Microdeletions in the Azoospermia Factor Region on the Y Chromosome Long Arm of Males with Idiopathic Azoospermia

Paick, Jae Seung; Kim, Ki Dong; Kim, Soo Woong

Abstract

PURPOSE: Idiopathic azoospermia is the most common cause of male infertility Recently, much efforts have been focused on possible genetic etiologies. Mutations in the region of the Y chromosome long arm(Yq), known as the azoospermia factor(AZF) region, have been suggested. In the present study, we analysed Korean azoospermic men with cytologically normal Y chromosomes to examine possible genetic variations In regions of Yq, known to be associated with impaired spermatogenesis.
MATERIALS AND METHODS
A total of 63 idiopathic azoospermic subiects were examined. Other cases Included in this study are as follows; 13 subjects with oligospermia, 12 subjects with chromosomal anomalies(eleven 47XXY patients, one 46xx male) and 2 normal subjects. Genomic DNAs were isolated from peripheral blood samples. Each sample was examined for the presence or absence of a total of 28 Y-DNA landmarks in the Yq including DAZ and RBM. To facilitate the analysis, we adopted multiplex PCR where simultaneous amplification of several targets is possible in a single reaction.
RESULTS
We detected deletions of small, interstitial portions of the Yq In a total of 14 azoospermia patients(22.2%). Deletion incidence were 14.3% for DAZ and 17.5% for other loci(sy157, sy153, sy127, sy109). But deletion of RBM was not detected. Multiple deletions were found in 4 subjects. One patient with 47XXY and one patient with 46xx male also showed multiple deletions. However, testis biopsies revealed diverse histologic appearances in these subjects.
CONCLUSIONS
As other deletions than DAZ were also found within AZF region, it is possible that normal spermatogenesis may be regulated by more than one locus in the Y chromosome; thus, it has yet to be waited to correlate genetic causatives and testicular phenotypes.