Y Chromosome Microdeletions in Infertile Men With Idiopathic Oligo- or Azoospermia

About 30–40% of male infertility is due to unknown reasons. Genetic contributions to the disruption of spermatogenesis are suggested and amongst the genetic factors studied, Y chromosome microdeletions represent the most common one. Screening for microdeletions in AZFa, b and c region of Y chromosome showed a big variation among different studies. The purpose of this study was to investigate the prevalence of such deletions in Saudi men. A total of 257 patients with idiopathic oligoor azoospermia were screened for Y chromosome microdeletions by 19 markers in AZF region. Ten (3.9%) patients had chromosomal rearrangements, six of them showed sex chromosome abnormalities and four patients had apparently balanced autosomal rearrengements. Eight of the remaining 247 patients (3.2%) with a normal karyotype and no known causes of impaired spermatogenesis had Y chromosome microdeletions. Among these, six patients had deletions in AZFc region, one case had a deletion in AZFb and another had both AZFa and AZFc deletions. In conclusion, our study shows that Y chromosome microdeletions are low in our population. We also report for the first time a case with unique point deletions of AZFa and AZFc regions. The lower frequency of deletions in our study suggest that other genetic, epigenetic, nutritional and local factors may be responsible for idiopathic oligoor azoospermia in the Saudi population. Introduction Approximately 10–15% of couples are affected by infertility. A male factor can be diagnosed in approximately 50% of them and about 30–40% of male infertility is due to unknown origin [1]. Little is known about the genetic disorders that cause disruption of spermatogenesis. Early cytogenetic studies showed that microscopic deletions in the long arm of Y chromosome are responsible for azoospermia [2]. With the advancement in molecular biology, three non-overlapping regions named "azoospermia factors" (AZFa, b, c from proximal to distal Yq region) have been defined as spermatogenesis loci [3]. It is now widely accepted that deletions within those three regions severely diminish the sperm production [4]. The power of polymerase chain reaction (PCR) and the availability of sequence-tagged site (STS) maps made possible the detection of interstitial deletions in Yq11 region that was invisible by karyotyping [5]. Such microdeletions have been reported with varied prevalence in different populations and studies [6]. The introduction of intracytoplasmic sperm injection (ICSI) into the treatment of male factor infertility [7] permitted the use of sperm from oligoor azoospermic patients to achieve successful fertilization and pregnancies. This technology raised both hopes for infertile men to have their own child, which would be otherwise impossible and concerns to medical professionals about inheritance of Y chromosome deletions and genetic disorders to the next generations. Although these patients have a right to father a child with the current technology, however, they should be counseled about the risk they are transmitting to their offspring [8]. The aim of this study was to screen for Y chromosome microdeletions in infertile males who were candidate for ICSI treatment and with idiopathic oligoor azoospermia.