the accusers and knows of no evidence supporting the claims.
Is there an active police investigation?
Whitefish Bay Police Chief Patrick Whitaker said there is no open investigation with the department. He also said any case records would have been destroyed under state retention laws.
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