RESUMO
Mutations accumulate in the genome of every cell of the body throughout life, causing cancer and other diseases1,2. Most mutations begin as nucleotide mismatches or damage in one of the two strands of the DNA before becoming double-strand mutations if unrepaired or misrepaired3,4. However, current DNA-sequencing technologies cannot accurately resolve these initial single-strand events. Here we develop a single-molecule, long-read sequencing method (Hairpin Duplex Enhanced Fidelity sequencing (HiDEF-seq)) that achieves single-molecule fidelity for base substitutions when present in either one or both DNA strands. HiDEF-seq also detects cytosine deamination-a common type of DNA damage-with single-molecule fidelity. We profiled 134 samples from diverse tissues, including from individuals with cancer predisposition syndromes, and derive from them single-strand mismatch and damage signatures. We find correspondences between these single-strand signatures and known double-strand mutational signatures, which resolves the identity of the initiating lesions. Tumours deficient in both mismatch repair and replicative polymerase proofreading show distinct single-strand mismatch patterns compared to samples that are deficient in only polymerase proofreading. We also define a single-strand damage signature for APOBEC3A. In the mitochondrial genome, our findings support a mutagenic mechanism occurring primarily during replication. As double-strand DNA mutations are only the end point of the mutation process, our approach to detect the initiating single-strand events at single-molecule resolution will enable studies of how mutations arise in a variety of contexts, especially in cancer and ageing.
Assuntos
Pareamento Incorreto de Bases , Dano ao DNA , DNA de Cadeia Simples , Análise de Sequência de DNA , Imagem Individual de Molécula , Humanos , Envelhecimento/genética , Desaminases APOBEC/genética , Desaminases APOBEC/metabolismo , Pareamento Incorreto de Bases/genética , Citidina Desaminase/metabolismo , Citidina Desaminase/genética , Citosina/metabolismo , Desaminação , Dano ao DNA/genética , Reparo de Erro de Pareamento de DNA/genética , Replicação do DNA/genética , DNA de Cadeia Simples/genética , Genoma Mitocondrial/genética , Mutação , Neoplasias/genética , Análise de Sequência de DNA/métodos , Análise de Sequência de DNA/normas , Imagem Individual de Molécula/métodos , Masculino , FemininoRESUMO
BACKGROUND: Reports of dual carriers of pathogenic BRCA1 variants in trans are extremely rare, and so far, most individuals have been associated with a Fanconi Anemia-like phenotype. METHODS: We identified two families with a BRCA1 in-frame exon 20 duplication (Ex20dup). In one male individual, the variant was in trans with the BRCA1 frameshift variant c.2475delC p.(Asp825Glufs*21). We performed splicing analysis and used a transcription activation domain (TAD) assay to assess the functional impact of Ex20dup. We collected pedigrees and mapped the breakpoints of the duplication by long- and short-read genome sequencing. In addition, we performed a mitomycin C (MMC) assay from the dual carrier using cultured lymphoblastoid cells. RESULTS: Genome sequencing and RNA analysis revealed the BRCA1 exon 20 duplication to be in tandem. The duplication was expressed without skipping any one of the two exon 20 copies, resulting in a lack of wild-type transcripts from this allele. TAD assay indicated that the Ex20dup variant has a functional level similar to the well-known moderate penetrant pathogenic BRCA1 variant c.5096G > A p.(Arg1699Gln). MMC assay of the dual carrier indicated a slightly impaired chromosomal repair ability. CONCLUSIONS: This is the first reported case where two BRCA1 variants with demonstrated functional impact are identified in trans in a male patient with an apparently normal clinical phenotype and no BRCA1-associated cancer. The results pinpoint a minimum necessary BRCA1 protein activity to avoid a Fanconi Anemia-like phenotype in compound heterozygous status and yet still predispose carriers to hormone-related cancers. These findings urge caution when counseling families regarding potential Fanconi Anemia risk. Furthermore, prudence should be taken when classifying individual variants as benign based on co-occurrence in trans with well-established pathogenic variants.
Assuntos
Neoplasias da Mama , Anemia de Fanconi , Humanos , Masculino , Proteína BRCA1/genética , Éxons/genética , Anemia de Fanconi/genética , Mitomicina , FenótipoRESUMO
STUDY QUESTION: Has there been variation in semen quality among men applying to be sperm donors (i.e. donor candidates) in Denmark in recent years (2017-2022)? SUMMARY ANSWER: The motile sperm concentration and total motile sperm count (TMSC) in ejaculates-both measures of sperm quality-declined by as much as 22% from 2019 to 2022. WHAT IS KNOWN ALREADY: Questions remain about whether human semen quality has declined in recent years. Whilst some studies provide evidence for a decline in human semen quality, these findings have been disputed owing to potential biases in the populations studied or in the methods used to measure semen quality. Resolution of this issue has important implications for human fertility, as well as for those involved in the recruitment of sperm donors for use in medically assisted reproduction. STUDY DESIGN, SIZE, DURATION: We obtained data on the semen quality of ejaculates previously collected from 2017 to 2022 at sperm bank locations in four cities in Denmark: Aarhus, Aalborg, Copenhagen, and Odense. Our study focuses on the single semen samples provided by 6758 donor candidates aged between 18 and 45 years old to determine whether their sperm quality met a minimum criterion for them to be accepted as sperm donors. PARTICIPANTS/MATERIALS, SETTING, METHODS: All ejaculates were analyzed within 1 hour of production. Semen volume (ml) was estimated by weight and both the concentration (106/ml) of sperm as well as the concentration of motile sperm (World Health Organization grades a and b) were measured using the same protocols and computer-assisted semen analysis system across all years at each site. Statistical analyses of the semen variables were controlled for age and donation site, as well as the average monthly high temperature when the ejaculate was produced. MAIN RESULTS AND THE ROLE OF CHANCE: From 2017 to 2019, semen volume, sperm concentration, and total sperm count in the ejaculates of donor candidates increased by 2-12%. Then, from 2019 to 2022, sperm concentration and total sperm count changed by 0.1-5% from year to year, but none of those changes were statistically significant. In contrast, both motile sperm concentration and TMSC declined significantly, by 16% and 22%, respectively, between 2019 and 2022. Thus, the concentration of motile sperm in donor candidates declined from 18.4 [95% CL: 17.0, 20.0] million/ml in 2019 to 15.5 [14.4, 16.7] million/ml in 2022, and TMSC declined from 61.4 [55.8, 67.5] million per ejaculate in 2019 to 48.1 [44.1, 52.4] million in 2022. LIMITATIONS, REASONS FOR CAUTION: We cannot determine from the available data the causes of the decline in semen quality of donor candidates from 2019 to 2022. However, as this period coincides with lockdowns and changes in work patterns during the coronavirus disease 2019 pandemic, it is possible that changes in motile sperm concentration and TMSC were the result of changes in the lifestyles of the men whose semen was analyzed. WIDER IMPLICATIONS OF THE FINDINGS: Men providing initial semen samples at sperm banks, when applying to be sperm donors, are a useful population in which to monitor changes in human semen quality over time. Our results have implications for human fertility and the recruitment of sperm donors for medically assisted reproduction, where motile sperm concentration is an essential selection criterion because it influences fertility. We suggest that gathering health and lifestyle data on donor candidates at sperm banks might help to identify causal factors for the decline of sperm quality that could be addressed and intervention, if desired, could be personalized for each accepted donor. STUDY FUNDING/COMPETING INTEREST(S): No external funding was obtained for this study. E.L. and A.-B.S. are employees of Cryos International. AP reports paid consultancy for Cryos International, Cytoswim Ltd, Exceed Health, and Merck Serono in the last 2 years of this study, but all monies were paid to the University of Sheffield (former employer). AP is also an unpaid trustee of the Progress Educational Trust (Charity Number 1139856). RM declares support from Cryos International to present results of this research at ESHRE 2023. None of the authors were directly involved in the collection or physical analysis of semen samples. TRIAL REGISTRATION NUMBER: N/A.
Assuntos
Análise do Sêmen , Bancos de Esperma , Motilidade dos Espermatozoides , Doadores de Tecidos , Humanos , Masculino , Dinamarca , Adulto , Pessoa de Meia-Idade , Contagem de Espermatozoides , Adulto Jovem , Adolescente , Espermatozoides/fisiologiaRESUMO
STUDY QUESTION: Is the outcome of donor recruitment influenced by the country in which recruitment took place or the initial identity (ID)-release choice of applicants? SUMMARY ANSWER: More applicants are accepted as donors in Denmark than in the USA and those who choose ID release are more frequently accepted than those who do not. WHAT IS KNOWN ALREADY: The successful recruitment of sperm donors is essential to provide a range of medically assisted reproduction (MAR) procedures, which rely upon donor sperm. However, while much has been written about the medical screening and assessment of sperm donors from a safety perspective, relatively little has been written about the process of recruiting donors and how it works in practice. There are differences in demographic characteristics between donors who choose to allow their identity to be released to their donor offspring (ID release) compared to those who do not (non-ID release). These characteristics may also influence the likelihood of them being recruited. STUDY DESIGN, SIZE, DURATION: A total of 11 712 men applied to be sperm donors at a sperm bank in Denmark and the USA during 2018 and 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: Anonymized records of all donor applicants were examined to assess the number passing through (or lost) at each stage of the recruitment process. Statistical analysis was carried out to examine differences between location (Denmark or USA) and/or donor type (ID release versus non-ID release). MAIN RESULTS AND THE ROLE OF CHANCE: Few applicants (3.79%) were accepted as donors and had samples frozen and released for use; this was higher in Denmark (6.53%) than in the USA (1.03%) (χ2 = 243.2; 1 degree of freedom (df); z = 15.60; P < 0.0001) and was higher in donors who opted at the outset to be ID release (4.70%) compared to those who did not (3.15%) (χ2 = 18.51; 1 df; z = 4.303; P < 0.0001). Most candidate donors were lost during recruitment because they: withdrew, failed to respond, did not attend an appointment, or did not return a questionnaire (54.91%); reported a disqualifying health issue or failed a screening test (17.41%); did not meet the eligibility criteria at the outset (11.71%); or did not have >5 × 106 motile sperm/ml in their post-thaw samples (11.20%). At each stage, there were statistically significant differences between countries and the donor's initial ID choice. During recruitment, some donors decided to change ID type. There were no country differences in the frequency in which this occurred (χ2 = 0.2852; 1 df; z = 0.5340; P = 0.5933), but it was more common for donors to change from non-ID release to ID release (27.19%) than the other way around (11.45%) (χ2 = 17.75; 1 df; z = 4.213; P < 0.0001), although movements in both directions did occur in both countries. LIMITATIONS, REASONS FOR CAUTION: No information was available about the demographic characteristics of the applicants, which may also have influenced their chances of being accepted as a donor (e.g. ethnicity and age). Donor recruitment procedures may differ in other locations according to local laws or guidelines. WIDER IMPLICATIONS OF THE FINDINGS: A better understanding of when and why candidate donors are lost in the recruitment process may help develop leaner and more efficient pathways for interested donors and sperm banks. This could ultimately increase the number of donors recruited (through enhanced information, support, and reassurance during the recruitment process) or it may reduce the financial cost to the recipients of donor sperm, thus making it more affordable to those who are ineligible for state-funded treatment. STUDY FUNDING/COMPETING INTEREST(S): The study received no funding from external sources. All authors are Cryos employees or members of the Cryos External Scientific Advisory Committee. TRIAL REGISTRATION NUMBER: N/A.
Assuntos
Revelação , Sêmen , Humanos , Masculino , Doadores de Tecidos , Espermatozoides , DinamarcaRESUMO
BACKGROUND: Previous research has shown that the type and duration of erotic material that men have access to during masturbation can influence semen parameters. To our knowledge, the use of virtual reality (VR) headsets to present erotica has not previously been studied. We reasoned that, because VR can provide a more immersive experience to the user, semen parameters of masturbatory ejaculates may be altered. METHODS: This study had a balanced and randomized controlled cross-over within-subjects design. 504 ejaculates were collected from 63 sperm donors at 4 locations in Denmark. During masturbation each donor was instructed to observe erotic material either on a touch screen monitor or using a VR headset. The order of each pair of within-subject treatments was randomized by the throw of a dice. Anonymized data were analysed with linear mixed and piecewise structural equation models. RESULTS: Both abstinence period and VR-use influenced the total number of motile spermatozoa ejaculated. For short abstinence periods, VR-use increased the number of motile sperm in the ejaculate. However, the difference between VR and non-VR ejaculates decreased as abstinence period increased such that there was no difference at the mean abstinence period of 58 h. For longer abstinence periods, total motile sperm counts were lower, on average, when men used VR compared to those that did not. CONCLUSION: The use of VR headsets to view erotica had a strong positive effect on the number of motile sperm in an ejaculate when the donor's abstinence time was short (< 24 h). VR-use could improve the ejaculate quality of men who are asked to provide samples after a short period of abstinence, such as men in infertile partnerships producing samples for ART or cancer patients depositing sperm before treatment. TRIAL REGISTRATION: Trial retrospectively registered on 13 July 2022 at ClinicalTrials.gov. Identifier: NCT05457764.
Assuntos
Sêmen , Realidade Virtual , Ejaculação , Literatura Erótica , Humanos , Masculino , Contagem de Espermatozoides , Motilidade dos Espermatozoides , EspermatozoidesRESUMO
Multiple primary tumors (MPTs) affect a substantial proportion of cancer survivors and can result from various causes, including inherited predisposition. Currently, germline genetic testing of MPT-affected individuals for variants in cancer-predisposition genes (CPGs) is mostly targeted by tumor type. We ascertained pre-assessed MPT individuals (with at least two primary tumors by age 60 years or at least three by 70 years) from genetics centers and performed whole-genome sequencing (WGS) on 460 individuals from 440 families. Despite previous negative genetic assessment and molecular investigations, pathogenic variants in moderate- and high-risk CPGs were detected in 67/440 (15.2%) probands. WGS detected variants that would not be (or were not) detected by targeted resequencing strategies, including low-frequency structural variants (6/440 [1.4%] probands). In most individuals with a germline variant assessed as pathogenic or likely pathogenic (P/LP), at least one of their tumor types was characteristic of variants in the relevant CPG. However, in 29 probands (42.2% of those with a P/LP variant), the tumor phenotype appeared discordant. The frequency of individuals with truncating or splice-site CPG variants and at least one discordant tumor type was significantly higher than in a control population (χ2 = 43.642; p ≤ 0.0001). 2/67 (3%) probands with P/LP variants had evidence of multiple inherited neoplasia allele syndrome (MINAS) with deleterious variants in two CPGs. Together with variant detection rates from a previous series of similarly ascertained MPT-affected individuals, the present results suggest that first-line comprehensive CPG analysis in an MPT cohort referred to clinical genetics services would detect a deleterious variant in about a third of individuals.
Assuntos
Predisposição Genética para Doença/genética , Variação Genética/genética , Neoplasias Primárias Múltiplas/genética , Adulto , Idoso , Biomarcadores Tumorais/genética , Feminino , Testes Genéticos/métodos , Mutação em Linhagem Germinativa/genética , Humanos , Masculino , Pessoa de Meia-Idade , FenótipoRESUMO
STUDY QUESTION: What are the sperm and egg donor rejection rates after expanded carrier screening (ECS)? SUMMARY ANSWER: Using an ECS panel looking at 46/47 genes, 17.6% of donors were rejected. WHAT IS KNOWN ALREADY: The use of ECS is becoming commonplace in assisted reproductive technology, including testing of egg and sperm donors. Most national guidelines recommend rejection of donors if they are carriers of a genetic disease. If the use of ECS increases, there will be a decline in the number of donors available. STUDY DESIGN, SIZE, DURATION: A review of the current preconception ECS panels available to donors was carried out through an online search. The genetic testing results of donors from Cryos International were analysed to determine how many were rejected on the basis of the ECS. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data on gamete donors and their carrier status was provided by Cryos International, who screen donors using their own bespoke ECS panel. The ECS panels identified through the review were compared to the Cryos International panel and data. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 16 companies and 42 associated ECS panels were reviewed. There were a total of 2673 unique disorders covered by the panels examined, with a mean of 329 disorders screened. None of these disorders were common to all panels. Cryos International screen 46 disorders in males and 47 in females. From 883 candidate donors, 17.6% (155/883) were rejected based on their ECS result. Carriers of alpha-thalassaemia represented the largest proportion of those rejected (19.4%, 30/155), then spinal muscular atrophy (15.5%, 24/155) and cystic fibrosis (14.8%, 23/155). LIMITATIONS, REASONS FOR CAUTION: Panel information was found on company websites and may not have been accurate. WIDER IMPLICATIONS OF THE FINDINGS: This study highlights the need for consistent EU regulations and guidelines that allow genetic matching of gamete donors to their recipients, preventing the need to reject donors who are known carriers. A larger ECS panel would be most beneficial; however, this would not be viable without matching of donors and recipients. STUDY FUNDING/COMPETING INTEREST(S): No specific funding was obtained. J.C.H. is the founder of Global Women Connected, a platform to discuss women's health issues and the Embryology and PGD Academy, who deliver education in clinical embryology. She has been paid to give a lecture by Cryos in 2019. A-B.S. is an employee of Cryos International. TRIAL REGISTRATION NUMBER: N/A.
Assuntos
Células Germinativas , Doadores de Tecidos , Feminino , Humanos , Masculino , Pesquisa , EspermatozoidesRESUMO
RESEARCH QUESTION: What is sperm donors' attitude towards offspring, anonymity and extended genetic screening? DESIGN: An online questionnaire for sperm donors was administered at Cryos International in the USA and Denmark between 9 and 30 September 2020. A total of 233 donors (37 in the USA and 196 in Denmark) completed the questionnaire. This study is unique because it was performed in a setting that allows donors to choose to be either ID-release or non-ID-release donors. RESULTS: Most donors had two motives to donate: helping childless people and/or financial compensation. ID-release donors differed significantly from non-ID-release donors in numerous aspects of the donation, including relationships with the offspring, information sharing with others and wanting information about offspring. In general, donors had a very positive attitude towards genetic testing and extended genetic screening. CONCLUSIONS: Offering the possibility for donors to be either ID-release or non-ID-release allows more donors to be recruited than if only one option were available. The multiple differences between the two donor types suggests that these are groups with profoundly different attitudes towards donation. The general attitude of donors towards genetic testing and expanded genetic screening is very positive but further studies on the attitude of candidate donors are needed.
Assuntos
Privacidade/psicologia , Espermatozoides , Doadores de Tecidos/psicologia , Adulto , Estudos Transversais , Testes Genéticos , Humanos , Disseminação de Informação , Masculino , Motivação , Doadores de Tecidos/estatística & dados numéricos , Adulto JovemRESUMO
Background: Preoperative genetic testing affects the surgical decision-making among women with breast cancer. To avoid breast-conserving surgery and to offer the possibility of mastectomy with immediate reconstruction in high-risk patients, genetic testing for pathogenic variants in BRCA1 or BRCA2 and a pedigree-based familial breast cancer risk assessment was offered to younger women with breast cancer in Denmark. We evaluated the impact of the risk stratification through genetic counseling on the uptake of contralateral prophylactic mastectomy (CPM).Material and methods: The prospective cohort study included all women with unilateral breast cancer before the age of 45 who participated in a genetic counseling program during their primary diagnostics in the Central Denmark Region (2013-2018). Each patient was followed from the time of the genetic test result to the end of follow-up to estimate the long-term uptake of CPM as a competing risk-adjusted cumulative incidence. We compared the uptake of CPM between the various genetic risk categories, ages of onset, and family histories in a multivariable Cox proportional hazards regression model, reporting hazard ratios (HR) with two-sided 95% confidence intervals (CIs).Results: 156 females, aged 21-44, learned their genetic test result within a median of 92 days [interquartile range (IQR): 75-114]. The maximal follow-up was 3.8 years (median 1.8; IQR: 0.49-2.5), after which 33% (95% CI: 24-42%) of the patients had undergone CPM. The uptake of CPM was inversely associated with the age of onset (HR 0.92; 95% CI: 0.86-0.98) and significantly higher among BRCA carriers (HR 2.9; 95% CI: 1.3-6.8) and patients from the high risk of breast cancer families (HR 5.6; 95% CI: 1.9-16) compared to the lower genetic risk categories.Conclusion: The risk stratification obtained through genetic counseling had a considerable impact on the surgical decision-making among younger women with breast cancer at long-term follow-up.
Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/prevenção & controle , Neoplasias da Mama/psicologia , Neoplasias da Mama/cirurgia , Aconselhamento Genético/métodos , Mutação , Mastectomia Profilática/psicologia , Adulto , Neoplasias da Mama/genética , Tomada de Decisões , Feminino , Aconselhamento Genético/psicologia , Humanos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Estudos Prospectivos , Adulto JovemRESUMO
BACKGROUND: The 15q11.2 deletion is frequently identified in the neurodevelopmental clinic. Case-control studies have associated the 15q11.2 deletion with neurodevelopmental disorders, and clinical case series have attempted to delineate a microdeletion syndrome with considerable phenotypic variability. The literature on this deletion is extensive and confusing, which is a challenge for genetic counselling. The aim of this study was to estimate the effect size of the 15q11.2 deletion and quantify its contribution to neurodevelopmental disorders. METHODS: We performed meta-analyses on new and previously published case-control studies and used statistical models trained in unselected populations with cognitive assessments. We used new (n=241) and previously published (n=150) data from a clinically referred group of deletion carriers. 15q11.2 duplications (new n=179 and previously published n=35) were used as a neutral control variant. RESULTS: The deletion decreases IQ by 4.3 points. The estimated ORs and respective frequencies in deletion carriers for intellectual disabilities, schizophrenia and epilepsy are 1.7 (3.4%), 1.5 (2%) and 3.1 (2.1%), respectively. There is no increased risk for heart malformations and autism. In the clinically referred group, the frequency and nature of symptoms in deletions are not different from those observed in carriers of the 15q11.2 duplication suggesting that most of the reported symptoms are due to ascertainment bias. CONCLUSIONS: We recommend that the deletion should be classified as 'pathogenic of mild effect size'. Since it explains only a small proportion of the phenotypic variance in carriers, it is not worth discussing in the developmental clinic or in a prenatal setting.
Assuntos
Transtorno Autístico/genética , Variações do Número de Cópias de DNA , Epilepsia/genética , Cardiopatias/genética , Deficiência Intelectual/genética , Transtornos do Neurodesenvolvimento/genética , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Cardiopatias/congênito , Humanos , Mutação com Perda de Função , Masculino , Deleção de SequênciaRESUMO
The 17p13.1 microdeletion syndrome is a recently described genomic disorder with a core clinical phenotype of intellectual disability, poor to absent speech, dysmorphic features, and a constellation of more variable clinical features, most prominently microcephaly. We identified five subjects with copy-number variants (CNVs) on 17p13.1 for whom we performed detailed clinical and molecular studies. Breakpoint mapping and retrospective analysis of published cases refined the smallest region of overlap (SRO) for microcephaly to a genomic interval containing nine genes. Dissection of this phenotype in zebrafish embryos revealed a complex genetic architecture: dosage perturbation of four genes (ASGR1, ACADVL, DVL2, and GABARAP) impeded neurodevelopment and decreased dosage of the same loci caused a reduced mitotic index in vitro. Moreover, epistatic analyses in vivo showed that dosage perturbations of discrete gene pairings induce microcephaly. Taken together, these studies support a model in which concomitant dosage perturbation of multiple genes within the CNV drive the microcephaly and possibly other neurodevelopmental phenotypes associated with rearrangements in the 17p13.1 SRO.
Assuntos
Anormalidades Múltiplas/genética , Dosagem de Genes/genética , Deficiência Intelectual/genética , Microcefalia/genética , Acil-CoA Desidrogenase de Cadeia Longa/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas Reguladoras de Apoptose , Receptor de Asialoglicoproteína/genética , Sequência de Bases , Linhagem Celular , Pontos de Quebra do Cromossomo , Deleção Cromossômica , Cromossomos Humanos Par 17/genética , Proteínas Desgrenhadas , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Proteínas Associadas aos Microtúbulos/genética , Dados de Sequência Molecular , Fosfoproteínas/genética , Estudos Retrospectivos , Análise de Sequência de DNA , Síndrome de Smith-Magenis , Síndrome , Peixe-ZebraRESUMO
Pathogenic germline mutations in the folliculin (FLCN) tumor suppressor gene predispose to Birt-Hogg-Dubé (BHD) syndrome, a rare disease characterized by the development of cutaneous hamartomas (fibrofolliculomas), multiple lung cysts, spontaneous pneumothoraces and renal cell cancer. In this study, we report the identification of 13 variants and three polymorphisms in the FLCN gene in 143 Danish patients or families with suspected BHD syndrome. Functional mini-gene splicing analysis revealed that two intronic variants (c.1062+2T>G and c.1177-5_1177-3del) introduced splicing aberrations. Eleven families exhibited the c.1062+2T>G mutation. Combined single nucleotide polymorphism array-haplotype analysis showed that these families share a 3-Mb genomic fragment containing the FLCN gene, revealing that the c.1062+2T>G mutation is a Danish founder mutation. On the basis of in silico prediction and functional splicing assays, we classify the 16 identified variants in the FLCN gene as follows: nine as pathogenic, one as likely pathogenic, three as likely benign and three as polymorphisms. In conclusion, the study describes the FLCN mutation spectrum in Danish BHD patients, and contributes to a better understanding of BHD syndrome and management of BHD patients.
Assuntos
Síndrome de Birt-Hogg-Dubé/genética , Pneumopatias/genética , Proteínas Proto-Oncogênicas/genética , Splicing de RNA/genética , Proteínas Supressoras de Tumor/genética , Sequência de Aminoácidos , Códon sem Sentido/genética , Dinamarca , Mutação da Fase de Leitura/genética , Predisposição Genética para Doença , Testes Genéticos , Humanos , Polimorfismo Genético/genéticaRESUMO
PURPOSE: Gain-of-function (GOF) mutations in the signal transducer and activator of transcription 1 (STAT1) result in unbalanced STAT signaling and cause immune dysregulation and immunodeficiency. The latter is often characterized by the susceptibility to recurrent Candida infections, resulting in the clinical picture of chronic mucocutaneous candidiasis (CMC). This study aims to assess the frequency of GOF STAT1 mutations in a large international cohort of CMC patients. METHODS: STAT1 was sequenced in genomic DNA from 57 CMC patients and 35 healthy family members. The functional relevance of nine different STAT1 variants was shown by flow cytometric analysis of STAT1 phosphorylation in patients' peripheral blood cells (PBMC) after stimulation with interferon (IFN)-α, IFN-γ or interleukin-27 respectively. Extended clinical data sets were collected and summarized for 26 patients. RESULTS: Heterozygous mutations within STAT1 were identified in 35 of 57 CMC patients (61%). Out of 39 familial cases from 11 families, 26 patients (67%) from 9 families and out of 18 sporadic cases, 9 patients (50%) were shown to have heterozygous mutations within STAT1. Thirteen distinct STAT1 mutations are reported in this paper. Eight of these mutations are known to cause CMC (p.M202V, p.A267V, p.R274W, p.R274Q, p.T385M, p.K388E, p.N397D, and p.F404Y). However, five STAT1 variants (p.F172L, p.Y287D, p.P293S, p.T385K and p.S466R) have not been reported before in CMC patients. CONCLUSION: STAT1 mutations are frequently observed in patients suffering from CMC. Thus, sequence analysis of STAT1 in CMC patients is advised. Measurement of IFN- or IL-induced STAT1 phosphorylation in PBMC provides a fast and reliable diagnostic tool and should be carried out in addition to genetic testing.
Assuntos
Candidíase Mucocutânea Crônica/diagnóstico , Síndromes de Imunodeficiência/diagnóstico , Leucócitos Mononucleares/imunologia , Mutação/genética , Fator de Transcrição STAT1/metabolismo , Adulto , Candidíase Mucocutânea Crônica/genética , Células Cultivadas , Citocinas/metabolismo , Análise Mutacional de DNA , Feminino , Humanos , Síndromes de Imunodeficiência/genética , Masculino , Linhagem , Fenótipo , Estrutura Terciária de Proteína/genética , Fator de Transcrição STAT1/genéticaRESUMO
BACKGROUND: The risk of cancer in men from BRCA1 and BRCA2 families is relevant to define to motivate genetic testing and optimize recommendations for surveillance. MATERIAL AND METHODS: We assessed the risk of cancer in male mutation carriers and their first-degree relatives in 290 BRCA1 and BRCA2 families with comparison to matched controls with the aim to motivate genetic testing and optimize recommendations for surveillance. RESULTS: Mutation carriers in BRCA1 families were not at increased risk of cancer, whereas mutation carriers in BRCA2 families were at increased risk of male breast cancer and prostate cancer with cumulative risks of 12.5% and 18.8%, respectively. Breast cancer developed at a mean age of 59 years, typically as ER/PR positive ductal carcinomas. Prostate cancer developed at a mean age of 68 years, with Gleason scores ≥ 8 in 40% of the tumors. The hazard ratio for BRCA2-associated prostate cancer was 3.7 (p < 0.001) in mutation carriers and 3.1 (p = 0.001) in first-degree relatives. Of the 37 prostate cancers, 19 were linked to four BRCA2 mutations within a region defined by c.6373-c.6492. Individuals with mutations herein had a HR of 3.7 for prostate cancer compared to individuals with mutations outside of this region. CONCLUSIONS: Male mutation carriers and first-degree relatives in BRCA2 families are at an increased risk of breast cancer and prostate cancer with a potential prostate cancer cluster region within exon 11 of BRCA2.
Assuntos
Neoplasias da Mama Masculina/genética , Genes BRCA1 , Genes BRCA2 , Mutação , Neoplasias da Próstata/genética , Fatores Etários , Idoso , Neoplasias da Mama Masculina/epidemiologia , Dinamarca/epidemiologia , Família , Predisposição Genética para Doença , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Neoplasias da Próstata/epidemiologia , RiscoRESUMO
BACKGROUND: Germline mutations in the succinate dehydrogenase complex genes SDHB, SDHC, and SDHD predispose to pheochromocytomas and paragangliomas. Here, we examine the SDHB, SDHC, and SDHD mutation spectrum in the Danish population by screening of 143 Danish pheochromocytoma and paraganglioma patients. METHODS: Mutational screening was performed by Sanger sequencing or next-generation sequencing. The frequencies of variants of unknown clinical significance, e.g. intronic, missense, and synonymous variants, were determined using the Exome Aggregation Consortium database, while the significance of missense mutations was predicted by in silico and loss of heterozygosity analysis when possible. RESULTS: We report 18 germline variants; nine in SDHB, six in SDHC, and three in SDHD. Of these 18 variants, eight are novel. We classify 12 variants as likely pathogenic/pathogenic, one as likely benign, and five as variants of unknown clinical significance. CONCLUSIONS: Identifying and classifying SDHB, SDHC, and SDHD variants present in the Danish population will augment the growing knowledge on variants in these genes and may support future clinical risk assessments.
RESUMO
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may affect the male reproductive system as it uses angiotensin-converting enzyme (ACE)2, which is expressed in testicular tissue, as an entry point into the cell. Few studies have evaluated the long-term effects of mild coronavirus disease 2019 (COVID-19) on testicular function, and insulin-like factor 3 (INSL3) levels have not previously been assessed during acute SARS-CoV-2 infection. OBJECTIVES: The aim of the study was to assess the impact of acute SARS-CoV-2 infection on testicular function including INSL3 and the presence of SARS-CoV-2 RNA in semen in non-hospitalised men with mild COVID-19. MATERIALS AND METHODS: This longitudinal study included 36 non-hospitalised SARS-CoV-2-positive men (median age 29 years). Inclusion was within seven days following a positive SARS-CoV-2 reverse-transcription polymerase chain reaction test. Reproductive hormone levels, semen parameters, and the presence of SARS-CoV-2 RNA in oropharyngeal and semen samples were assessed during acute SARS-CoV-2 infection (baseline) and at three- and six-month follow-up. Wilcoxon matched-pair signed-rank (two samples) test was used to assess time-related alterations in reproductive hormone levels and semen parameters. RESULTS: Lower plasma testosterone (T) (total and calculated free (c-fT)) and higher luteinising hormone (LH) concentrations were observed during acute SARS-CoV-2 infection (baseline) compared to three- and six-month follow-up. Consequently, ratios of c-fT/LH were lower at baseline compared to three- and six-month follow-up (p < 0.001 and p = 0.003, respectively). Concomitantly, lower INSL3 concentrations were observed at baseline compared to three-month follow-up (p = 0.01). The total number of motile spermatozoa was also lower at baseline compared to six-month follow-up (p = 0.02). The alterations were detected irrespective of whether the men had experienced SARS-CoV-2-related fever episodes or not. No SARS-CoV-2 RNA was detected in semen at any time point. DISCUSSION AND CONCLUSION: This study showed a reduction in testicular function, which was for the first time confirmed by INSL3, in men mildly affected by SARS-CoV-2 infection. The risk of transmission of SARS-CoV-2 RNA via semen seems to be low. Febrile episodes may impact testicular function, but a direct effect of SARS-CoV-2 cannot be excluded.
Assuntos
COVID-19 , Insulinas , Adulto , Humanos , Masculino , Estudos Longitudinais , Hormônio Luteinizante , RNA Viral , SARS-CoV-2 , Sêmen , TestosteronaRESUMO
Investigation of rare familial forms of renal cell carcinoma (RCC) has led to the identification of genes such as VHL and MET that are also implicated in the pathogenesis of sporadic RCC. In order to identify a novel candidate renal tumor suppressor gene, we characterized the breakpoints of a constitutional balanced translocation, t(5;19)(p15.3;q12), associated with familial RCC and found that a previously uncharacterized gene UBE2QL1 was disrupted by the chromosome 5 breakpoint. UBE2QL1 mRNA expression was downregulated in 78.6% of sporadic RCC and, although no intragenic mutations were detected, gene deletions and promoter region hypermethylation were detected in 17.3% and 20.3%, respectively, of sporadic RCC. Reexpression of UBE2QL1 in a deficient RCC cell line suppressed anchorage-independent growth. UBE2QL1 shows homology to the E2 class of ubiquitin conjugating enzymes and we found that (1) UBE2QL1 possesses an active-site cysteine (C88) that is monoubiquitinated in vivo, and (2) UBE2QL1 interacts with FBXW7 (an F box protein providing substrate recognition to the SCF E3 ubiquitin ligase) and facilitates the degradation of the known FBXW7 targets, CCNE1 and mTOR. These findings suggest UBE2QL1 as a novel candidate renal tumor suppressor gene.
Assuntos
Genes Supressores de Tumor , Predisposição Genética para Doença , Neoplasias Renais/genética , Translocação Genética , Enzimas de Conjugação de Ubiquitina/genética , Adulto , Sequência de Bases , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica/genética , Pontos de Quebra do Cromossomo , Cromossomos Humanos Par 19 , Cromossomos Humanos Par 5 , Metilação de DNA , Epigênese Genética , Proteínas F-Box/metabolismo , Proteína 7 com Repetições F-Box-WD , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/metabolismo , Dados de Sequência Molecular , Ligação Proteica , Transporte Proteico , Enzimas de Conjugação de Ubiquitina/química , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
People are becoming parents later in life and with increased parental age adverse reproductive outcomes are increased. Cryopreservation of gametes enables men and women to protect, prolong and seemingly preserve their fertility. Social freezing is an increasingly popular way of cryopreservation. During the COVID-19 pandemic, the gamete bank Cryos International experienced an increased influx of men wanting to deposit their sperm. A questionnaire-based study was initiated to investigate their motivations for doing so. The results showed that the men chose to deposit mainly due to medical indications (e.g. cancer and sex change), and that the COVID-19 pandemic had no significant influence on the reason for banking their sperm. Investigations into the altruistic reasons for depositing sperm (i.e. caring for reproductive masculinity) could shed new light onto the sparsely studied topic of male reproductive journeys.
Assuntos
COVID-19 , Preservação da Fertilidade , Humanos , Masculino , Feminino , Motivação , Pandemias , COVID-19/epidemiologia , Sêmen , Espermatozoides , CriopreservaçãoRESUMO
BACKGROUND: More knowledge about the long-term impact of sperm donation is essential as the donor's attitude towards donation may change over time. Personal and social developments may prompt a rethinking of previous actions and decisions, or even regret. Thus, the aim of this study was to explore the experiences and attitudes of men who were sperm donors more than 10 years ago. METHODS: From May to September 2021, semi-structured, qualitative interviews were conducted with 23 former donors (> 10 years since last donation) from Cryos International sperm bank. Two participants were non-anonymous donors and 21 were anonymous. The interviews were conducted by phone or via video (mean 24 minutes). All interviews were recorded, transcribed verbatim and rendered anonymous. Data were analyzed using thematic analysis. RESULTS: The analysis showed that most men had been donors for monetary and altruistic purposes, and now considered sperm donation as a closed chapter that was 'unproblematic and in the past'. Most men valued anonymity and emphasized the non-relatedness between donor and donor conceived offspring. Knowledge about recipients and donor offspring was seen as 'damaging' as it could create unwanted feelings of relatedness and responsibility towards them. All men acknowledged donor conceived persons' potential interests in knowing about their genetic heritage in order to understand appearance and personal traits, but also emphasized the donors' rights to anonymity. Potential breach of anonymity was generally considered 'highly problematic' as it was expected to disturb their families and force a relationship on them. CONCLUSION: This study reports on former donors who might not have volunteered for research due to lack of interest or protection of privacy. The majority of men valued anonymity and clearly demarcated a line between sperm donation and fatherhood, which was enforced by not knowing about the donor offspring or recipients.