Robert D. Oates

The AZFc region of the Y chromosome features massive palindromes and uniform recurrent deletions in infertile men

Deletions of the AZFc (azoospermia factor c) region of the Y chromosome are the most common known cause of spermatogenic failure. We determined the complete nucleotide sequence of AZFc by identifying and distinguishing between near-identical amplicons (massive repeat units) using an iterative mapping–sequencing process. A complex of three palindromes, the largest spanning 3 Mb with 99.97% identity between its arms, encompasses the AZFc region. The palindromes are constructed from six distinct families of amplicons, with unit lengths of 115–678 kb, and may have resulted from tandem duplication and inversion during primate evolution. The palindromic complex contains 11 families of transcription units, all expressed in testis. Deletions of AZFc that cause infertility are remarkably uniform, spanning a 3.5-Mb segment and bounded by 229-kb direct repeats that probably served as substrates for homologous recombination.

Polymorphism for a 1.6-Mb deletion of the human Y chromosome persists through balance between recurrent mutation and haploid selection

Many human Y-chromosomal deletions are thought to severely impair reproductive fitness, which precludes their transmission to the next generation and thus ensures their rarity in the population. Here we report a 1.6-Mb deletion that persists over generations and is sufficiently common to be considered a polymorphism. We hypothesized that this deletion might affect spermatogenesis because it removes almost half of the Y chromosomes AZFc region, a gene-rich segment that is critical for sperm production. An association study established that this deletion, called gr/gr, is a significant risk factor for spermatogenic failure. The gr/gr deletion has far lower penetrance with respect to spermatogenic failure than previously characterized Y-chromosomal deletions; it is often transmitted from father to son. By studying the distribution of gr/gr-deleted chromosomes across the branches of the Y chromosomes genealogical tree, we determined that this deletion arose independently at least 14 times in human history. We suggest that the existence of this deletion as a polymorphism reflects a balance between haploid selection, which culls gr/gr-deleted Y chromosomes from the population, and homologous recombination, which continues to generate new gr/gr deletions.

An azoospermic man with a de novo point mutation in the Y-chromosomal gene USP9Y

In humans, deletion of any one of three Y-chromosomal regions—AZFa, AZFb or AZFc—disrupts spermatogenesis, causing infertility in otherwise healthy men. Although candidate genes have been identified in all three regions, no case of spermatogenic failure has been traced to a point mutation in a Y-linked gene, or to a deletion of a single Y-linked gene. We sequenced the AZFa region of the Y chromosome and identified two functional genes previously described: USP9Y (also known as DFFRY) and DBY (refs 7,8). Screening of the two genes in 576 infertile and 96 fertile men revealed several sequence variants, most of which appear to be heritable and of little functional consequence. We found one de novo mutation in USP9Y: a 4-bp deletion in a splice-donor site, causing an exon to be skipped and protein truncation. This mutation was present in a man with nonobstructive azoospermia (that is, no sperm was detected in semen), but absent in his fertile brother, suggesting that the USP9Y mutation caused spermatogenic failure. We also identified a single-gene deletion associated with spermatogenic failure, again involving USP9Y, by re-analysing a published study.

Presence of mature sperm in testicular parenchyma of men with nonobstructive azoospermia: Prevalence and predictive factors

OBJECTIVES Hitherto, patients with testicular dysfunction and azoospermia had to resort to adoption, donor sperm insemination, or child-free living. The realization that a proportion of such men harbor spermatozoa in their testicular parenchyma, combined with the ability of intracytoplasmic sperm injection (ICSI) to effect pregnancy with single sperm, has prompted male infertility clinicians to explore testicular sperm extraction (TESE) in this patient population. We sought to investigate the likelihood of finding spermatozoa during TESE from men presenting with nonobstructive azoospermia and to define if any factors existed that were predictive of eventual sperm presence or absence. METHODS Thirty patients with nonobstructive azoospermia underwent TESE and simultaneous formal testis biopsy, cytologic analysis, and wet preparation analysis. Tissue obtained from TESE was analyzed according to a rigorous protocol, followed by exhaustive searching by trained embryologists. RESULTS Twenty-one patients (70%) had spermatozoa found on testicular tissue analysis. Neither patient age nor follicle-stimulating hormone (FSH) level was predictive of the ability to find sperm. With regard to histologic pattern, 50% of men with Sertoli cell-only, 75% of patients with maturation arrest, and 100% of patients with spermatids seen on histologic analysis had sperm retrieved from their testicular tissue during TESE. Absence of sperm on cytologic smear and wet preparation analysis failed to predict the presence of sperm on formal testicular tissue analysis in 40% of patients. CONCLUSIONS Men with nonobstructive azoospermia may have mature spermatozoa present within their testicular parenchyma. Relying on these data, patients should not be excluded from TESE based on serum FSH level, age, prior histopathologic pattern, or cytology/wet preparation results. These figures will allow clinicians to counsel patients with nonobstructive azoospermia informatively regarding TESE and their chances of having testicular sperm retrieved.

Vibratory Stimulation and Rectal Probe Electroejaculation as Therapy for Patients with Spinal Cord Injury: Semen Parameters and Pregnancy Rates

PURPOSE The conception rate of patients with spinal cord injuries following penile vibratory stimulation and rectal probe electroejaculation in conjunction with self-insemination, intrauterine insemination or assisted reproductive technique is poorly documented. We reviewed our success rates with penile vibratory stimulation and rectal probe electroejaculation, and the pregnancy rates achieved with self-insemination, intrauterine insemination and assisted reproductive techniques. MATERIALS AND METHODS A total of 78 consecutive patients with spinal cord injuries had a complete neurological examination and was treated initially with penile vibratory stimulation. If unsuccessful, rectal probe electroejaculation was performed to obtain an ejaculate. The ejaculate was then used with self-insemination, intrauterine insemination or assisted reproductive techniques and pregnancies were monitored. RESULTS Vibratory stimulation was successful in 20 of 37 patients (54%) with a cervical lesion, 14 of 26 (54%) with a lesion at or above T10 and none of 15 when the lesion was below T10. All patients except 2 who elected followup rectal probe electroejaculation had antegrade or retrograde ejaculate. Six patients (7.7%) with extremely poor semen quality were not candidates for assisted fertilization. Of 27 couples who attempted conception 17 were successful (5 self-insemination, 5 intrauterine insemination and 7 assisted reproductive techniques). CONCLUSIONS Penile vibratory stimulation should be used as first line therapy in patients with lesions above T10 while rectal probe electroejaculation should be considered as a second option. Motivated patients can achieve success with self-insemination, intrauterine insemination and assisted reproductive techniques.

Granulomatous Prostatitis Following Bacillus Calmette-Guerin Immunotherapy of Bladder Cancer

Granulomatous prostatitis is a recognized complication of intravesical bacillus Calmette-Guerin immunotherapy of superficial bladder cancer. Of 32 patients receiving such therapy 13 underwent prostatic core biopsy and/or fine needle aspiration for clinical indications. Prostatic induration or nodularity developed in 12 patients and 1 underwent biopsy for staging of known prostatic carcinoma. Granulomatous prostatitis was found in 100 per cent of those patients who underwent biopsy or aspiration, indicating that the incidence of this finding is at least 41 per cent following bacillus Calmette-Guerin immunotherapy. Acid-fast bacilli were demonstrated within the prostate of 3 patients with granulomatous prostatitis. The mean interval between the initiation of therapy and diagnosis of granulomatous prostatitis was 11.5 months. Bacillus Calmette-Guerin related granulomas of the prostate may be differentiated histologically from nonspecific granulomatous prostatitis, allergic prostatitis and postoperative granulomas. The clinical implications of these findings are discussed.

Testicular tissue extraction in a young male with 47,XXY klinefelter’s syndrome: potential strategy for preservation of fertility

OBJECTIVE To describe a case involving the cryopreservation of testis tissue retrieved from a 15-year-old male teenager with Klinefelters syndrome. DESIGN Case report. SETTING An academic medical center. PATIENT(S) A 15-year-old boy with Klinefelters syndrome. INTERVENTION(S) Microsurgical testis sperm extraction with cryopreservation of harvested tissue. MAIN OUTCOME MEASURE(S) Spermatozoa within testis tissue. RESULT(S) Successful extraction and cryopreservation of three vials of sperm-containing testis tissue. No effect on subsequent testosterone levels. CONCLUSION(S) Testis tissue extraction in the adequately virilized but azoospermic young male with 47, XXY Klinefelters syndrome may be a strategy to preserve future biological paternity.

TEX11 is mutated in infertile men with azoospermia and regulates genome-wide recombination rates in mouse

Genome‐wide recombination is essential for genome stability, evolution, and speciation. Mouse Tex11, an X‐linked meiosis‐specific gene, promotes meiotic recombination and chromosomal synapsis. Here, we report that TEX11 is mutated in infertile men with non‐obstructive azoospermia and that an analogous mutation in the mouse impairs meiosis. Genetic screening of a large cohort of idiopathic infertile men reveals that TEX11 mutations, including frameshift and splicing acceptor site mutations, cause infertility in 1% of azoospermic men. Functional evaluation of three analogous human TEX11 missense mutations in transgenic mouse models identified one mutation (V748A) as a potential infertility allele and found two mutations non‐causative. In the mouse model, an intronless autosomal Tex11 transgene functionally substitutes for the X‐linked Tex11 gene, providing genetic evidence for the X‐to‐autosomal retrotransposition evolution phenomenon. Furthermore, we find that TEX11 protein levels modulate genome‐wide recombination rates in both sexes. These studies indicate that TEX11 alleles affecting expression level or substituting single amino acids may contribute to variations in recombination rates between sexes and among individuals in humans.

Unilateral Absence of the Scrotal vas deferens Associated with Contralateral Mesonephric duct Anomalies Resulting in Infertility: Laboratory, Physical and Radiographic findings, and Therapeutic Alternatives

Ten patients who presented for infertility had unilateral absence of the scrotal vas deferens and a contralateral mesonephric duct anomaly, including contralateral ejaculatory duct or epididymal/vasal obstruction. The details of the physical examination, semen analysis and transrectal ultrasound led to an accurate preoperative diagnosis in each case. Therapeutic manipulations appropriate in this group included transurethral resection of the ejaculatory duct, microscopic vasoepididymostomy and microsurgical sperm aspiration coupled with in vitro fertilization. Only 3 patients had ipsilateral renal agenesis or ectopia (30%), which is well below the stated percentage for patients with unilateral vasal agenesis (90%). An aberration in the proper sequence of mesonephric embryological development may partly explain this bilateral constellation of abnormalities.

Results in the United States with Sperm Micro-Aspiration Retrieval Techniques and Assisted Reproductive Technologies

AbstractImproved methods of urological microsurgery and of various assisted reproductive technologies have resulted in the ability to achieve pregnancies with sperm aspirated microsurgically from men with bilateral congenital absence of the vasa deferentia or with ductal obstructions that cannot be surgically reconstructed. A survey was conducted of the results of such procedures performed in the United States during approximately 2 years. Female partner ovarian stimulation was initiated in 219 instances at 22 centers. Of the 219 procedures 23 (11%) were terminated without attempting any form of gamete fertilization or insemination of the wife for various reasons (no sperm or too few sperm retrieved, poor to absent sperm motility or poor quality eggs). The etiology of azoospermia in the 219 procedures was congenital absence of the vasa deferentia in 115 cases (52%), other congenital conditions in 15 (7%), failed vasectomy reversal in 37 (17%), infection in 4 (2%), other conditions (mainly ejaculatory dysf...