Chromosomes of human sperm: variability among normal individuals

Area of Science:

• Human genetics
• Reproductive biology
• Cytogenetics

Background:

• Sperm chromosome analysis is crucial for assessing male reproductive health.
• Understanding chromosomal aberrations in sperm is vital for reproductive outcomes.
• Previous studies have indicated variability in sperm chromosome abnormality rates.

Purpose of the Study:

• To investigate the frequency and types of chromosomal abnormalities in human sperm cells.
• To compare sperm chromosome aberration rates among different individuals.
• To evaluate the relationship between sperm chromosome abnormalities and donor characteristics.

Main Methods:

• Fusion of human sperm with hamster eggs to analyze sperm chromosome constitution.
• Cytogenetic analysis of 2468 human sperm cells.
• Comparison of sperm chromosome aberration frequencies with lymphocyte aberration frequencies.

Main Results:

• Overall frequency of structural aberrations was 7.7% (range 1.9%-15.8%), with significant individual variation.
• Highest aberration frequency observed in the oldest donor (49 years), with a history of vasectomy reversal.
• Overall aneuploidy frequency was 1.7% (range 0.6%-3.1%).
• Sperm cells exhibited higher structural aberration rates than lymphocytes in 9 out of 10 donors.
• Resampled donors showed consistent sperm chromosome abnormality frequencies over time.

Conclusions:

• Human sperm chromosome analysis reveals substantial inter-individual variability in structural aberrations and aneuploidy.
• Sperm chromosome abnormality rates may be influenced by factors such as age and prior medical history.
• Sperm chromosome analysis provides a valuable tool for assessing male germline genetic integrity.