A mother got a shocking surprise when a DNA test revealed her son had nine half-siblings, all of whom were genetically connected to her former gynecologist.

Mary Ellen Lukezich sought fertility treatments from Dr. Frederick Dettmann in the early 1980s with her late husband, Thomas Laedtke, after the couple had trouble conceiving a child of their own, ultimately deciding to undergo artificial insemination.

Lukezich recalled Dettmann suggested using a medical student’s donated sperm, owing to the fact that he lived out of state and matched her and her husband’s appearance, according to NBC News.

“I was young,” said Lukezich, who is suing the doc. “I so wanted to be a mom that I was going to do anything, and I did whatever he asked me to do.”

She became pregnant and gave birth to her only son, Joe Laedtke, now 43, who took an Ancestry DNA test in December 2024 out of curiosity — only to find the disturbing and unexpected results.

“I got an email from Ancestry, which is the company that I ordered the DNA test from, that I had a half-sister,” Laedtke said.

“And so when I went into my DNA results and the relationships, I had noticed that there was multiple half-siblings that it had suggested that I was related to.”

Laedtke only learned he had been conceived from donor sperm when he called his mother with the news. She was stunned to learn that the results indicated Dettman was the donor, Laedtke said he felt “disgust and disappointment” about the apparent egregious breach of trust by his mother’s doctor.

“What he did was incomprehensible, and it was such a betrayal of trust that I just want to make sure that if I have the opportunity to hold him accountable for the pain that he caused my mom and the things that he put her through that maybe she didn’t even know at the time,” he told the outlet.

“I feel like I’ve been raped,” Lukezich said. “And it’s not right. And I want other women to feel OK about coming forward with this.”

Last week the family filed suit against Dettmann, and their attorney, Al Foeckler, said numerous women have reached out to him since they disclosed their unusual situation, saying they had problematic interactions of their own with Dettmann dating back to the 1970s.

He’s encouraging other women who may have been impacted to come forward.

“There is no question in my mind that this man was a serial predator of women,” Foeckler told NBC News.

The suit does not seek a specific amount of damages and is instead requesting a court determine the amount at the trial.

Dettmann, 91, retired in the 1990s and now lives in Arizona.

His attorney, Sean Gaynor, said in a statement that the former clinician knows of the allegations but is unable to address them because of privacy laws.

“The events referenced are alleged to have occurred almost 50 years ago,” Gaynor said. “Dr. Dettmann has no independent recollection of the individuals making these allegations and is unaware of any evidence supporting the claims being asserted,” Gaynor told the outlet.

A report filed by the husband of one of Dettmann’s patients in 1985 alleging he had assaulted his wife during a gynecological exam in Wisconsin, however the doctor denied the allegations and the charges were later dismissed because it was “too difficult” to prove he had acted inappropriately.

Records show the complaint was reported to the medical licensing board but closed in 1986 after a vote and consideration of the facts.

Whitefish Bay Police Chief Patrick Whitaker told the outlet that any case records would have been destroyed due to the state’s retention laws, and that there is no open investigation into Dettmann with the department.

Gaynor pointed out that Dettmann was “never sued, disciplined, investigated, had his licensure challenged nor were there any ethical complaints made against him.”