Genetics of azoospermia: current knowledge, clinical implications, and future directions. Part II: Y chromosome microdeletions.
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INTRODUCTION: We reviewed the most recent advances in the genetics of male infertility focusing on Y chromosome microdeletions. MATERIALS AND METHODS: We searched the literature using the PubMed and skimmed articles published from January 1998 to October 2007. The keywords were the Y chromosome, microdeletions, male infertility, and azoospermia factor (AZF). The full texts of the relevant articles and their bibliographic information were reviewed and a total of 78 articles were used. RESULTS: Three regions in the long arm of the Y chromosome, known as AZFa, AZFb, and AZFc, are involved in the most frequent patterns of Y chromosome microdeletions. These regions contain a high density of genes that are thought to be responsible for impaired spermatogenesis. In 2003, the Y chromosome sequence was mapped and microdeletions are now classified according to the palindromic structure of the euchromatin that is composed of a series of repeat units called amplicons. Although it has been shown that the AZFb and AZFc are overlapping regions, the classical AZF regions are still used to describe the deletions in clinical practice. CONCLUSION: Y chromosome microdeletions are the most common genetic cause of male infertility and screening for these microdeletions in azoospermic or severely oligospermic men should be standard. Detection of various subtypes of these deletions has a prognostic value in predicting potential success of testicular sperm retrieval for assisted reproduction. Men with azoospermia and AZFc deletions may have retrievable sperm in their testes. However, they will transmit the deletions to their male offspring by intracytoplasmic sperm injection. (+info)
Sperm defect severity rather than sperm Source is associated with lower fertilization rates after intracytoplasmic sperm injection.
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OBJECTIVE: To evaluate the impact of sperm defect severity and the type of azoospermia on the outcomes of intracytoplasmic sperm injection (ICSI). MATERIALS AND METHODS: This study included 313 ICSI cycles that were divided into two major groups according to the source of spermatozoa used for ICSI: 1) Ejaculated (group 1; n = 220) and 2) Testicular/Epididymal (group 2; n = 93). Group 1 was subdivided into four subgroups according to the results of the semen analysis: 1) single defect (oligo-[O] or astheno-[A] or teratozoospermia-[T], n = 41), 2) double defect (a combination of two single defects, n = 45), 3) triple defect (OAT, n = 48), and 4) control (no sperm defects; n = 86). Group 2 was subdivided according to the type of azoospermia: 1) obstructive (OA: n = 39) and 2) non-obstructive (NOA: n = 54). Fertilization (2PN), cleavage, embryo quality, clinical pregnancy and miscarriage rates were statistically compared using one-way ANOVA and Chi-square analyses. RESULTS: Significantly lower fertilization rates were obtained when either ejaculated sperm with triple defect or testicular sperm from NOA patients (63.4 +/- 25.9% and 52.2 +/- 29.3%, respectively) were used for ICSI as compared to other groups ( approximately 73%; P < 0.05). Epididymal and testicular spermatozoa from OA patients fertilized as well as normal or mild/moderate deficient ejaculated sperm. Cleavage, embryo quality, pregnancy and miscarriage rates did not differ statistically between ejaculated and obstructive azoospermia groups. However, fertilization, cleavage and pregnancy rates were significantly lower for NOA patients. CONCLUSION: Lower fertilization rates are achieved when ICSI is performed with sperm from men with oligoasthenoteratozoospermic and non-obstructive azoospermic, and embryo development and pregnancy rates are significantly lower when testicular spermatozoa from NOA men are used. (+info)
Novel UBE2B-associated polymorphisms in an azoospermic/oligozoospermic population.
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Serum inhibin-B and follicle stimulating hormone as predictors of the presence of sperm in testicular fine needle aspirate in men with azoospermia.
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OBJECTIVE: Inhibin-B (Inh-B) is produced by Sertoli cells and controls Follicle Stimulating Hormone (FSH) secretion through a negative feedback mechanism. The primary aim of this study was to compare Iotanh-B with FSH as predictors of the recovery of sperm in testicular fine needle aspirate in men with azoospermia. DESIGN: In 51 men with azoospermia basal values of Luteinizing Hormone (LH), FSH, prolactin and testosterone as well as Inh-B values before and 24 h and 48 h after the administration of 300 IU recombinant human FSH were determined. Testicular Fine Needle Aspiration (FNA) was also carried out. Thirty-one young healthy men were also enrolled in the study as controls. RESULTS: There was significant difference between men with azoospermia and controls with regard to the basal Inh-B levels [median (interquartile range) 37.2 (36) vs. 103.0 (90) pg/mL, respectively, p=0.003] but not to the stimulated Inh-B levels [40.5 (41) vs. 73.0 (44) pg/mL, p=0.113 at 24 h and 34.3 (34) vs. 82.0 (50) pg/mL, p=0.098 at 48 h)]. The Area Under Curve in Receiver Operating Characteristic curves were similar for Inh-B and FSH (0.610 vs. 0.716, respectively, p=0.151) as far as prediction of sperm retrieval is concerned. CONCLUSIONS: Basal serum Inh-B values are significantly lower in men with azoospermia compared to controls. However, Inh-B is not superior to FSH in predicting the presence of sperm in testicular fine needle aspirate. (+info)
Assessment of male fertility in patients with Hodgkin's lymphoma treated in the German Hodgkin Study Group (GHSG) clinical trials.
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