Why did Chris’s sperm alter since transplants aren’t supposed to impact it? According to Mehrdad Abedi, Chris’ doctor, his sperm alteration was most likely caused by his vasectomy. Time will tell.

Because sperm cannot migrate, their DNA changes. Would the same result occur if Chris had not undergone a vasectomy? We don’t know, and scientists can’t test it on Chris. Previously, sperm DNA studies revealed the donor’s DNA rather than the patient’s.