A man born without testicles may soon be able to father children after receiving a donated testicle from his identical twin brother. Given that his twin's DNA is virtually the same as his own, this means that any DNA he passes on to his children will be nearly an exact match of his own.
The 36-year-old from Serbia was successfully given the donor testicle during a 6-hour operation last week, the New York Times reports. The tricky operation involved connecting two arteries and veins together, which are less than 2 millimeters wide. The testicle needs to be attached to the patient within 2-4 hours and connected to a blood supply before it becomes unviable. This is only the third time this type of transplant has ever been carried out.
The team successfully attached the testicle to the recipient, and both patients (who have chosen to remain anonymous) are said to be in good health.
Two members of the surgical team, Dr Dicken Ko and Dr Branko Bojovic, were also involved in the US' first penis transplant carried out in 2016 on a man who lost his penis to cancer. During that operation, the testicles were not transferred from the donor due to the fact any transplanted testicles will always create the donor's sperm, meaning any children fathered by the recipient would be the genetic offspring of the donor.
“If you were to transplant testicles, that would effectively be making the donor not only a donor of body parts, but also a donor of sperm,” Jeffrey Kahn, director of the Johns Hopkins Berman Institute of Bioethics told The Verge last year, when the first-ever penis and scrotum transplant was performed on a US military veteran injured in Afghanistan. “It’s effectively a sperm donation without consent — and that shouldn’t happen.”
However, in this case, the donor – the recipient's identical twin – was happy to donate his genetic material to his brother. In fact, the brothers sought out lead surgeon Dr Miroslav Djordjevic after they heard he successfully transplanted a uterus between twin sisters, which allowed the recipient to give birth.
Since their DNA is (virtually) identical, he'll be able to pass on genes that are at least nearly exactly his to any children he fathers. As an added bonus, the recipient will also not have to take any immunosuppressants in order to stop his body from rejecting the tissue.
Unfortunately, the doctors were unable to create an artificial "vas deferens" – a tiny muscular tube used to carry sperm out of the testicles – because they were unable to locate tissue needed to create this connection, meaning he will require another operation in order to reproduce normally, or else extract sperm from his testicle or get donor sperm from his brother.
As well as hopefully allowing him to have children, the transplant was intended to stabilize his hormone levels without having to take injections. The surgeons told the New York Times that the surgery could have applications for the injured, cancer patients, and transgender people looking to transition in the future.
[H/T: New York Times]