A MEI1 homozygous missense mutation associated with meiotic arrest in a consanguineous family.

Although meiotic arrest in males is observed in about 25% of azoospermic patients, pure homogeneous arrest in all seminiferous tubules is less frequent, and may be due to mutation of a single gene. However, given the large number of genes involved in meiosis, this gives rises to extensive genetic heterogeneity. Only two genetic abnormalities have been reported on a regular basis: the X-linked exonic TEX11 deletion, and the AZFb microdeletion on the Y chromosome. Other single gene defects were private and found in consanguineous families. Here, we report on a homozygous missense mutation in the gene coding for meiotic double-stranded break formation protein 1 (MEI1; c.C3307T:p.R1103W) observed in two brothers (from a consanguineous Tunisian family) with non-obstructive azoospermia and meiotic arrest. A fertile brother was heterozygous for the mutation. All the queried databases predicted that this mutation is damaging, and it has previously been reported that Mei1 knock-out is associated with meiotic arrest in a murine model. Hence, meiotic arrest in the two brothers was probably caused by an alteration in a gene known to be fundamental for chromosome synapsis.

Tumor necrosis factor-308 polymorphism increases the embryo implantation rate in women undergoing in vitro fertilization.

STUDY QUESTION: Do TNF-308 and -238 polymorphisms impact the embryo implantation rate after in vitro fertilization (IVF) in women without female infertility factor? SUMMARY ANSWER: The presence of the TNF-308A allele is associated with high implantation and multiple pregnancy rates in women without known infertility factors after ovarian hyperstimulation with exogenous FSH. WHAT IS ALREADY KNOWN: Multiple pregnancies are frequent after the use of Assisted Reproductive Technologies. Single embryo transfer (SET) has been proposed as a simple way to prevent these risks. However, the extension of SET indications to patients not selected based on specific criteria is controversial because of reduced pregnancy rates. To date, the predictive value of the parameters used for SET (age, gynecological history of the patient and uterine characteristics) allows a pregnancy rate of ~30%. STUDY DESIGN, SIZE, DURATION: The potential predictive value of TNF polymorphisms (-308, rs1800629 and -238, rs361525) on implantation rate was evaluated in 424 women requiring IVF due to male fertility factors. This cohort retrospective study was conducted over 4 years in University-affiliated hospitals. PARTICIPANTS, SETTING, METHODS: The entire patient group included 424 women undergoing intracytoplasmic sperm injection (ICSI) due to male fertility factors without the contribution of any female factor. From among this group, a selected patient group included 120 women with a normal karyotype, age under 38 years, serum follicle-stimulating hormone (Day-3 FSH) levels below 10 IU/l, a long agonist desensitization protocol associated with recombinant FSH treatment and a Caucasian background. MAIN RESULTS AND THE ROLE OF CHANCE: The TNF-238 polymorphism was not associated with implantation rate. In contrast, the presence of the TNF-308A allele was associated with increased Day 3-E2 levels as well as higher implantation and multiple pregnancy rates after fresh embryo transfer in women from the entire and selected patient groups. Moreover, in the selected patient group, the presence of the TNF-308A allele was also associated with a decrease in the miscarriage rate. The benefit of the TNF-308A allele in predicting implantation rates was not observed after the use of frozen embryos. LIMITATIONS, REASONS FOR CAUTION: Future studies are needed to evaluate whether the TNF-308A allele might also be a biomarker in women with infertility factors. WIDER IMPLICATIONS OF THE FINDING: The TNF-308A allele may represent a good candidate for a potential predictive, non-invasive biomarker in the SET strategy. However, its impact should be evaluated in prospective studies. STUDY FUNDING/COMPETING INTEREST: This study was conducted with financial support from the French Institute for Health and Medical Research (INSERM), Organon France for a FARO (Fond d'Aide à la Recherche Organon) fellowship (to V.T.) and CHU Nice PHRC (PHRC 09-279).There are no competing interests.

Factors related to unstained areas in whole ewe ovaries perfused with a metabolic marker.

STUDY QUESTION: What factors are associated with the presence of areas unexposed to the perfusate after whole ovary perfusion? SUMMARY ANSWER: Over half the ovaries perfused with the metabolic marker methylthiazolyl blue tetrazolium (MTT) were incompletely stained. Incomplete staining was statistically significantly associated with a small ovarian slice surface area, inexperience of the experimenter, and the presence of a corpus luteum. WHAT IS KNOWN ALREADY: Whole ovary cryopreservation followed by vascular auto-transplantation has provided poor outcomes as an alternative way to safeguard fertility. Perfusion, commonly used to expose the ovaries to cryoprotectants, may miss areas excluded from the vascular network, explaining subsequent poor ovarian functionality. STUDY DESIGN, SIZE, DURATION: An observational study of 360 ewe ovaries stained by in vitro perfusion with MTT as a qualitative marker of tissue blood supply was performed. A logistic regression model was built to identify factors associated with incomplete ovary staining. MATERIALS, SETTING, METHODS: Whole ewe ovaries with their vascular pedicles were perfused at 0.35 ml/min with 1 g/l MTT for 2 h at 39°C under 19 experimental conditions. The pedicles were removed and the ovaries cut in half sagittally and photographed. The unstained area of the slice surface was measured. Times from ovary collection to ovary rinsing and to MTT perfusion initiation, ovary weight and slice surface area, presence of a corpus luteum and operator experience (number of ovaries previously perfused) were recorded. Pedicle MTT staining was quantified at 564 nm after solubilization in alcohol. MAIN RESULTS AND THE ROLE OF CHANCE: Unstained areas were observed in 64.4% of the ovaries. Multivariate analysis found that incomplete ovary staining was independently associated with lower experimenter experience (P < 0.02), smaller ovary slice surface area (P < 0.0001) and presence of a corpus luteum (P < 0.01). The presence of unstained areas was independent from experimental conditions. The rate of incomplete ovary staining decreased from 83 to 60% beyond the 80th perfused ovary (P < 0.0001). LIMITATIONS, REASONS FOR CAUTION: Descriptive study. WIDER IMPLICATIONS OF THE FINDINGS: Blood-supply impairments that result in incomplete perfusion might adversely affect outcomes after whole ovary cryopreservation. Improved perfusion techniques should enhance success.