A homozygous hypomorphic BRCA2 variant causes primary ovarian insufficiency without cancer or Fanconi anemia traits

ABSTRACTPrimary Ovarian insufficiency (POI) affects 1% of women under forty. We studied a patient with a non-syndromic POI, from a consanguineous Turkish family. Exome sequencing identified a homozygous missense variant c.8524C>T/p.R2842C in BRCA2. BRCA2 is a major player in homologous recombination (HR). BRCA2 deficiency induces cancer predisposition and Fanconi Anemia (FA). Remarkably, neither the patient nor her family exhibit somatic pathologies. The patient’s somatic cells presented intermediate levels of chromosomal breaks, cell proliferation and radiation-induced RAD51 foci formation when compared to controls, the heterozygous mother’s and FA cells. R2842C-BRCA2 partially complemented BRCA2 depletion for double-strand break-induced HR. The residual HR function in patient’s cells could explain the absence of somatic pathology. BRCA2 is expressed in human fetal ovaries in pachytene stage oocytes, when meiotic HR occurs. This study has a major impact on the understanding of genome maintenance in somatic and meiotic cells and on the management of POI patients.

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Homozygous hypomorphic BRCA2 variant in primary ovarian insufficiency without cancer or Fanconi anaemia trait

Journal of Medical Genetics ◽

10.1136/jmedgenet-2019-106672 ◽

2020 ◽

pp. jmedgenet-2019-106672 ◽

Cited By ~ 2

Author(s):

Sandrine Caburet ◽

Abdelkader Heddar ◽

Elodie Dardillac ◽

Héléne Creux ◽

Marie Lambert ◽

...

Keyword(s):

Cell Proliferation ◽

Public Health Problem ◽

Chromosome Breakage ◽

Primary Ovarian Insufficiency ◽

Fanconi Anaemia ◽

Ovarian Insufficiency ◽

Her Family ◽

Functional Studies ◽

Chromosomal Breaks ◽

Radiation Induced

BackgroundPrimary ovarian insufficiency (POI) affects 1% of women under 40 years and is a public health problem. The genetic causes of POI are highly heterogeneous with isolated or syndromic forms. Recently, variants in genes involved in DNA repair have been shown to cause POI. Notably, syndromic POI with Fanconi anaemia (FA) traits related to biallelic BRCA2 truncated variants has been reported. Here, we report a novel phenotype of isolated POI with a BRCA2 variant in a consanguineous Turkish family.MethodsExome sequencing (ES) was performed in the patient. We also performed functional studies, including a homologous recombination (HR) test, cell proliferation, radiation-induced RAD51 foci formation assays and chromosome breakage studies in primary and lymphoblastoid immortalised cells. The expression of BRCA2 in human foetal ovaries was studied.ResultsES identified a homozygous missense c.8524C>T/p.R2842C-BRCA2 variant. BRCA2 defects induce cancer predisposition and FA. Remarkably, neither the patient nor her family exhibited somatic pathologies. The patient’s cells showed intermediate levels of chromosomal breaks, cell proliferation and radiation-induced RAD51 foci formation compared with controls and FA cells. R2842C-BRCA2 only partially complemented HR efficiency compared with wild type-BRCA2. BRCA2 is expressed in human foetal ovaries in pachytene stage oocytes, when meiotic HR occurs.ConclusionWe describe the functional assessment of a homozygous hypomorphic BRCA2 variant in a patient with POI without cancer or FA trait. Our findings extend the phenotype of BRCA2 biallelic alterations to fully isolated POI. This study has a major impact on the management and genetic counselling of patients with POI.

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Radiation-Induced Chromosomal Breaks may be DNA Repair Fragile Sites with Larger-scale Correlations to Eight Double-Strand-Break Related Data Sets over the Human Genome

Radiation Research ◽

10.1667/rr15424.1 ◽

2019 ◽

Vol 192 (5) ◽

pp. 562

Author(s):

Anders Brahme ◽

Maj Hultén ◽

Carin Bengtsson ◽

Andreas Hultgren ◽

Anders Zetterberg

Keyword(s):

Dna Repair ◽

Human Genome ◽

Strand Break ◽

Double Strand Break ◽

Fragile Sites ◽

Data Sets ◽

Related Data ◽

Chromosomal Breaks ◽

Radiation Induced

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A missense in HSF2BP causing Primary Ovarian Insufficiency affects meiotic recombination by its novel interactor C19ORF57/MIDAP

10.1101/2020.03.05.978007 ◽

2020 ◽

Cited By ~ 1

Author(s):

Natalia Felipe-Medina ◽

Sandrine Caburet ◽

Fernando Sánchez-Sáez ◽

Yazmine B. Condezo ◽

Dirk de Rooij ◽

...

Keyword(s):

Missense Variant ◽

Primary Ovarian Insufficiency ◽

Dna Breaks ◽

Ovarian Insufficiency ◽

Knock Out ◽

Recombination Nodules ◽

Meiotic Gene ◽

Double Strand Dna Breaks ◽

Gene Functional Analysis

AbstractPrimary Ovarian Insufficiency (POI) is a major cause of infertility, but its etiology remains poorly understood. Using whole-exome sequencing in a family with 3 cases of POI, we identified the candidate missense variant S167L in HSF2BP, an essential meiotic gene. Functional analysis of the HSF2BP-S167L variant in mouse, compared to a new HSF2BP knock-out mouse showed that it behaves as a hypomorphic allele. HSF2BP-S167L females show reduced fertility with small litter sizes. To obtain mechanistic insights, we identified C19ORF57/MIDAP as a strong interactor and stabilizer of HSF2BP by forming a higher-order macromolecular structure involving BRCA2, RAD51, RPA and PALB2. Meiocytes bearing the HSF2BP-S167L mutation showed a strongly decreased expression of both MIDAP and HSF2BP at the recombination nodules. Although HSF2BP-S167L does not affect heterodimerization between HSF2BP and MIDAP, it promotes a lower expression of both proteins and a less proficient activity in replacing RPA by the recombinases RAD51/DMC1, thus leading to a lower frequency of cross-overs. Our results provide insights into the molecular mechanism of two novel actors of meiosis underlying non-syndromic ovarian insufficiency.SummaryFelipe-Medina et al. describe a missense variant in the meiotic gene HSF2BP in a consanguineous family with Premature Ovarian Insufficiency, and characterize it as an hypormorphic allele, that in vivo impairs its dimerization with a novel meiotic actor, MIDAP/ C19ORF57, and affect recombination at double-strand DNA breaks.

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Primary Ovarian Insufficiency and Azoospermia in Carriers of a Homozygous PSMC3IP Stop Gain Mutation

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2017-01966 ◽

2017 ◽

Vol 103 (2) ◽

pp. 555-563 ◽

Cited By ~ 12

Author(s):

Abdulmoein Eid Al-Agha ◽

Ihab Abdulhamed Ahmed ◽

Esther Nuebel ◽

Mika Moriwaki ◽

Barry Moore ◽

...

Keyword(s):

Protein Localization ◽

Pubertal Development ◽

Recessive Gene ◽

Missense Variant ◽

Primary Ovarian Insufficiency ◽

Delayed Puberty ◽

Primary Amenorrhea ◽

Ovarian Insufficiency ◽

Functional Studies ◽

Exon 1

Abstract Context The etiology of primary ovarian insufficiency (POI) remains unknown in most cases. Objective We sought to identify the genes causing POI. Design The study was a familial genetic study. Setting The study was performed at two academic institutions. Patients We identified a consanguineous Yemeni family in which four daughters had POI. A brother had azoospermia. Intervention DNA was subjected to whole genome sequencing. Shared regions of homozygosity were identified using Truploidy and prioritized using the Variant Annotation, Analysis, and Search Tool with control data from 387 healthy subjects. Imaging and quantification of protein localization and mitochondrial function were examined in cell lines. Main Outcome Homozygous recessive gene variants shared by the four sisters. Results The sisters shared a homozygous stop gain mutation in exon 6 of PSMC3IP (c.489 C>G, p.Tyr163Ter) and a missense variant in exon 1 of CLPP (c.100C>T, p.Pro34Ser). The affected brother also carried the homozygous PSMC3IP mutation. Functional studies demonstrated mitochondrial fragmentation in cells infected with the CLPP mutation. However, no abnormality was found in mitochondrial targeting or respiration. Conclusions The PSMC3IP mutation provides additional evidence that mutations in meiotic homologous recombination and DNA repair genes result in distinct female and male reproductive phenotypes, including delayed puberty and primary amenorrhea caused by POI (XX gonadal dysgenesis) in females but isolated azoospermia with normal pubertal development in males. The findings also suggest that the N-terminal missense mutation in CLPP does not cause substantial mitochondrial dysfunction or contribute to ovarian insufficiency in an oligogenic manner.

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A Novel Phenotype Combining Primary Ovarian Insufficiency Growth Retardation and Pilomatricomas With MCM8 Mutation

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgaa155 ◽

2020 ◽

Vol 105 (6) ◽

pp. 1973-1982 ◽

Cited By ~ 1

Author(s):

Abdelkader Heddar ◽

Dominique Beckers ◽

Baptiste Fouquet ◽

Dominique Roland ◽

Micheline Misrahi

Keyword(s):

Growth Retardation ◽

Genetic Defect ◽

Postnatal Growth ◽

Primary Ovarian Insufficiency ◽

Primary Amenorrhea ◽

Dna Breaks ◽

Ovarian Insufficiency ◽

Messenger Ribonucleic Acid ◽

Adverse Health Outcomes ◽

Chromosomal Breaks

Abstract Context Primary Ovarian insufficiency (POI) affects 1% of women aged <40 years and leads most often to definitive infertility with adverse health outcomes. Very recently, genes involved in deoxyribonucleic acid (DNA) repair have been shown to cause POI. Objective To identify the cause of a familial POI in a consanguineous Turkish family. Design Exome sequencing was performed in the proposita and her mother. Chromosomal breaks were studied in lymphoblastoid cell lines treated with mitomycin (MMC). Setting and patients The proposita presented intrauterine and postnatal growth retardation, multiple pilomatricomas in childhood, and primary amenorrhea. She was treated with growth hormone (GH) from age 14 to 18 years. Results We identified a novel nonsense variant in exon 9 of the minichromosome maintenance complex component 8 gene (MCM8) NM_001281522.1: c0.925C > T/p.R309* yielding either a truncated protein or nonsense-mediated messenger ribonucleic acid decay. The variant was homozygous in the daughter and heterozygous in the mother. MMC induced DNA breaks and aberrant metaphases in the patient’s lymphoblastoid cells. The mother’s cells had intermediate but significantly higher chromosomal breaks compared with a control. Conclusion We describe a novel phenotype of syndromic POI related to a novel truncating MCM8 variant. We show for the first time that spontaneous tumors (pilomatricomas) are associated with an MCM8 genetic defect, making the screening of this gene necessary before starting GH therapy in patients with POI with short stature, especially in a familial or consanguineous context. Appropriate familial monitoring in the long term is necessary, and fertility preservation should be considered in heterozygous siblings to avoid rapid follicular atresia.

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Primary Ovarian Insufficiency Induced by Fanconi Anemia E Mutation in a Mouse Model

PLoS ONE ◽

10.1371/journal.pone.0144285 ◽

2016 ◽

Vol 11 (3) ◽

pp. e0144285 ◽

Cited By ~ 5

Author(s):

Chun Fu ◽

Khurshida Begum ◽

Paul A. Overbeek

Keyword(s):

Mouse Model ◽

Fanconi Anemia ◽

Primary Ovarian Insufficiency ◽

Ovarian Insufficiency

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A missense in HSF2BP causing primary ovarian insufficiency affects meiotic recombination by its novel interactor C19ORF57/BRME1

eLife ◽

10.7554/elife.56996 ◽

2020 ◽

Vol 9 ◽

Author(s):

Natalia Felipe-Medina ◽

Sandrine Caburet ◽

Fernando Sánchez-Sáez ◽

Yazmine B Condezo ◽

Dirk G de Rooij ◽

...

Keyword(s):

Missense Variant ◽

Primary Ovarian Insufficiency ◽

Loss Of Function ◽

Ovarian Insufficiency ◽

Knock Out ◽

Recombination Nodules ◽

Hypomorphic Allele ◽

Whole Exome ◽

Gene Functional Analysis ◽

Knock Out Mouse

Primary Ovarian Insufficiency (POI) is a major cause of infertility, but its etiology remains poorly understood. Using whole-exome sequencing in a family with three cases of POI, we identified the candidate missense variant S167L in HSF2BP, an essential meiotic gene. Functional analysis of the HSF2BP-S167L variant in mouse showed that it behaves as a hypomorphic allele compared to a new loss-of-function (knock-out) mouse model. Hsf2bpS167L/S167L females show reduced fertility with smaller litter sizes. To obtain mechanistic insights, we identified C19ORF57/BRME1 as a strong interactor and stabilizer of HSF2BP and showed that the BRME1/HSF2BP protein complex co-immunoprecipitates with BRCA2, RAD51, RPA and PALB2. Meiocytes bearing the HSF2BP-S167L variant showed a strongly decreased staining of both HSF2BP and BRME1 at the recombination nodules and a reduced number of the foci formed by the recombinases RAD51/DMC1, thus leading to a lower frequency of crossovers. Our results provide insights into the molecular mechanism of HSF2BP-S167L in human ovarian insufficiency and sub(in)fertility.

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Genetics of Menopause and Primary Ovarian Insufficiency: Time for a Paradigm Shift?

Seminars in Reproductive Medicine ◽

10.1055/s-0040-1721796 ◽

2020 ◽

Vol 38 (04/05) ◽

pp. 256-262

Author(s):

Joop S. E. Laven

Keyword(s):

Dna Damage ◽

Paradigm Shift ◽

Ovarian Function ◽

Excision Repair ◽

Strand Break ◽

Primary Ovarian Insufficiency ◽

Cell Renewal ◽

Ovarian Insufficiency ◽

Germ Cell Line ◽

Cell Energy

AbstractThis review summarizes the existing information concerning the genetic background of menopause and primary ovarian insufficiency (POI). There is overwhelming evidence that majority of genes are involved in double-strand break repair, mismatch repair, and base excision repair. The remaining loci were involved in cell energy metabolism and immune response. Gradual (or in case of rapid POI) accumulation of unrepaired DNA damage causes (premature) cell death and cellular senescence. This in turn leads to exhaustion of cell renewal capacity and cellular dysfunction in affected organs and eventually to aging of the entire soma. Similar erosion of the genome occurs within the germ cell line and the ovaries. Subsequently, the systemic “survival” response intentionally suppresses the sex-steroid hormonal output, which in turn may contribute to the onset of menopause. The latter occurs in particular when age-dependent DNA damage accumulation does not cease. Both effects are expected to synergize to promote (premature) ovarian silencing and install (early) menopause. Consequently, aging of the soma seems to be a primary driver for the loss of ovarian function in women. This challenges the current dogma which implies that loss of ovarian function initiates aging of the soma. It is time for a paradigm shift!

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