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BACKGROUND: Imprinting disorders are rare diseases resulting from altered expression of imprinted genes, which exhibit parent-of-origin-specific expression patterns regulated through differential DNA methylation. A subgroup of patients with imprinting disorders have DNA methylation changes at multiple imprinted loci, a condition referred to as multi-locus imprinting disturbance (MLID). MLID is recognised in most but not all imprinting disorders and is also found in individuals with atypical clinical features; the presence of MLID often alters the management or prognosis of the affected person. Some cases of MLID are caused by trans-acting genetic variants, frequently not in the patients but their mothers, which have counselling implications. There is currently no consensus on the definition of MLID, clinical indications prompting testing, molecular procedures and methods for epigenetic and genetic diagnosis, recommendations for laboratory reporting, considerations for counselling, and implications for prognosis and management. The purpose of this study is thus to cover this unmet need. METHODS: A comprehensive literature search was conducted resulting in identification of more than 100 articles which formed the basis of discussions by two working groups focusing on clinical diagnosis (n = 12 members) and molecular testing (n = 19 members). Following eight months of preparations and regular online discussions, the experts from 11 countries compiled the preliminary documentation and determined the questions to be addressed during a face-to-face meeting which was held with the attendance of the experts together with four representatives of patient advocacy organisations. RESULTS: In light of available evidence and expert consensus, we formulated 16 propositions and 8 recommendations as interim guidance for the clinical and molecular diagnosis of MLID. CONCLUSIONS: MLID is a molecular designation, and for patients with MLID and atypical phenotypes, we propose the alternative term multi-locus imprinting syndrome. Due to the intrinsic variability of MLID, the guidelines underscore the importance of involving experts from various fields to ensure a confident approach to diagnosis, counselling, and care. The authors advocate for global, collaborative efforts in both basic and translational research to tackle numerous crucial questions that currently lack answers, and suggest reconvening within the next 3-5 years to evaluate the research advancements and update this guidance as needed.
Assuntos
Metilação de DNA , Impressão Genômica , Humanos , Impressão Genômica/genética , Metilação de DNA/genética , Testes Genéticos/métodosRESUMO
CONTEXT: Low birth weight, as seen in Silver-Russell syndrome (SRS), is associated with later cardiometabolic disease. Data on long term outcomes and adult body composition in SRS are limited. OBJECTIVE: To evaluate body composition and metabolic health in adults with SRS. DESIGN: This was an observational study. Body composition and metabolic health were assessed at a single appointment. Individuals with SRS were compared with unaffected men and women (from the Southampton Women's Survey (SWS)). SETTING: Clinical research facilities across the UK. PARTICIPANTS: 25 individuals with molecularly-confirmed SRS aged ≥18 years. MAIN OUTCOME MEASURES: Fat mass, lean mass, bone mineral density (BMD), blood pressure, lipids, and blood glucose were measured. RESULTS: 25 adults with SRS were included (52% female). The median age was 32.9 years (range 22.0-69.7). Fat percentage was greater in the SRS group than the SWS cohort (44.1% vs 30.3%, p<0.001). Fat mass index was similar (9.6 vs 7.8, p=0.3). Lean mass percentage (51.8% vs 66.2%, p<0.001) and lean mass index (13.5 kg/m2 vs 17.3 kg/m2, p<0.001) were lower in the SRS group than the SWS cohort. BMD was lower in the SRS group than the SWS cohort (1.08 vs 1.24, p<0.001) (all median values). Total cholesterol was ≥5mmol/L in 52.0%. Triglyceride levels were ≥1.7mmol/L in 20.8%. Fasting blood glucose levels were ≥6.1mmol/L in 25.0%. Hypertension was present in 33.3%. CONCLUSIONS: Adults with SRS have an unfavourable body composition and predisposition to cardiometabolic disease. These results support the need for a health surveillance strategy to mitigate adverse outcomes.
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PLAGL1 is one of a group of imprinted genes, whose altered expression causes imprinting disorders impacting growth, development, metabolism, and behavior. PLAGL1 over-expression causes transient neonatal diabetes mellitus (TNDM type 1) and, based on murine models, under-expression would be expected to cause growth restriction. However, only some reported individuals with upd(6)mat have growth restriction, giving rise to uncertainty about the role of PLAGL1 in human growth. Here we report three individuals investigated for growth restriction, two with upd(6)mat and one with a mosaic deletion of the paternally-inherited allele of PLAGL1. These cases add to evidence of its involvement in pre- and early post-natal human growth.
Assuntos
Impressão Genômica , Dissomia Uniparental , Recém-Nascido , Humanos , Animais , Camundongos , Impressão Genômica/genética , Fatores de Transcrição/genética , Proteínas de Ciclo Celular/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
BACKGROUND: Imprinting disorders, which affect growth, development, metabolism and neoplasia risk, are caused by genetic or epigenetic changes to genes that are expressed from only one parental allele. Disease may result from changes in coding sequences, copy number changes, uniparental disomy or imprinting defects. Some imprinting disorders are clinically heterogeneous, some are associated with more than one imprinted locus, and some patients have alterations affecting multiple loci. Most imprinting disorders are diagnosed by stepwise analysis of gene dosage and methylation of single loci, but some laboratories assay a panel of loci associated with different imprinting disorders. We looked into the experience of several laboratories using single-locus and/or multi-locus diagnostic testing to explore how different testing strategies affect diagnostic outcomes and whether multi-locus testing has the potential to increase the diagnostic efficiency or reveal unforeseen diagnoses. RESULTS: We collected data from 11 laboratories in seven countries, involving 16,364 individuals and eight imprinting disorders. Among the 4721 individuals tested for the growth restriction disorder Silver-Russell syndrome, 731 had changes on chromosomes 7 and 11 classically associated with the disorder, but 115 had unexpected diagnoses that involved atypical molecular changes, imprinted loci on chromosomes other than 7 or 11 or multi-locus imprinting disorder. In a similar way, the molecular changes detected in Beckwith-Wiedemann syndrome and other imprinting disorders depended on the testing strategies employed by the different laboratories. CONCLUSIONS: Based on our findings, we discuss how multi-locus testing might optimise diagnosis for patients with classical and less familiar clinical imprinting disorders. Additionally, our compiled data reflect the daily life experiences of diagnostic laboratories, with a lower diagnostic yield than in clinically well-characterised cohorts, and illustrate the need for systematising clinical and molecular data.
Assuntos
Síndrome de Beckwith-Wiedemann , Síndrome de Silver-Russell , Humanos , Impressão Genômica , Metilação de DNA , Síndrome de Silver-Russell/diagnóstico , Síndrome de Silver-Russell/genética , Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Transtornos do Crescimento/genética , Técnicas e Procedimentos DiagnósticosRESUMO
The overgrowth disorder Beckwith-Wiedemann syndrome and the growth restriction disorder Silver-Russell syndrome have been described as 'mirror' syndromes, in both their clinical features and molecular causes. Clinically, their nonspecific features, focused around continuous variables of atypical growth, make it hard to set diagnostic thresholds that are pragmatic without potentially excluding some cases. Molecularly, both are imprinting disorders, classically associated with 'opposite' genetic and epigenetic changes to genes on chromosome 11p15, but both are associated with somatic mosaicism as well as an increasing range of alternative (epi)genetic changes to other genes, which make molecular diagnosis an increasingly complex process. In this Current Opinion, we explore how the understanding of Beckwith-Wiedemann syndrome and Silver-Russell syndrome has evolved in recent years, stretching the canonical 'mirror' designations in different ways for the two disorders and how this is changing clinical and molecular diagnosis. We suggest some possible directions of travel toward more timely and stratified diagnosis, so that patients can access the early interventions that are so critical for good outcome.
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Síndrome de Beckwith-Wiedemann , Síndrome de Silver-Russell , Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Metilação de DNA , Epigênese Genética , Impressão Genômica , Humanos , Síndrome de Silver-Russell/diagnóstico , Síndrome de Silver-Russell/genéticaRESUMO
Beckwith-Wiedemann syndrome (BWS) and Temple syndrome (TS) are classical imprinting disorders (IDs) with nonconfluent clinical features. We report here on a patient with clinical features of both syndromes, in whom epimutations were found at the BWS and TS imprinted regions, consistent with multilocus imprinting disturbance (MLID). This is the first case report of a patient with clinical features of both conditions who was found to have loss of methylation (LOM) of KCNQ1OT1: TSS-DMR (ICR2) in the 11p15 imprinted region associated with BWS and LOM of MEG3: TSS-DMR in the 14q32 imprinted region associated with TS. The report draws attention to the importance of testing for MLID as a cause of atypical clinical presentations of patients with IDs.
Assuntos
Síndrome de Beckwith-Wiedemann , Síndrome de Silver-Russell , Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Metilação de DNA , Impressão Genômica/genética , Humanos , Síndrome de Silver-Russell/diagnóstico , Síndrome de Silver-Russell/genética , Dissomia Uniparental/genéticaRESUMO
OBJECTIVE: Silver-Russell syndrome (SRS) causes short stature. Growth hormone (GH) treatment aims to increase adult height. However, data are limited on the long-term outcomes of GH in patients with molecularly confirmed SRS. This study evaluated height, body mass index (BMI) and GH treatment in molecularly confirmed SRS. DESIGN: An observational study with retrospective data collection. PATIENTS: Individuals with molecularly confirmed SRS aged ≥13 years. MEASUREMENTS: Data were collected on height, height gain (change in height standard deviation score [SDS] from childhood to final or near-final height), BMI and gain in BMI (from childhood to adulthood) and previous GH treatment. RESULTS: Seventy-one individuals (40 female) were included. The median age was 22.0 years (range 13.2-69.7). The molecular diagnoses: H19/IGF2:IG-DMR LOM in 80.3% (57/71); upd(7)mat in 16.9% (12/71) and IGF2 mutation in 2.8% (2/71). GH treatment occurred in 77.5% (55/71). Total height gain was greater in GH-treated individuals (median 1.53 SDS vs. 0.53 SDS, p = .007), who were shorter at treatment initiation (-3.46 SDS vs. -2.91 SDS, p = .04) but reached comparable heights to GH-untreated individuals (-2.22 SDS vs. -2.74 SDS, p = .7). In GH-treated individuals, BMI SDS was lower at the most recent assessment (median -1.10 vs. 1.66, p = .002) with lower BMI gain (2.01 vs. 3.58, p = .006) despite similar early BMI SDS to GH-untreated individuals (median -2.65 vs. -2.78, p = .3). CONCLUSIONS: These results support the use of GH in SRS for increasing height SDS. GH treatment was associated with lower adult BMI which may reflect improved metabolic health even following discontinuation of therapy.
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Estatura , Índice de Massa Corporal , Hormônio do Crescimento Humano , Síndrome de Silver-Russell , Adolescente , Adulto , Idoso , Feminino , Hormônio do Crescimento Humano/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Síndrome de Silver-Russell/tratamento farmacológico , Adulto JovemRESUMO
BACKGROUND: Imprinting disorders are a group of congenital diseases which are characterized by molecular alterations affecting differentially methylated regions (DMRs). To date, at least twelve imprinting disorders have been defined with overlapping but variable clinical features including growth and metabolic disturbances, cognitive dysfunction, abdominal wall defects and asymmetry. In general, a single specific DMR is affected in an individual with a given imprinting disorder, but there are a growing number of reports on individuals with so-called multilocus imprinting disturbances (MLID), where aberrant imprinting marks (most commonly loss of methylation) occur at multiple DMRs. However, as the literature is fragmented, we reviewed the molecular and clinical data of 55 previously reported or newly identified MLID families with putative pathogenic variants in maternal effect genes (NLRP2, NLRP5, NLRP7, KHDC3L, OOEP, PADI6) and in other candidate genes (ZFP57, ARID4A, ZAR1, UHRF1, ZNF445). RESULTS: In 55 families, a total of 68 different candidate pathogenic variants were identified (7 in NLRP2, 16 in NLRP5, 7 in NLRP7, 17 in PADI6, 15 in ZFP57, and a single variant in each of the genes ARID4A, ZAR1, OOEP, UHRF1, KHDC3L and ZNF445). Clinical diagnoses of affected offspring included Beckwith-Wiedemann syndrome spectrum, Silver-Russell syndrome spectrum, transient neonatal diabetes mellitus, or they were suspected for an imprinting disorder (undiagnosed). Some families had recurrent pregnancy loss. CONCLUSIONS: Genomic maternal effect and foetal variants causing MLID allow insights into the mechanisms behind the imprinting cycle of life, and the spatial and temporal function of the different factors involved in oocyte maturation and early development. Further basic research together with identification of new MLID families will enable a better understanding of the link between the different reproductive issues such as recurrent miscarriages and preeclampsia in maternal effect variant carriers/families and aneuploidy and the MLID observed in the offsprings. The current knowledge can already be employed in reproductive and genetic counselling in specific situations.
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Síndrome de Beckwith-Wiedemann , Síndrome de Silver-Russell , Proteínas Adaptadoras de Transdução de Sinal/genética , Síndrome de Beckwith-Wiedemann/genética , Proteínas Estimuladoras de Ligação a CCAAT/genética , Metilação de DNA , Feminino , Impressão Genômica , Humanos , Herança Materna , Gravidez , Síndrome de Silver-Russell/diagnóstico , Síndrome de Silver-Russell/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
BACKGROUND: Silver-Russell syndrome (SRS) is an imprinting disorder characterised by prenatal and postnatal growth restriction, but its clinical features are non-specific and its differential diagnosis is broad. Known molecular causes of SRS include imprinting disturbance, single nucleotide variant (SNV), CNV or UPD affecting several genes; however, up to 40% of individuals with a clinical diagnosis of SRS currently receive no positive molecular diagnosis. METHODS: To determine whether whole-genome sequencing (WGS) could uncover pathogenic variants missed by current molecular testing, we analysed data of 72 participants recruited to the 100,000 Genomes Project within the clinical category of SRS. RESULTS: In 20 participants (27% of the cohort) we identified genetic variants plausibly accounting for SRS. Coding SNVs were identified in genes including CDKN1C, IGF2, IGF1R and ORC1. Maternal-effect variants were found in mothers of five participants, including two participants with imprinting disturbance and one with multilocus imprinting disorder. Two regions of homozygosity were suggestive of UPD involving imprinted regions implicated in SRS and Temple syndrome, and three plausibly pathogenic CNVs were found, including a paternal deletion of PLAGL1. In 48 participants with no plausible pathogenic variant, unbiased analysis of SNVs detected a potential association with STX4. CONCLUSION: WGS analysis can detect UPD, CNV and SNV and is potentially a valuable addition to diagnosis of SRS and related growth-restricting disorders.
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Anormalidades Múltiplas , Síndrome de Silver-Russell , Anormalidades Múltiplas/genética , Metilação de DNA , Feminino , Impressão Genômica/genética , Humanos , Herança Materna , Gravidez , Síndrome de Silver-Russell/diagnóstico , Síndrome de Silver-Russell/genética , Dissomia UniparentalRESUMO
OBJECTIVE: The psychosocial impact of growing up with Silver-Russell syndrome (SRS), characterised by growth failure and short stature in adulthood, has been explored in adults; however, there are no accounts of contemporary lived experience in adolescents. Such data could inform current healthcare guidance and transition to adult services. We aimed to explore the lived experience of adolescents with SRS. DESIGN/SETTING/PATIENTS: In-depth, semi-structured interviews were conducted between January 2015 and October 2016 with a sample of eight adolescents aged 13-18 (five girls) with genetically confirmed SRS from the UK. Qualitative interviews were transcribed and coded to identify similarities and differences using thematic analysis; codes were then grouped to form overarching themes. RESULTS: We identified four themes from the interview data: (1) the psychosocial challenges of feeling and looking different; (2) pain, disability and fatigue; (3) anticipated stigma; and (4) building resilience and acceptance. Despite adolescents accepting SRS in their lives, they described ongoing psychosocial challenges and anticipated greater problems to come, such as stigma from prospective employers. CONCLUSIONS: Adolescents with SRS may experience psychosocial difficulties from as young as 10 years old related to feeling and looking different; pain, disability and fatigue; anticipated stigma; and future challenges around employment. We discuss these findings in relation to recommendations for the care of adolescents with SRS to prepare them for adult life.
Assuntos
Adaptação Psicológica , Fadiga , Dor , Síndrome de Silver-Russell/psicologia , Estigma Social , Adolescente , Avaliação da Deficiência , Nanismo/psicologia , Emoções , Fadiga/diagnóstico , Fadiga/etiologia , Feminino , Humanos , Entrevistas como Assunto , Masculino , Dor/diagnóstico , Dor/etiologia , Pesquisa Qualitativa , Resiliência Psicológica , Síndrome de Silver-Russell/diagnósticoRESUMO
BACKGROUND: Silver-Russell syndrome is an imprinting disorder that restricts growth, resulting in short adult stature that may be ameliorated by treatment. Approximately 50% of patients have loss of methylation of the imprinting control region (H19/IGF2:IG-DMR) on 11p15.5 and 5%-10% have maternal uniparental disomy of chromosome 7. Most published research focuses on the childhood phenotype. Our aim was to describe the phenotypic characteristics of older patients with SRS. METHODS: A retrospective cohort of 33 individuals with a confirmed molecular diagnosis of SRS aged 13 years or above were carefully phenotyped. RESULTS: The median age of the cohort was 29.6 years; 60.6% had a height SD score (SDS) ≤-2 SDS despite 70% having received growth hormone treatment. Relative macrocephaly, feeding difficulties and a facial appearance typical of children with SRS were no longer discriminatory diagnostic features. In those aged ≥18 years, impaired glucose tolerance in 25%, hypertension in 33% and hypercholesterolaemia in 52% were noted. While 9/33 accessed special education support, university degrees were completed in 40.0% (>21 years). There was no significant correlation between quality of life and height SDS. 9/25 were parents and none of the 17 offsprings had SRS. CONCLUSION: Historical treatment regimens for SRS were not sufficient for normal adult growth and further research to optimise treatment is justified. Clinical childhood diagnostic scoring systems are not applicable to patients presenting in adulthood and SRS diagnosis requires molecular confirmation. Metabolic ill-health warrants further investigation but SRS is compatible with a normal quality of life including normal fertility in many cases.
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Fator de Crescimento Insulin-Like II/genética , RNA Longo não Codificante/genética , Síndrome de Silver-Russell/genética , Dissomia Uniparental/genética , Adolescente , Adulto , Idoso , Metilação de DNA/genética , Epigênese Genética , Feminino , Impressão Genômica/genética , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Qualidade de Vida , Síndrome de Silver-Russell/patologia , Dissomia Uniparental/patologia , Adulto JovemRESUMO
BACKGROUND: Human reproductive issues affecting fetal and maternal health are caused by numerous exogenous and endogenous factors, of which the latter undoubtedly include genetic changes. Pathogenic variants in either maternal or offspring DNA are associated with effects on the offspring including clinical disorders and nonviable outcomes. Conversely, both fetal and maternal factors can affect maternal health during pregnancy. Recently, it has become evident that mammalian reproduction is influenced by genomic imprinting, an epigenetic phenomenon that regulates the expression of genes according to their parent from whom they are inherited. About 1% of human genes are normally expressed from only the maternally or paternally inherited gene copy. Since numerous imprinted genes are involved in (embryonic) growth and development, disturbance of their balanced expression can adversely affect these processes. OBJECTIVE AND RATIONALE: This review summarises current our understanding of genomic imprinting in relation to human ontogenesis and pregnancy and its relevance for reproductive medicine. SEARCH METHODS: Literature databases (Pubmed, Medline) were thoroughly searched for the role of imprinting in human reproductive failure. In particular, the terms 'multilocus imprinting disturbances, SCMC, NLRP/NALP, imprinting and reproduction' were used in various combinations. OUTCOMES: A range of molecular changes to specific groups of imprinted genes are associated with imprinting disorders, i.e. syndromes with recognisable clinical features including distinctive prenatal features. Whereas the majority of affected individuals exhibit alterations at single imprinted loci, some have multi-locus imprinting disturbances (MLID) with less predictable clinical features. Imprinting disturbances are also seen in some nonviable pregnancy outcomes, such as (recurrent) hydatidiform moles, which can therefore be regarded as a severe form of imprinting disorders. There is growing evidence that MLID can be caused by variants in the maternal genome altering the imprinting status of the oocyte and the embryo, i.e. maternal effect mutations. Pregnancies of women carrying maternal affect mutations can have different courses, ranging from miscarriages to birth of children with clinical features of various imprinting disorders. WIDER IMPLICATIONS: Increasing understanding of imprinting disturbances and their clinical consequences have significant impacts on diagnostics, counselling and management in the context of human reproduction. Defining criteria for identifying pregnancies complicated by imprinting disorders facilitates early diagnosis and personalised management of both the mother and offspring. Identifying the molecular lesions underlying imprinting disturbances (e.g. maternal effect mutations) allows targeted counselling of the family and focused medical care in further pregnancies.
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Doenças Genéticas Inatas/diagnóstico , Doenças Genéticas Inatas/etiologia , Impressão Genômica/fisiologia , Resultado da Gravidez/genética , Reprodução/genética , Animais , Feminino , Doenças Genéticas Inatas/patologia , Humanos , Masculino , Mutação/fisiologia , Gravidez , PrognósticoRESUMO
BACKGROUND: A subset of individuals affected by imprinting disorders displays multi-locus imprinting disturbances (MLID). MLID has been associated with maternal-effect variants that alter the maintenance of methylation at germline-derived differentially methylated regions (gDMRs) in early embryogenesis. Pedigrees of individuals with MLID also include siblings with healthy phenotype. However, it is unknown if these healthy individuals have MLID themselves or if their methylation patterns differ from those associated with imprinting disorders, and in general, if MLID affects the clinical phenotype. METHODS: We have investigated gDMR methylation by locus-specific and whole-genome analyses in a family with multiple pregnancy losses, a child with Beckwith-Wiedemann syndrome (BWS) and a further child with no clinical diagnosis of imprinting disorder or other pathologies. RESULTS: We detected MLID with different methylation profiles in the BWS-affected and healthy siblings. Whole-exome sequencing demonstrated the presence of novel loss-of-function variants of NLRP5 in compound heterozygosity in the mother. The methylation profiles of the two siblings were compared with those of other cases with MLID and control groups by principal component analysis and unsupervised hierarchical clustering, but while their patterns were clearly separated from those of controls, we were unable to cluster those associated with specific clinical phenotypes among the MLID cases. CONCLUSION: The identification of two novel maternal-effect variants of NLRP5 associated with poly-abortivity and MLID adds further evidence to the role of this gene in the maintenance of genomic imprinting in early embryos. Furthermore, our results demonstrate that within these pedigrees, MLID can also be present in the progeny with healthy phenotype, indicating that some sort of compensation occurs between altered imprinted loci in these individuals. The analysis of larger cohorts of patients with MLID is needed to formulate more accurate epigenotype-phenotype correlations.
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Aborto Espontâneo/genética , Autoantígenos/genética , Síndrome de Beckwith-Wiedemann/genética , Mutação com Perda de Função , Herança Materna , Proteínas Mitocondriais/genética , Proteínas Nucleares/genética , Criança , Feminino , Estudo de Associação Genômica Ampla , Impressão Genômica , Humanos , Masculino , Linhagem , Fenótipo , Análise de Sequência de DNA , Sequenciamento do Exoma , Adulto JovemRESUMO
Germline mutations in fundamental epigenetic regulatory molecules including DNA methyltransferase 3 alpha (DNMT3A) are commonly associated with growth disorders, whereas somatic mutations are often associated with malignancy. We profiled genome-wide DNA methylation patterns in DNMT3A c.2312G > A; p.(Arg771Gln) carriers in a large Amish sibship with Tatton-Brown-Rahman syndrome (TBRS), their mosaic father, and 15 TBRS patients with distinct pathogenic de novo DNMT3A variants. This defined widespread DNA hypomethylation at specific genomic sites enriched at locations annotated as genes involved in morphogenesis, development, differentiation, and malignancy predisposition pathways. TBRS patients also displayed highly accelerated DNA methylation aging. These findings were most marked in a carrier of the AML-associated driver mutation p.Arg882Cys. Our studies additionally defined phenotype-related accelerated and decelerated epigenetic aging in two histone methyltransferase disorders: NSD1 Sotos syndrome overgrowth disorder and KMT2D Kabuki syndrome growth impairment. Together, our findings provide fundamental new insights into aberrant epigenetic mechanisms, the role of epigenetic machinery maintenance, and determinants of biological aging in these growth disorders.
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Envelhecimento/genética , DNA (Citosina-5-)-Metiltransferases/genética , Epigênese Genética , Transtornos do Crescimento/genética , Mutação , Anormalidades Múltiplas/genética , Adolescente , Adulto , Amish/genética , Criança , Metilação de DNA , DNA Metiltransferase 3A , Face/anormalidades , Doenças Hematológicas/genética , Humanos , Deficiência Intelectual/genética , Leucemia Mieloide Aguda/genética , Masculino , Metiltransferases , Morfogênese/genética , Síndrome , Doenças Vestibulares/genética , Adulto JovemRESUMO
The introduction of exome sequencing in the clinic has sparked tremendous optimism for the future of rare disease diagnosis, and there is exciting opportunity to further leverage these advances. To provide diagnostic clarity to all of these patients, however, there is a critical need for the field to develop and implement strategies to understand the mechanisms underlying all rare diseases and translate these to clinical care.
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Sequenciamento do Exoma/tendências , Doenças Raras/diagnóstico , Pesquisa Translacional Biomédica/métodos , Exoma , Testes Genéticos , Genoma Humano/genética , Sequenciamento de Nucleotídeos em Larga Escala/tendências , Humanos , Doenças Raras/genética , Análise de Sequência de DNA/métodos , Sequenciamento do Exoma/métodosRESUMO
Beckwith-Wiedemann syndrome (BWS) and Silver-Russell syndrome (SRS) are two imprinting disorders associated with opposite molecular alterations in the 11p15.5 imprinting centres. Their clinical diagnosis is confirmed by molecular testing in 50-70% of patients. The authors from different reference centres for BWS and SRS have identified single patients with unexpected and even contradictory molecular findings in respect to the clinical diagnosis. These patients clinically do not fit the characteristic phenotypes of SRS or BWS, but illustrate their clinical heterogeneity. Thus, comprehensive molecular testing is essential for accurate diagnosis and appropriate management, to avoid premature clinical diagnosis and anxiety for the families.
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Síndrome de Beckwith-Wiedemann/genética , Síndrome de Silver-Russell/genética , Síndrome de Beckwith-Wiedemann/diagnóstico , Cromossomos Humanos Par 11/genética , Metilação de DNA , Predisposição Genética para Doença/genética , Testes Genéticos , Humanos , Fenótipo , Síndrome de Silver-Russell/diagnósticoRESUMO
During reproductive age, approximately one in seven couples are confronted with fertility problems. While the aetiology is diverse, including infections, metabolic diseases, hormonal imbalances and iatrogenic effects, it is becoming increasingly clear that genetic factors have a significant contribution. Due to the complex nature of infertility that often hints at a multifactorial cause, the search for potentially causal gene mutations in idiopathic infertile couples has remained difficult. Idiopathic infertility patients with a suspicion of an underlying genetic cause can be expected to have mutations in genes that do not readily affect general health but are only essential in certain processes connected to fertility. In this review, we specifically focus on genes involved in meiosis and maternal-effect processes, which are of critical importance for reproduction and initial embryonic development. We give an overview of genes that have already been linked to infertility in human, as well as good candidates which have been described in other organisms. Finally, we propose a phenotypic range in which we expect an optimal diagnostic yield of a meiotic/maternal-effect gene panel.
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Predisposição Genética para Doença , Testes Genéticos , Infertilidade/diagnóstico , Infertilidade/genética , Animais , Regulação da Expressão Gênica , Aconselhamento Genético , Marcadores Genéticos , Testes Genéticos/métodos , Variação Genética , Humanos , Herança Materna , Meiose/genética , Fenótipo , Seleção GenéticaRESUMO
Genomic imprinting, the monoallelic and parent-of-origin-dependent expression of a subset of genes, is required for normal development, and its disruption leads to human disease. Imprinting defects can involve isolated or multilocus epigenetic changes that may have no evident genetic cause, or imprinting disruption can be traced back to alterations of cis-acting elements or trans-acting factors that control the establishment, maintenance and erasure of germline epigenetic imprints. Recent insights into the dynamics of the epigenome, including the effect of environmental factors, suggest that the developmental outcomes and heritability of imprinting disorders are influenced by interactions between the genome, the epigenome and the environment in germ cells and early embryos.
Assuntos
Metilação de DNA , Doenças Genéticas Inatas/genética , Genoma Humano , Impressão Genômica , Animais , HumanosRESUMO
OBJECTIVE: There is limited information on the psychosocial impact of growing up with Silver-Russell syndrome (SRS), characterised by slow growth in utero leading to short stature in adulthood. Such information could aid families in making difficult treatment decisions and guide management strategies for health professionals. We aimed to explore the lived experience of people with SRS across the lifespan. DESIGN/SETTING/PATIENTS: In-depth, semi-structured interviews were conducted between January 2015 and October 2016 with a sample of 15 adults (six women) with genetically confirmed SRS from the UK. Qualitative interviews were transcribed and coded to identify similarities and differences: codes were then grouped to form overarching themes. RESULTS: Four themes were identified from participant accounts: (1) appearance-related concerns extending beyond height; (2) strategies to deal with real and perceived threats; (3) women's experiences of pain, disability and feeling older than their years; and (4) feeling overlooked in romantic relationships. These themes show that other factors, beyond short stature, affect patient well-being and indicate a mismatch between patient need and healthcare provision. CONCLUSIONS: Challenges in SRS during childhood and adolescence were central to the psychosocial impact of SRS, and were not limited to height. These challenges, as well as symptoms such as pain and fatigue for women, have not previously been documented. To help individuals with SRS develop strategies to manage psychosocial issues, we recommend clinicians incorporate psychological services as an integral part of multidisciplinary teams managing individuals with SRS during childhood, adolescence and adulthood.
Assuntos
Adaptação Psicológica/fisiologia , Estatura , Nanismo , Dor , Síndrome de Silver-Russell , Adulto , Criança , Avaliação da Deficiência , Nanismo/etiologia , Nanismo/fisiopatologia , Nanismo/psicologia , Fadiga/diagnóstico , Fadiga/etiologia , Feminino , Humanos , Masculino , Avaliação das Necessidades , Dor/diagnóstico , Dor/etiologia , Psicologia , Fatores Sexuais , Síndrome de Silver-Russell/diagnóstico , Síndrome de Silver-Russell/epidemiologia , Síndrome de Silver-Russell/fisiopatologia , Síndrome de Silver-Russell/psicologia , Reino Unido/epidemiologiaRESUMO
The medieval English romance The King of Tars gives an account of a birth of a lump of flesh. This has been considered as fantastic and monstrous in past literature, the horrific union of a Christian and Saracen. However, while the text certainly speaks to miscegenation, we propose that this lump of flesh is actually a hydatidiform mole. We trace the hydatidiform mole from antiquity, surrounding it with contextual medieval examples, from theology, history and medicine, that also describe abnormal births as 'lumps of flesh'. By discussing medieval ideas of monsters as a warning sign, we interpret the lump of flesh in terms of abnormal births, seed transmission, parental contribution and sin. Ideas of warning, blame and intervention present themselves as a response to moles both in medieval texts as well as in modern reactions to hydatidiform moles. We explore the epigenetics of hydatidiform moles and relate them to the medieval text. In The King of Tars, the fault for the lump of flesh could reside with either parent; we find that this is also the case in the genetic formation of the hydatidiform mole; we also argue that the epigenetics supports medieval theories of seed transmission.