Transmission of Y chromosomal microdeletions from father to son through intracytoplasmic sperm injection.

We conducted chromosomal analysis of three male infants fathered by severe oligozoospermic males with Y chromosomal microdeletions through intracytoplasmic sperm injection (ICSI). Two of the infants had the same Y chromosomal microdeletions as their fathers. The third infant also had a Y chromosomal microdeletion, which was longer than that found in his father. The results confirm that Y chromosomal microdeletions are transmitted from a father to a son via ICSI and also suggest that the microdeletions may be expanded during such transmission. Genetic counseling for infertile couples contemplating ICSI is important if the male carries Y chromosomal microdeletions.