Genetic Analysis On Infertile Male Patients

Objective: To investigate the relationship between the male infertility and the genetic causes such as chromosomal abnormality, mutations of SRY and AZF microdeletion. To investigate the microdeletions of AZF gene in genomic DNA from blood and semen of infertile men with oligozoospermia.Methods: This study uses the G-banding method to make the karyotype analysis, and uses polymerase chain reaction(PCR) method to detect the mutations of SRY and Y chromosome microdeletions in the infertile male patients. We select five sequence-tag-sites (STSs) in Y chromosome including AZFa, b, c and d regions, 57 idopathic oligozoospermia and azoospermia patients and 17 normal fertility men were detected. 5 STSs were analysed in PCR analysis: sY86 for AZFa, sY127 and sY134 for AZFb, sY254 for AZFc, sY1 52 for AZFd.Results: 1. ln the peripheral blood samples of the 57 infertile and 17 fertile men, the primers of SRY gene were used as positive controls for PCR. The express of SRY gene was evaluated in order to have an internal control for the DNA isolation and efficiency of the PCR method. 2. In the total of 87 cases, 25 (28.74%) were found to have chromosomal abnormality, 1 (1.15%) had mutation of SRY, 4 (4.60%) showed AZF microdeletions. The total genetic abnormality ratio was 34.49%. 3. PCR analysis in 17 normal fertile men did not deetect any microdeletions of AZF gene, while no amplification was observed in women and blank. Conclusion: 1. Chromosome karyotype analysis is essential to patients with abnormal fertile. To find the exactly causes, it is important to screen for Y chromosome deletions to patients with normal karyotype. 2. Y chromosome microdeletion is one of the major causes of dyszoospermia. To screen for Y chromosome deletions to patients with idiopathic severe oligozoospermia or nonstructive azoospermia is important. 3. AZF deletions could be transmitted by vertical transmission, and would probably result in infertile sons. In cases of idiopathic oligozoospermia and azoospermia, detection of correlated gene may play an important role in the increase of prepotency ratio before starting artificial insemination with husband's semen and intracytoplasmic sperm injection. 4. Chromosomal abnormality and AZF microdeletion on Y chromosome is the important genetic cause of male infertility, and the microdeletion of AZF gene in blood cell genomic DNA is similar to that in semen cell.