Ancestor DNA Reveals Shocking Truth: Nine Half-Siblings Traced to Mother’s Doctor

When Joseph Laedtke received his ancestry DNA test results in December 2024, he discovered he had nine half-siblings, all linked to his mother’s former doctor, Dr. Frederick Dettmann. Mary Ellen Lukezich and her late husband, Thomas Laedtke, consulted Dettmann in the early 1980s due to infertility issues. They spent two years undergoing fertility treatments before agreeing to artificial insemination with donor sperm.

Lukezich recalled Dettmann recommending donor sperm from a medical student, assuring her the donor was unlikely to donate again, resided out of state, and closely matched her and her husband’s appearance. Driven by her desire to become a mother, she followed Dettmann’s guidance.

The couple kept their decision to use donor sperm private, believing it was a personal journey. “I became pregnant, everyone was happy, and that was the end of the story,” Lukezich said. Afterward, attempts to conceive again were unsuccessful.

Only when her son, now 43, submitted his DNA to a genetic testing company did she learn her doctor might have used his own sperm. Laedtke submitted his DNA in November 2024, not expecting significant revelations.

“Ancestry emailed me, saying I had a half-sister,” Laedtke shared. “When I checked my DNA results and relationships, I saw multiple suggested half-siblings.” He immediately contacted his mother, learning for the first time about the use of donor sperm. Lukezich was shocked to hear Dettmann was a potential donor.

Laedtke identified Dettmann as the donor through genealogy tools on Ancestry. His mother was overwhelmed when he informed her. Initially, Laedtke wished his late father, who died in 2005, was present during this discovery. As he processed the situation, feelings of disgust and betrayal emerged.

“What Dettmann did was incomprehensible, a betrayal of trust. I want to ensure he’s held accountable for the pain he caused my mom,” Laedtke expressed.

Lukezich described the revelation as a violation. “I feel like I’ve been raped. It’s not right, and I want other women to feel empowered to come forward.”

Al Foeckler, their attorney, reported multiple women contacting him about unpleasant experiences with Dettmann dating back to the 1970s. “He was a serial predator of women,” Foeckler stated. Dettmann, now 91, retired in the 1990s and resides in Arizona.

Attorney Sean Gaynor, on behalf of Dettmann, said Dettmann is aware of the claims but cannot discuss patient care due to privacy laws. “The alleged events occurred nearly 50 years ago,” Gaynor stated, noting Dettmann lacks independent recollection of the allegations.

In 1985, a report surfaced of Dettmann assaulting a woman during a gynecological exam, but no charges were pursued due to insufficient proof. The Wisconsin medical licensing board dismissed the complaint in 1986, and no open investigations exist against Dettmann currently. The Department of Safety and Professional Services holds no records of such old complaints.

Gaynor’s statement noted Dettmann never faced lawsuits, disciplinary actions, investigations, or ethical complaints during his career.