Cytogenetic abnormalities and Y-chromosome microdeletions in infertile Syrian males

Abstract

Infertility is an important health issue affecting numerous couples. Approximately 30-50% of the cases of male infertility is due to unknown reasons. The main genetic factors involved in male infertility are chromosomal abnormalities and Y chromosome microdeletions within the Yq11 region. The genes controlling spermatogenesis located in the Yq11 region are termed azoospermia factor genes (AZF). Klinefelter syndrome (KS) is the most common of the chromosomal anomalies in the infertile male. AZF microdeletions on the Y chromosome are the most frequent genetic cause of male infertility. Screening for microdeletions in the AZFa, b and c regions of the Y chromosome showed a marked variation among different studies. The present study aimed to investigate the prevalence of such deletions in Syrian men. A total of 162 infertile males (97 azoospermic, 49 oligospermic and 16 severely oligospermic) were screened for chromosomal abnormalities and Y chromosome microdeletions using 28 markers in the AZF region. Twenty (12.34%) patients had chromosomal rearrangements, 17 of them showed sex chromosome abnormalities (11 of 17 patients within the azoospermic group had a KS of 64.7%), 2 patients had apparently balanced autosomal rearrangements, while 1 patient had an inversion. Of the 162 infertile men, 46 patients (28.4%) had Y chromosome microdeletions within the AZF-regions. Most frequently hit were the AZFc (34.8%), followed by the AZFbc, AZFa, AZFac, AZFbc, AZFb, AZFd, AZFab, AZFad, AZFbd, AZFabc and the AZFbcd. Combined AZF deletions involving three regions with chromosomal abnormalities were observed in one case. The higher frequency of AZF deletions in our study was comparable with frequencies in other countries and regions of the world, possibly due to the elevated number of the sequence-tagged site (STS) markers used for this screening.

The Frequency of Chromosomal Abnormalities and Y Chromosome Microdeletions in Infertile Non-Obstructive Azoospermic and Severe Oligozoospermic Males

“…These results supports the previous notion that sex chromosome abnormalities are more frequent in men with azoospermia, while autosomal abnormalities are more frequent in oligozoospermic men [25,32,35,37,40 -42] . KS is the most frequent sex chromosome abnormality among our patients, 127/ 135(94.1%), and this is in accordance with other studies [4,18,23,33,34,43,44] .…”

“…In our research, Tthe frequency of numerical chromosomal abnormalities in our study iwas higher than the structural type (11.8% versus 2.4%). Several studies [4,20,28,31,33,38,39] reported similar result [4,20,28,31,33,38,39] . However, in other studies, the frequency of structural abnormalities was higher than numerical ones [18,32] .…”

“…Genetic abnormalities are found in about 5-10% of oligozoospermic and in 15-20% of azoospermic cases [2] . Including numerical and structural chromosomal abnormalities and AZF microdeletions [3,4] .…”

Efecto de la microdeleción en la región AZF sobre marcadores forenses del cromosoma Y

“…Sin embargo, a excepción de los Países Bajos no existe ningún otro país con leyes específicas que permitan utilizar este tipo de evidencia en la casuística actual [28,29].…”

Development and implementation of a novel panel consisting 20 markers for the detection of genetic causes of male infertility

“…Because symptoms are common with other diseases, it is usually underdiagnosed (Abramsky & Chapple, ). Amplification of sequence‐tagged sites (STS) markers using PCR‐based methods is known as a standard technique for detecting AZF microdeletions (Al‐Achkar, Wafa, & Moassass, ; Ambulkar et al., ). The AZF loci are located on the long arm of the Y chromosome (Yq) which contains genes required for normal spermatogenesis (Pryor et al., ).…”