Objective: To determine the presence or absence of the deleted in azoospermia (DAZ) gene clusters in the Y-bearing spermatozoa in semen of severely oligozoospermic men or in testicular biopsy samples of azoospermic men with somatic DAZ deletions.
Design: Prospective study.
Setting: Academic hospital.
Patient(s): Nineteen patients attending our clinics for therapeutic intracytoplasmic injection of sperm.
Intervention(s): Peripheral blood lymphocytes were used to obtain somatic DNA for analysis using the polymerase chain reaction. Analysis of chromosomes X and Y and the detection of the DAZ gene clusters were carried out with the fluorescence in situ hybridization technique in spermatozoa remaining after intracytoplasmic sperm injection.
Main outcome measure(s): Presence or absence of the DAZ gene clusters in matched somatic DNA and Y-bearing spermatozoa.
Result(s): Seven patients appeared to have a somatic DAZ deletion. Three-color fluorescence in situ hybridization showed that all Y-bearing spermatozoa examined from these men carried the same deletion.
Conclusion(s): The DAZ deletions present in the seven men would all have been transmitted if they had fathered sons through artificial fertilization techniques using the sperm cells examined in this study.