The aim of this study was to establish the prevalence of Y chromosomal microdeletions in infertile Tunisian men. Three groups of infertile men, 65 normospermic, 53 oligozoospermic and 45 azoospermic, were tested for Yq microdeletions detection by multiplex polymerase chain reaction (PCR) using specific Y chromosome AZF regions tagged site markers (STS). One group of 13 healthy men was used as the control group. Six STS were tested (2 in each AZF region). The general prevalence of AZF microdeletions was 16%; in azoospermia and severe oligospermia groups, it was higher (29% and 30.5%, respectively). Significant differences were found with moderate oligospermic and normospermic groups (p < 0,05). AZFc microdeletions were the most frequent, and 55% of AZFc deleted patients were oligospermic. No deletions were detected in the control group. These results add to the growing literature data, showing that microdeletions of the Y chromosome is an important cause of severe spermatogenetic defect and confirm that deletion in AZFc region is the most common and is compatible with residual spermatogenesis.

Microdeletions in Yq11 are a common molecular cause of spermatogenic failure in men and are recurrently detected in about 10-15% of idiopathic azoospermia and severe oligozoospermia. Screening for AZF microdeletions is often performed by multiplex PCR. AZFc deletions, involving the DAZ gene, form the majority of these deletions. The aim of this study was to evaluate in a group of 34 Tunisian infertile patients (16 oligozoospermic and 18 azoospermic men) the prevalence of DAZ microdeletions using a rapid molecular strategy: the PCR-DGGE method based on the high degree of homology between the DAZ gene and its autosomally equivalent DAZLA gene. DAZ microdeletions were detected in 8.8% of patients. The three deleted patients have a 46, XY karyotype. Two of them were azoospermic and the other had an extreme oligo-asthenoteratozoospermia with a predominant abnormality: small round head spermatozoa (Y46). Our findings suggest that PCR-DGGE method, for detection of DAZ gene deletion, could be particularly useful as a first step in the diagnosis workup of nonobstructive azoospermia and severe oligozoospermia for three reasons. First, it is a simple and fast system; second, DAZ microdeletions are the most common Y deletions; and third, partial DAZ microdeletions and mosaicism may be recognized by PCR-DGGE while only deletions removing the whole DAZ gene cluster can be detected by STS-PCR [211]. Nevertheless, this procedure has limitations because other deletions of AZFa and AZFb may go undetected. Therefore, molecular investigation by multiplex PCR must be conducted in a second step according to European guidelines for the molecular diagnosis of Y chromosome microdeletions, particularly before ICSI procedures.