SCREENING FOR DELETIONS OF THE Y-CHROMOSOME INVOLVING THE DAZ (DELETED IN AZOOSPERMIA) GENE IN AZOOSPERMIA AND SEVERE OLIGOZOOSPERMIA

Objective: To evaluate the occurrence and prevalence of microdeletions of the Y chromosome involving the DAZ (Deleted in AZoospermia) gene i n patients with azoospermia or severe oligozoospermia. Design: Control led clinical study. Setting: University infertility clinic. Patient(s) : Infertile men (n = 168) with nonobstructive, idiopathic azoospermia or severe oligozoospermia and normal LH. The control group consisted o f proven fathers (n = 86). Intervention(s): None. Main Outcome Measure (s): Semen analysis; polymerase chain reaction amplification of the lo ci sY84, sY143, sY254, and sY255; serum FSH, LH, and T; testicular vol ume. Result(s): Deletions involving the sY254 and sY255 DAZ loci were found in three azoospermic patients and two men with sperm concentrati on <1 x 10(6)/mL. Serum FSH was elevated in four patients and was norm al in one. All five patients had decreased testicular volumes compared with controls. No deletions involving the sY84 and sY143 loci were fo und. The four loci were amplified normally in the control group. Concl usion(s): The estimated frequency of deletions involving the DAZ locus is 3% in azoospermic-severely oligozoospermic men consulting an infer tility clinic. Polymerase chain reaction amplification of the DAZ locu s is useful for the diagnosis of microdeletions of the Y chromosome. D eletions involving more proximal regions of the Y chromosome seem to b e rare.