Analysis Of Chromosome Abnormalities And AZF Microdeletions In Infertile Men

Almost half of the infertile men is spermatogenesis defects. Many reasons can cause the male infertility,for example,inborn abnormality in urinogenital system,internal hormone abnormality,infection in genital system, varicocele ,obstruction in spermaductusand so on.There are also hereditism reason cause it,which comprises of molecular genetics reasons. In recent years,there have been intensive studies on the genetic causes underlying male infertility and several genetic etiology were found,such as microdeletion of azoospermia factor(AZF) on the Y chromosome ,numeral and structural abnormality of chromosome and mutations of some known genes.To investigate the importance of AZF microdeletions and chromosomal abnormalities to infertile men assessing the frequency of Y chromosome microdeletions and chromosomal abnormality in ingertile men from Northeastern China. Moreover, to compare the prevalence of these abnormalities with other countries and regions in the world.From March 2009 to November 2010, 551 infertile men were recruited from infertile male patients attending the First Norman Bethune Hospital of Jilin University. Complete semen analyses were performed according to WHO guidelines. reproductive hormones were measured by Radioimmunoassay ;The screening for 9 specific sequence-tagged sites of AZF was performed by multiplex PCR. Karyotype analysis using lymphocyte training of peripheral blood, standard G-banding analysis .Chromosomal abnormalities were found in 62(45 azoospermic men, 14 oligozoospermic and 4 oligo-astenoteratozoospermic men) out of the 551 infertile male patients, corresponding to a frequency of 11%. A total of 28 infertile patients (28/62=45%) had Klinefelter,s syndrome (47, XXY) in the azoospermic and oligozoospermic groups. Chromosome abnormalities in this study mainly involves 1, 2, 3, 4, 13, 14, 15, 18, 21 and X, Y chromosomes, respectively belongs to numerical abnormality,structural aberration of chromosome and chimeras. No abnormal karyotypes were found in the positive fertile control group.In the present study, screening for AZF microdeletions was carried out in the 551 infertile patients as well as 100 fertile male and female controls. Of the 551 infertile cases, AZF region microdeletions on the Y chromosome were detected in 56 infetile male patients with a frenquency of 10.2%. AZF microdeletions were present in 35 patients (9.5% or 35/368) with azoospermia, 17 patients (11% or 17/153) with oligozoospermia and 4 patient (19% or 4/21) with oligo-asteno-teratozoospermia syndrome. All infetile men with complete AZFc and AZFb+c+d deletions had azoospermia. Of 56 cases with AZF microdeletions, the loss of SY254 (96.4%) and SY255 (92.9% ) were commonest, followed by SY152 (67.9%) and SY157 (50%). Notably, the skipping microdeletions were found in the four azoospermic patients, three with AZFb+c+d deletions and one with AZFc+d deletions. The most frequent microdeletions were in the AZFc+d, followed by AZFc, AZFb+c+d and AZFa. No microdeletions was found in the fertile controls. Our research provided important basis to male infertile patients for their clinical diagnosis, treatment and genetic counseling .Supply molecular genetic inspection to infertile male patients ,it is an important supplement to conventional cytogenetic examination.