Abstract: BACKGRONUD ＆ AIM: To investigate the relationship between spermatogenesis disorder and genetic defects of patients with azoospermia or severe oligospermia. MATERIAL AND METHODS: G banding karyotype analysis of peripheral blood lymphocytes from 205 cases with azoospermia and 39 cases with severe oligospermia were performed and the multipolymerase chain reactions(PCR) for Y-chromosome microdeletion screening in the blood from 36 cases of azoospermia with normal karyotype were done. RESULTS: The incidence of abnormal chromosome karyotype was 30.33 ％(74 cases) in cases with azoospermia and severe oligospermia group and 3.33 ％(1 case)in the control group respectively.3 cases with microdeletion in different segments of Azoospermia Factors(AZF)region on Y-chromosome were found in 36 cases of azoospermia with normal karyotype, and the microdeletion rate was 8.33 ％. No microdeletion in corresponding sites was discovered in the control group. CONCLUSION: Both of abnormal chromosome karyotype and Y-chromosome microdeletion are important to cause azoospermia and severe oligospermia. It is more accurate and effective in evaluating the genetic defect of the patients with azoospermia or severe oligospermia to combine two methods of karyotype analysis and microdeletion screening, which can offer the patients with etiologic diagnosis, genetic counseling and choices for therapeutic strategies.

Key words: azoospermia, oligospermia, chromosome karyotype, multipolymerase(PCR), gene microdeletion