From these, sperm from 40 randomly selected men with no DAZ microdeletions in their leukocytes (n = 10 oligozoospermia; n = 10 asthenozoospermia; n = 10 oligoasthenozoospermia; and n = 10 near-azoospermia) were were compared to sperm from men of normal semen quality (n = 10) using combined primed in situ labelling and fluorescent in situ hybridization (PRINS-FISH) technique as well as screening for sex chromosome aneuploidy.
In men with AZFc subdeltions, loss of two DAZ and one CDY1 gene copy made them highly susceptible to azoospermia and severe oligozoospermia with OR of 29.7 and 26, respectively.
More interestingly, partial DAZ1/2 deletion was associated with azoospermia (ORs=2.63, 95%CI: 1.19-5.81, I(2)=64.7%) and oligozoospermia (ORs=2.53, 95%CI: 1.40-4.57, I(2)=51.8%), but partial DAZ3/4 deletion was not associated with azoospermia (ORs=0.71, 95%CI: 0.23-2.22, I(2)=71.7%,) and oligozoospermia (ORs=1.21, 95%CI: 0.65-2.24, I(2)=55.5%).
Analysis of DAZ gene copies in Tunisian population, suggested that the simultaneous deletion of DAZ2 and DAZ4 gene copies is associated with male infertility, and that oligospermia seems to be promoted by removing DAZ4 copy.
Although AZFc is deleted in azoospermia or oligozoospermia, no definitive conclusion has been drawn for the role of partial AZFc deletions to spermatogenic failure.
gr/gr deletions were analyzed by using markers sY1291, sY1191 and sY1197 and by investigating the presence of single nucleotide variants (SNV) in DAZ and CDY1 genes in patients with azoospermia (n = 44), cryptozoospermia (n = 51) or severe oligozoospermia (n = 92).
Copy deletion screening of DAZ gene family on the Y chromosome in 485 patients with idiopathic azoospermia or oligozoospermia and 236 fertile men revealed that the prevalence of deletion patterns of the entire DAZ gene and DAZ1/DAZ2 gene were significantly higher in the patients than in fertile men.
We conclude that partial deletions of the DAZ genes are associated with oligozoospermia but not with azoospermia; however, an increased number of DAZ genes does not seem to be a statistically significant risk factor for spermatogenic failure.
The transcript ratios for BOULE, DAZL, and DAZ were significantly decreased in tissues with spermatogenic failure (hypospermatogenesis, maturation arrest, and Sertoli cell-only).
To uncover the functional contribution of DAZ to human spermatogenesis, a DAZ gene copy-specific deletion analysis was previously established and showed that DAZ1/DAZ2 deletions associate with oligozoospermia.
Twelve of 101 patients (12%) with the AZFc/DAZ microdeletion were found, including 8 with azoospermia (11%) and 4 with severe oligozoospermia (14.3%), and 1 patient had a AZFb and AZFc/DAZ double deletion.
With these diagnostic tools, 63 DNA samples from men with idiopathic oligozoospermia and 107 DNA samples from men with proven fertility were analysed for the presence of the complete DAZ gene locus, encompassing the four DAZ gene copies.
This procedure could be particularly useful in screening for the DAZ locus in the diagnostic workup of nonobstructive azoospermia and severe oligoasthenoteratozoospermia.
In a subset of infertile men, a spectrum of spermatogenic defects ranging from a complete absence of germ cells (sertoli cell only) to oligozoospermia is associated with microdeletions of the DAZ (deleted in azoospermia) gene cluster on human distal Yq.
Deletions in the AZFc region involving the DAZ gene were the most frequent finding and they were more often observed in severe hypospermatogenesis than in Sertoli cell-only syndrome, suggesting that deletions of this region are not sufficient to cause complete loss of the spermatogenic line.
The DAZLA (DAZ Like Autosomal) gene on human chromosome 3 shares a high degree of homology with the DAZ (Deleted in AZoospermia) gene family on the Y chromosome, a gene family frequently deleted in males with azoospermia or severe oligospermia.