Species: mouse
Mutation name: None
type: null mutation
fertility: infertile - ovarian defect
Comment: Rajkovic A, et al reported that NOBOX deficiency disrupts early folliculogenesis and oocyte-specific gene expression. Primordial ovarian follicles in mice form when somatic cells surround individual oocytes. The authors show that lack of Nobox, an oocyte-specific homeobox gene, accelerates postnatal oocyte loss and abolishes the transition from primordial to growing follicles in mice. Follicles are replaced by fibrous tissue in female mice lacking Nobox in a manner similar to nonsyndromic ovarian failure in women. Genes preferentially expressed in oocytes, including Oct4 and Gdf9, are down-regulated in Nobox-/- mice, whereas ubiquitous genes such as Bmp4, Kit, and Bax remain unaffected. Therefore, Nobox is critical for specifying an oocyte-restricted gene expression pattern essential for postnatal follicle development. Premature ovarian failure in nobox-deficient mice is caused by defects in somatic cell invasion and germ cell cyst breakdown. Lechowska A et al. PURPOSE: To understand the mechanism of premature ovarian failure (POF). METHODS: The ultrastructural (electron microscopy) analysis of primordial ovarian follicles in Nobox deficient mice. RESULTS: We studied, for the first time, the fate of oogonia in embryonic (prenatal) mouse ovaries and showed that the abolishment of the transition from germ cell cysts to primordial follicles in the ovaries of Nobox deficient mice is caused by defects in germ cell cyst breakdown, leading to the formation of syncytial follicles instead of primordial follicles. CONCLUSIONS: These results indicate that POF syndrome in Nobox deficient mice results from the faulty signaling between somatic and germ line components during embryonic development. In addition, the extremely unusual and abnormal presence of adherens junctions between unseparated oocytes within syncytial follicles indicates that faulty communication between somatic and germ cells is involved in, or leads to, abnormalities in the cell adhesion program.

Species: human
Mutation name: None
type: naturally occurring
fertility: subfertile
Comment: NOBOX Homeobox Mutation Causes Premature Ovarian Failure. Qin Y et al. NOBOX (newborn ovary homeobox gene) is an oocyte-specific homeobox gene that plays a critical role in early folliculogenesis and represents a candidate gene for nonsyndromic ovarian failure. We investigated whether mutations in the NOBOX gene cause premature ovarian failure (POF). We sequenced the NOBOX gene in 96 white women with POF and discovered seven known single-nucleotide polymorphisms and four novel variations, two of which, p.Arg355His and p.Arg360Gln, cause missense mutations in the homeobox domain. Electrophoretic mobility shift assay (EMSA) confirmed that the missense mutation, p.Arg355His, disrupted NOBOX homeodomain binding to NOBOX DNA-binding element (NBE) and had a dominant negative effect on the binding of wild-type NOBOX to DNA. Our findings demonstrate that NOBOX mutations can cause POF.

Species: human
Mutation name: None
type: naturally occurring
fertility: subfertile
Comment: Novel NOBOX loss-of-function mutations account for 6.2% of cases in a large primary ovarian insufficiency cohort. Bouilly J et al. Primary ovarian insufficiency (POI) is a disorder associated with female infertility, which affects approximately 1% of women under 40 years of age. A genetic component has been suggested as one possible cause of the majority of cases of nonsyndromic forms. NOBOX (Newborn Ovary Homeobox) is an ovary-specific gene, playing a critical role in ovary in mice, as its absence leads to sterility mimicking a POI. In this study, we sequenced NOBOX in a cohort of 178 women with idiopathic POI. Among 19 identified variations, we described one nonsense (c.907C>T/p.R303X) and four missense (c.271G>T/p.G91W, c.349C>T/p.R117W, c.1025G>C/p.S342T and c.1048G>T/p.V350L) NOBOX heterozygous mutations in 12 patients. We reproduced each of the five mutations, and tested their effects on the signalling activity in transfected cells. We demonstrated that these mutations compromised the ability of the proteins to bind to and transactivate the well known growth-differentiation factor 9 (GDF9) promoter. The pattern of our findings suggests that the genetic mechanism in humans responsible for POI in women involves haploinsufficiency rather than dominant negative gene action. The identification, characterization and the very high 6.2% prevalence of these new mutations in POI patients suggest considering NOBOX as the first autosomal candidate gene involved in this syndrome. ?2011 Wiley-Liss, Inc. Mutation analysis of NOBOX homeodomain in chinese women with premature ovarian failure. Qin Y et al. The newborn ovary homeobox gene (NOBOX) is an oocyte-specific homeobox gene that plays a critical role in early folliculogenesis, thus representing an attractive candidate gene for nonsyndromic ovarian failure. We investigated whether perturbation in the homeodomain region of NOBOX was present in Chinese women with premature ovarian failure (POF). We sequenced 200 Chinese patients with POF, and discovered only two known single nucleotide polymorphisms: in intron 6 (c.1154+11 T>C and c.1155-22 G>A); neither offers plausible explanations for POF. Failing to find causative mutation contrasts with our previous study in a caucasian sample, in which we found plausible homeobox mutation in 1 of 96 POF cases. Mutations in the homeobox domain of NOBOX are not common explanations for POF in Chinese women.

Species: human
Mutation name:
type: naturally occurring
fertility: subfertile
Comment: Impaired protein stability and nuclear localization of NOBOX variants associated with Premature Ovarian Insufficiency. Ferrari I et al. (2016) Premature Ovarian Insufficiency (POI) is a clinical syndrome defined by a loss of ovarian activity before the age of 40. Its pathogenesis is still largely unknown, but increasing evidences support a genetic basis in most cases. Among these, heterozygous mutations in NOBOX, a homeobox gene encoding a transcription factor expressed specifically by oocyte and granulosa cells within the ovary, have been reported in ~ 6 % of women with sporadic POI. The pivotal role of NOBOX in early folliculogenesis is supported by findings in knock-out mice. Here, we report the genetic screening of 107 European women with idiopathic POI, recruited in various settings, and the molecular and functional characterization of the identified variants in order to evaluate their involvement in POI onset. Specifically, we report the identification of 2 novel and 2 recurrent heterozygous NOBOX variants in 7 out of 107 patients, with a prevalence of 6.5% (upper 95% confidence limit of 11.17%). Furthermore, immunolocalization, Western Blot and transcriptional assays conducted in either HEK293T or CHO cells revealed that all the studied variants (p.R44L, p.G91W, p.G111R, p.G152R, p.K273*, p.R449* and p.D452N) display variable degrees of functional impairment, including defects in transcriptional activity, autophagosomal degradation, nuclear localization or protein instability. Several variants conserve the ability to interact with FOXL2 in intracellular aggregates. Their inability to sustain gene expression, together with their likely aberrant effects on protein stability and degradation, make the identified NOBOX mutations a plausible cause of POI onset.//////////////////

Species: human
Mutation name:
type: naturally occurring
fertility: subfertile
Comment: A homozygous NOBOX truncating variant causes defective transcriptional activation and leads to primary ovarian insufficiency. Li L et al. (2016) Does a novel homozygous NOBOX truncating variant, identified in whole exome sequencing (WES) of patients with primary ovarian insufficiency (POI), cause defective transcriptional activation of multiple oocyte-related genes? A novel homozygous truncating mutation of NOBOX was confirmed to exhibit a loss-of-function effect using well-defined molecular and functional analyses. Several NOBOX mutations have been reported to be associated with POI but all of them are heterozygous mutations. This is a cross sectional study in 96 patients diagnosed with POI and 211 women not diagnosed with POI in China. Blood samples collected from the participants were subjected to whole exome sequencing. Full-length transcript of NOBOX was cloned directly from human fetal ovary (FO). Functional analysis was performed for a NOBOX sequence variant associated with POI. One novel homozygous truncating variant, chr7:144098161delC, in the NOBOX gene was found in a POI patient. The truncating variant showed a severe defect in transcriptional activation of GDF9 a well-known target NOBOX. Furthermore, using real-time quantitative PCR analysis, we found many oocyte-related genes were expressed at lower level in truncating variant cells than in control cells. In addition, we found that the truncated NOBOX lost its ability to induce the G2/M arrest.Notably, our results confirmed that the 1725 bp NOBOX transcript is expressed in human FO and is the only functional isoform in transcriptional activation assays. Although the in vitro assays demonstrated the loss-of-function effect of truncating mutation on NOBOX transcriptional activation, further studies are needed to validate its long-term effects on folliculogenesis and POI. This is the first homozygous mutation of NOBOX associated with POI showing a loss-of-function effect using well-defined molecular and functional analyses. These results will aid both researchers and clinicians in understanding the molecular pathology of NOBOX and POI to develop diagnostic assays or therapeutic approaches. Research funding is provided by the Ministry of Science and Technology of China [2012CB944704; 2012CB966702], the National Natural Science Foundation of China [Grant number: 31171429] and Beijing Advanced Innovation Center for Structural Biology. The authors declare no conflict of interest.//////////////////

Species: human
Mutation name:
type: None
fertility: None
Comment: Bouilly et al. (2016) : Idiopathic primary ovarian insufficiency (POI) is a major cause of amenorrhea and infertility. POI affects1%ofwomenbefore age 40 years, and several genetic causes have been reported. To date, POI has been considered a monogenic disorder. Objective: The aim of this study was to identify novel gene variations and to investigate if individuals with POI harbor mutation in multiple loci. Patients and Methods: One hundred well-phenotyped POI patients were systematically screened for variants in 19 known POI loci (and potential candidate genes) using next-generation sequencing. Results: At least one rare protein-altering gene variant was identified in 19 patients, including missense mutations in new candidate genes, namely SMC1 and REC8 (involved in the cohesin complex) and LHX8, a gene encoding a transcription factor. Novel or recurrent deleterious mutations were also detected in the known POI candidate genes NOBOX, FOXL2, SOHLH1, FIGLA, GDF9, BMP15, and GALT. Seven patients harbor mutations in two loci, and this digenicity seems to influence the age of symptom onset. Conclusions: Genetic anomalies in women with POI are more frequent than previously believed. Digenic findings in several cases suggest that POI is not a purely monogenic disorder and points to a role of digenicity. The genotype-phenotype correlations in some kindreds suggest that a synergistic effect of several mutations may underlie the POI phenotype. (J Clin Endocrinol Metab 101: 4541–4550, 2016)