Species: mouse
Mutation name: None
type: null mutation
fertility: subfertile
Comment: Oogenesis requires germ cell-specific transcriptional regulators Sohlh1 and Lhx8. Pangas SA et al. Mammalian oogenesis requires oocyte-specific transcriptional regulators. The full complement of oocyte-specific transcription factors is unknown. Here, we describe the finding that Sohlh1, a spermatogenesis and oogenesis basic helix-loop-helix transcription factor in females, is preferentially expressed in oocytes and required for oogenesis. Sohlh1 disruption perturbs follicular formation in part by causing down-regulation of two genes that are known to disrupt folliculogenesis: newborn ovary homeobox gene (Nobox) and factor in the germ-line alpha (Figla). In addition, we show that Lhx8 is downstream of Sohlh1 and critical in fertility. Thus, Sohlh1 and Lhx8 are two germ cell-specific, critical regulators of oogenesis.

Species: human
Mutation name:
type: null mutation
fertility: infertile - ovarian defect
Comment: Transcription factors SOHLH1 and SOHLH2 coordinate oocyte differentiation without affecting meiosis I. Shin YH et al. (2017) Following migration of primordial germ cells to the genital ridge, oogonia undergo several rounds of mitotic division and enter meiosis at approximately E13.5. Most oocytes arrest in the dictyate (diplotene) stage of meiosis circa E18.5. The genes necessary to drive oocyte differentiation in parallel with meiosis are unknown. Here, we have investigated whether expression of spermatogenesis and oogenesis bHLH transcription factor 1 (Sohlh1) and Sohlh2 coordinates oocyte differentiation within the embryonic ovary. We found that SOHLH2 protein was expressed in the mouse germline as early as E12.5 and preceded SOHLH1 protein expression, which occurred circa E15.5. SOHLH1 protein appearance at E15.5 correlated with SOHLH2 translocation from the cytoplasm into the nucleus and was dependent on SOHLH1 expression. NOBOX oogenesis homeobox (NOBOX) and LIM homeobox protein 8 (LHX8), two important regulators of postnatal oogenesis, were coexpressed with SOHLH1. Single deficiency of Sohlh1 or Sohlh2 disrupted the expression of LHX8 and NOBOX in the embryonic gonad without affecting meiosis. Sohlh1-KO infertility was rescued by conditional expression of the Sohlh1 transgene after the onset of meiosis. However, Sohlh1 or Sohlh2 transgene expression could not rescue Sohlh2-KO infertility due to a lack of Sohlh1 or Sohlh2 expression in rescued mice. Our results indicate that Sohlh1 and Sohlh2 are essential regulators of oocyte differentiation but do not affect meiosis I.//////////////////

Species: None
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)

Species: human
Mutation name:
type: naturally occurring
fertility: subfertile
Comment: Transcription factor SOHLH1 potentially associated with primary ovarian insufficiency. Zhao S et al. (2015) To investigate whether gene variants of SOHLH1 exist in Chinese and Serbian patients with primary ovarian insufficiency (POI). Case-control genetic study. University hospitals. A total of 364 Han Chinese and 197 Serbian women with nonsyndromic POI and ethnically matched controls. None. SOHLH1 gene sequencing. We found 10 novel heterozygous variants in our cohorts of 561 women with POI but none in the 600 ethnically matched controls. Statistical and bioinformatic analyses indicated that three of the eight variants in Chinese POI cases are potentially disease causing. They comprise two missense variants (p.Ser317Phe and p.Glu376Lys) that might each change activity of the SOHLH1 protein as a transcription factor and one variant (c.*118C>T) located in the 3' untranslated region of the SOHLH1 gene, which might generate a new binding site for the microRNA hsa-miR-888-5p. Of the two variants in the Serbian POI cases, both were synonymous, and no missense variant was identified. The allele frequencies of some known single-nucleotide polymorphisms were statistically significantly different between patients and controls in both the Chinese and Serbian groups. Our results suggest that SOHLH1 may be regarded as a new candidate gene for POI.//////////////////

Species: human
Mutation name:
type: naturally occurring
fertility: subfertile
Comment: Exome Sequencing of a Primary Ovarian Insufficiency Cohort Reveals Common Molecular Etiologies for a Spectrum of Disease. Jolly A et al. (2020) Primary ovarian insufficiency (POI) encompasses a spectrum of premature menopause, including both primary and secondary amenorrhea. For 75% to 90% of individuals with hypergonadotropic hypogonadism presenting as POI, the molecular etiology is unknown. Common etiologies include chromosomal abnormalities, environmental factors, and congenital disorders affecting ovarian development and function, as well as syndromic and nonsyndromic single gene disorders suggesting POI represents a complex trait. To characterize the contribution of known disease genes to POI and identify molecular etiologies and biological underpinnings of POI. We applied exome sequencing (ES) and family-based genomics to 42 affected female individuals from 36 unrelated Turkish families, including 31 with reported parental consanguinity. This analysis identified likely damaging, potentially contributing variants and molecular diagnoses in 16 families (44%), including 11 families with likely damaging variants in known genes and five families with predicted deleterious variants in disease genes (IGSF10, MND1, MRPS22, and SOHLH1) not previously associated with POI. Of the 16 families, 2 (13%) had evidence for potentially pathogenic variants at more than one locus. Absence of heterozygosity consistent with identity-by-descent mediated recessive disease burden contributes to molecular diagnosis in 15 of 16 (94%) families. GeneMatcher allowed identification of additional families from diverse genetic backgrounds. ES analysis of a POI cohort further characterized locus heterogeneity, reaffirmed the association of genes integral to meiotic recombination, demonstrated the likely contribution of genes involved in hypothalamic development, and documented multilocus pathogenic variation suggesting the potential for oligogenic inheritance contributing to the development of POI.//////////////////