This document summarizes a study that evaluated sperm function and aneuploidies in single sperm cells selected from patients with severe testicular damage (Group A) compared to normal sperm (Group B). The study found that sperm cells in Group A had higher levels of mitochondrial DNA damage (52.2% vs 13.3%), nuclear DNA damage (71.9% vs 5.3%), and DNA fragmentation (40.1% vs 9.3%) compared to Group B. Additionally, the rate of aneuploidies was higher in Group A at 5.1% compared to 0% in Group B.