RESUMO
Beckwith-Wiedemann syndrome (BWS) is a common genetic congenital disease characterized by somatic overgrowth and its broad clinical spectrum includes pre- and post-natal macrosomia, macroglossia, visceromegaly, increased risk of neonatal hypoglycemia, and development of embryonic tumors. BWS occurs due to genetic/epigenetic changes involving growth-regulating genes, located on region 11p15, with an important genotype-phenotype correlation. Congenital adrenal hyperplasia (CAH) comprises a spectrum of autosomal recessive diseases presenting a variety of clinical manifestations due to a deficiency in one of the enzymes involved in cortisol secretion. Early diagnosis based on newborn screening prevents the adrenal crisis and early infant death. However, high 17-hydroxyprogesterone (17-OHP) levels can occur in newborns or premature infants without CAH, in situations of stress due to maternal or neonatal factors. Here, we report new cases of false-positive diagnosis of 21-hydroxylase deficiency during newborn screening - two girls and one boy with BWS. Methylation-specific multiplex ligation-dependent probe amplification revealed a gain of methylation in the H19 differentially methylated region. Notably, all three cases showed a complete normalization of biochemical changes, highlighting the transient nature of these hormonal findings that imitate the classical form of CAH. This report sheds light on a new cause of false-positive 21-hydroxylase deficiency diagnosis during newborn screening: Beckwith-Wiedemann syndrome.
Assuntos
Hiperplasia Suprarrenal Congênita , Síndrome de Beckwith-Wiedemann , Masculino , Lactente , Feminino , Humanos , Recém-Nascido , Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Hiperplasia Suprarrenal Congênita/diagnóstico , Hiperplasia Suprarrenal Congênita/genética , Metilação de DNA , Triagem NeonatalRESUMO
INTRODUCTION: Epigenetic and genomic imprinting alterations of the 11p15.5 region cause excessive or deficient growth, which result in Beckwith-Wiedemann syndrome (BWS) or Silver-Russell syndrome (SRS), respectively. OBJECTIVE: To evaluate the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) methylation analysis technique in the diagnosis of BWS and SRS. METHODS: 11p15.5 methylation and variants were evaluated in patients with clinical diagnosis of BWS and SRS using the MS-MLPA technique in peripheral blood DNA. RESULTS: Paternal uniparental disomy and loss of maternal IC2 methylation were identified in two patients with BWS who had omphalocele and macroglossia, respectively. Paternal IC1hypomethylation was recorded in two patients with SRS of classic phenotype. CONCLUSIONS: Adequate genotype-phenotype correlation was observed with the methylation defects that were identified, which confirms the usefulness of MLPA as a first-line study in patients diagnosed with BWS and SRS.
INTRODUCCIÓN: Las alteraciones epigenéticas y genómicas de la región improntada 11p15.5 producen crecimiento excesivo o deficiente, que se manifiesta como síndrome de Beckwith-Wiedemann o síndrome de Silver-Russell, respectivamente. OBJETIVO: Evaluar la técnica de análisis de metilación MLPA (MS-MLPA, methylation-specific multiplex ligation-dependent probe amplification) en el diagnóstico de los síndromes de Beckwith-Wiedemann y de Silver-Russell. MÉTODOS: Se evaluó la metilación y las variantes de 11p15.5 en pacientes con diagnóstico clínico de síndrome de Beckwith-Wiedemann y síndrome de Silver-Russell mediante la técnica MS-MLPA en ADN de sangre periférica. RESULTADOS: Se identificó disomía uniparental paterna y pérdida de metilación del IC2 materno en dos pacientes con síndrome de Beckwith-Wiedemann, quienes presentaron onfalocele y macroglosia, respectivamente. Se registró hipometilación paterna del IC1 en dos pacientes con síndrome de Silver-Russell de fenotipo clásico. CONCLUSIONES: Se observó adecuada correlación genotipo-fenotipo con los defectos de metilación encontrados, lo que confirma la utilidad del MLPA como estudio de primera línea en pacientes con diagnóstico de síndrome de Beckwith-Wiedemann y síndrome de Silver-Russell.
Assuntos
Síndrome de Beckwith-Wiedemann , Síndrome de Silver-Russell , Humanos , Síndrome de Silver-Russell/diagnóstico , Síndrome de Silver-Russell/genética , Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Reação em Cadeia da Polimerase Multiplex/métodos , Metilação de DNA , Impressão GenômicaRESUMO
Multi-locus methylation defects (MLMDs) in imprinted loci have been reported in Beckwith-Wiedemann Syndrome (BWS). Large offspring syndrome (LOS), a phenotypic subgroup of abnormal offspring syndrome (AOS), is considered a molecular and phenotypic model for BWS. Both LOS and BWS have presented epigenetic defects in some common imprinted loci. In this study, methylation-specific restriction digestion assay - quantitative PCR was used to analyze the DNA methylation pattern in differentially methylated regions (DMRs) of the H19 (H19-DMR), KCNQ1OT1 (KvDMR1) and PEG1/MEST (PEG1-DMR) genes in bovine clone tissues from calves that did not survive after birth. Individual and tissue-specific changes in DNA methylation levels in the bovine KvDMR1, H19-DMR, and PEG1-DMR were observed. In contrast to what has been reported in the literature on BWS and AOS/LOS, the KvDMR1 showed gain (GOM) and loss (LOM) of DNA methylation. LOM and GOM events were found in the DMRs studied in animals produced by the same nucleus donor cell line. This is the first report of epimutations in the PEG1-DMR and GOM at the KvDMR1 found in bovine clones. The findings showed that epigenetic modification in imprinted loci in cloned cattle occurred in a multi-locus pattern similar to that seen in human imprinting disorders. Other multi-locus analyzes must be done to elucidate the MLMD pattern in AOS in bovine clones.
Assuntos
Síndrome de Beckwith-Wiedemann , Doenças dos Bovinos , Animais , Síndrome de Beckwith-Wiedemann/genética , Síndrome de Beckwith-Wiedemann/veterinária , Bovinos/genética , Doenças dos Bovinos/genética , Metilação de DNA , Epigênese Genética , Impressão Genômica , Técnicas de Transferência Nuclear/veterináriaRESUMO
In vitro fertilization and somatic cell nuclear transfer are assisted reproduction technologies commonly used in humans and cattle, respectively. Despite advances in these technologies, molecular failures can occur, increasing the chance of the onset of imprinting disorders in the offspring. Large offspring syndrome/abnormal offspring syndrome (LOS/AOS) has been described in cattle and has features such as hypergrowth, malformation of organs, and skeletal and placental defects. In humans, Beckwith-Wiedemann syndrome (BWS) has phenotypic characteristics similar to those found in LOS/AOS. In both syndromes, disruption of genomic imprinting associated with loss of parental-specific expression and parental-specific epigenetic marks is involved in the molecular etiology. Changes in the imprinting pattern of these genes lead to loss of imprinting (LOI) due to gain or loss of methylation, inducing the emergence of these syndromes. Several studies have reported locus-specific alterations in these syndromes, such as hypomethylation in imprinting control region 2 (KvDMR1) in BWS and LOS/AOS. These LOI events can occur at multiple imprinted loci in the same affected individual, which are called multi-locus methylation defect (MLMD) events. Although the bovine species has been proposed as a developmental model for human imprinting disorders, there is little information on bovine imprinted genes in the literature, even the correlation of epimutation data with clinical characteristics. In this study, we performed a systematic review of all the multi-locus LOI events described in human BWS and LOS/AOS, in order to determine in which imprinted genes the largest changes in the pattern of DNA methylation and expression occur, helping to fill gaps for a better understanding of the etiology of both syndromes.
Assuntos
Síndrome de Beckwith-Wiedemann , Doenças dos Bovinos , Animais , Síndrome de Beckwith-Wiedemann/genética , Síndrome de Beckwith-Wiedemann/veterinária , Bovinos , Doenças dos Bovinos/genética , Metilação de DNA , Feminino , Impressão Genômica , Placenta , Gravidez , Técnicas de Reprodução Assistida/veterináriaRESUMO
The Beckwith-Wiedemann syndrome is the most common genetic entity in overgrowth, with an approximate incidence of 1 in 10 00013 700births. Its broad clinical spectrum includes pre- and postnatal macrosomia, macroglossia, pinna abnormalities, abdominal wall defects, visceromegaly, and hyperinsulinemic hypoglycemia. This syndrome predisposes to childhood cancer and is caused by diverse genetic and/or epigenetic disorders that usually affect the regulation of genes imprinted on chromosome 11p15.5. The knowledge of (epi) genotype-phenotype correlations has prompted recommendations to propose different health care strategies, including tumor surveillance protocols based on molecular classification, aimed at standardizing clinical practice. The objective of this article is to describe the current status of the Beckwith-Wiedemann syndrome, a model of genomic imprinting.
El síndrome de Beckwith-Wiedemann es la entidad genética de sobrecrecimiento más común, con una incidencia aproximada de 1 en 10 000-13 700 nacimientos. Presenta un amplio espectro clínico, que incluye macrosomía pre- y posnatal, macroglosia, alteraciones en el pabellón auricular, defectos en la pared abdominal, visceromegalia e hipoglucemia por hiperinsulinemia. Es un síndrome de predisposición a cáncer en la infancia, causado por una variedad de alteraciones genéticas y/o epigenéticas que suelen afectar la regulación de los genes impresos en 11p15.5. Conocer las correlaciones (epi) genotipo/fenotipo ha impulsado recomendaciones para plantear las diferentes estrategias de atención, entre ellas, los protocolos de vigilancia de tumores basados en la clasificación molecular, con la finalidad de estandarizar la práctica clínica. El objetivo del presente artículo es mostrar el estado actual del síndrome de Beckwith-Wiedemann, un ejemplo de impronta genómica.
Assuntos
Síndrome de Beckwith-Wiedemann/genética , Impressão Genômica/genética , Neoplasias/genética , Síndrome de Beckwith-Wiedemann/complicações , Criança , Predisposição Genética para Doença , Genótipo , Humanos , Neoplasias/epidemiologia , FenótipoRESUMO
Os erros no padrão de imprinting são caracterizados como alterações epigenéticas por não afetarem a sequência nucleotídica do DNA mas modificarem a expressão gênica. Diversos aspectos do desenvolvimento embrionário, incluindo ocorrência de malformações congênitas e síndromes diversas, como a síndrome de Beckwith-Wiedemann (SBW; OMIM#130650) ocorrem em decorrência de eventos epigenéticos. A etiologia molecular de SBW é descrita com base em alterações epigenéticas na região cromossômica 11p15.5, que possui genes cuja expressão é regulada por dois centros de imprinting (IC) ou regiões diferencialmente metiladas (DMR). O IC1, que controla a expressão dos genes IGF2 e H19 apresenta metilação no alelo paterno e ausência de metilação no alelo materno; o IC2 encontra-se metilado normalmente no alelo materno, participando no controle da expressão dos genes CDKN1C, KCNQ1 e KNCQ1OT1. A etiologia de SBW também está associada a mutações pontuais em genes como CDKN1C, que codifica um inibidor de kinase dependente de ciclina da fase G1 do ciclo celular. O objetivo deste trabalho é investigar alterações genéticas e epigenéticas em amostras de DNA de 21 pacientes com SBW oriundos do Ambulatórido de Genética Médica do Instituto Nacional Fernandes Figueira IFF/FIOCRUZ. A abordagem metodológica consistiu na análise do perfil de metilação dos dois centros de imprinting de 11p15.5 com uso da ténica de MS-MLPA; análise de microssatélites dessa região, visando discriminar alterações epigenéticas em ambos os centros de imprinting de possíveis dissomias uniparentais (UPD); e a amplificação do gene CDKN1C, para sequenciamento de Sanger. Dos 21 pacientes analisados inicialmente por MS-MLPA, sete não apresentaram nenhuma alteração epigenética. Após reavaliação clínica foi confirmado o diagnóstico de SBW em três desses sete pacientes enquanto que os outros quatro pacientes apresentaram características clínicas isoladas associadas à SBW, sendo excluídos da amostra. Nos 14 pacientes restantes a análise de MS-MLPA identificou 10 casos de perda isolada de metilação no IC2, três casos de deleção em IC2 e um caso de ganho de metilação em IC1 com perda em IC2 (UPDp). Este trabalho confirmou estudos anteriores sobre a ocorrência de alterações epignéticas nesta síndrome; em consequência, permitindo uma orientação clínica e antecipação do monitoramento de pacientes quanto ao risco de tumores pediátricos.
Errors in imprinting pattern are characterized as epigenetic alterations, not affecting the nucleotide sequencing on DNA but affecting the gene expression. Several aspects of embrionary development, including occurrence of abnormalities and congenital disorders, as Beckwith-Wiedemann syndrome (BWS; OMIM#130650) occur due epignetics events. The molecular etiology of SBW is described based on epigenetic alterations in 11p15.5 chromossomic region, wich includes genes that have the expression regulated by two imprinting centers (IC) or differentialy methylated region (DMR). The IC1 regulates the gene expression of IGF2 and H19 genes. This IC shows a high methylation level only in the paternal allele. The IC2, normally methylated on the maternal allele, controls de gene expression of CDKN1C, KCNQ1 e KNCQ1OT1 genes. Besides this alterations, SBW's etiology is also associated with pontual mutations in CDKN1C gene, which encondes a cyclin dependent kinase inhibitor, acting on G1 celular cycle phase. The purpose of this study is to investigate genetics and epigenetics alterations in DNA samples of 21 patients with BWS from Instituto Nacional Fernandes Figueira IFF/FIOCRUZ. The methodological approach was based on the methylation profile's analysis of the two 11p15.5 imprinting centers using the MS-MLPA technique; microsatellite analysis of this region, aiming to distinguish epigenetic alterations on both imprinting centers from possible uniparental disomy (UPD); and CDKN1C gene Sanger sequencing. Seven of 21 patients analysed by MS-MLPA did not shown any epigenetic alteration. After a clinical revaluation the SBW diagnosys was confirmed to three of this sevens patients while the reamining four only shown isolated clinial features associated with BWS. On 14 patients MS-MLPA analysis identified 10 cases of isolated loss of methylation on IC2, three cases of IC2 deletions and one case with both gain of methylation on IC1 and loss of methylation on IC2 (UDPp). This study confirmed previous researches about the epigenetic alteration occurence ih BWS; in consequence, allowing a clinical monitoring to this patients due the risk of pediatric tumors.
Assuntos
Humanos , Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Expressão Gênica , Epigênese Genética , Inibidor de Quinase Dependente de Ciclina p57 , Epigenômica , BrasilRESUMO
Beckwith-Wiedemann Syndrome (BWS) is an overgrowth disorder with various congenital anomalies. Although the most classic constellation includes macrosomia, macroglossia, and omphalocele, nephrourological findings are commonly associated with BWS. Clinical presentation is highly variable because of its complex molecular heterogeneity, which involves changes in DNA methylation and disruption of growth regulatory genes. We report 3 pediatric patients, ages 13 months to 3 years old, who presented with clinical features consistent with BWS. A variety of nephrourological abnormalities were also noted, including posterior urethral valves, hydroureteronephrosis, and undescended testes. Genetic testing for all 3 patients revealed duplication of the region chromosome 11p15.5.
Assuntos
Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Duplicação Cromossômica , Cromossomos Humanos Par 11 , Síndrome de Beckwith-Wiedemann/diagnóstico por imagem , Pré-Escolar , Humanos , Lactente , MasculinoRESUMO
OBJECTIVE: To compare tumor risk in the 4 Beckwith-Wiedemann syndrome (BWS) molecular subgroups: Imprinting Control Region 1 Gain of Methylation (ICR1-GoM), Imprinting Control Region 2 Loss of Methylation (ICR2-LoM), Chromosome 11p15 Paternal Uniparental Disomy (UPD), and Cyclin-Dependent Kinase Inhibitor 1C gene (CDKN1C) mutation. STUDY DESIGN: Studies on BWS and tumor development published between 2000 and 2015 providing (epi)genotype-cancer correlations with histotype data were reviewed and meta-analysed with cancer histotypes as measured outcome and (epi)genotype as exposure. RESULTS: A total of 1370 patients with BWS were included: 102 developed neoplasms (7.4%). Tumor prevalence was 2.5% in ICR2-LoM, 13.8% in UPD, 22.8% in ICR1-GoM, and 8.6% in patients with CDKN1C mutations. Cancer ORs were 12.8 in ICR1-GoM, 6.5 in UPD, and 2.9 in patients with CDKN1C mutations compared with patients with ICR2-LoM. Wilms tumor was associated with ICR1-GoM (OR 68.3) and UPD (OR 13.2). UPD also was associated with hepatoblastoma (OR 5.2) and adrenal carcinoma (OR 7.0), and CDKN1C mutations with neuroblastic tumors (OR 7.2). CONCLUSION: Cancer screening in BWS could be differentiated on the basis of (epi)genotype and target specific histotypes. Patients with ICR1-GoM and UPD should undergo renal ultrasonography scanning, given their risk of Wilms tumor. Alpha feto protein monitoring for heptaoblastoma is suggested in patients with UPD. Adrenal carcinoma may deserve screening in patients with UPD. Patients with CDKN1C mutations may deserve neuroblastoma screening based on urinary markers and ultrasonography scanning. Finally, screening appears questionable in cases of ICR2-LoM, given low tumor risk.
Assuntos
Síndrome de Beckwith-Wiedemann/complicações , Síndrome de Beckwith-Wiedemann/genética , Neoplasias/genética , Síndrome de Beckwith-Wiedemann/diagnóstico , Criança , Protocolos Clínicos , Genótipo , Humanos , Neoplasias/classificação , Neoplasias/epidemiologia , Neoplasias/patologia , Fatores de Risco , Revisões Sistemáticas como AssuntoRESUMO
Adrenocortical tumours (ACT), which include adenomas, carcinomas and adrenal hyperplasia, may be associated with genetic syndromes, such as Li-Fraumeni syndrome, Beckwith-Wiedemann syndrome, multiple endocrine neoplasia type 1, familial adenomatous polyposis and Carney complex. Genetic defects have been found to be responsible for the disease in most of these syndromes, allowing genetic counselling to affected patients and family members. Here, we summarize the clinical criteria of these hereditary syndromes and briefly describe the genetic alterations related to them. In addition, we discuss the involvement of various genetic defects in the development of sporadic adrenocortical tumours.
Assuntos
Neoplasias do Córtex Suprarrenal/genética , Hiperplasia Suprarrenal Congênita/genética , Adenoma Adrenocortical/genética , Síndrome de Beckwith-Wiedemann/genética , Complexo de Carney/genética , Humanos , Síndrome de Li-Fraumeni/genética , Modelos Biológicos , Neoplasia Endócrina Múltipla Tipo 1/genética , Síndromes Neoplásicas Hereditárias/genéticaRESUMO
The insulin-like growth factor (IGF) signaling pathway has many important roles in normal cell growth and development. Remarkably, all of the components of this system (IGFs, receptors, and binding proteins) are expressed in human fetal adrenals. Beckwith-Wiedemann syndrome, a congenital overgrowth disorder characterized by a high risk of development of childhood tumors, is also distinguished by a high incidence of adrenocortical carcinomas. This disease has been associated with structural abnormalities at the 11p15 locus, which harbors the IGF2 gene as well as the genes coding for insulin, H19, and p57kip2. Notably, rearrangements at the 11p15 locus and overexpression of IGF2 were also described in sporadic adrenocortical tumors. In addition, the IGF2 overexpression was exclusively demonstrated in adults with adrenocortical tumors as a frequent feature of the malignant state. More recent studies demonstrated that the interaction of IGF-2 with IGF receptor type 1 (IGF-1R) plays also a pivotal role in adrenocortical tumorigenesis. IGF1R expression levels were significantly higher in pediatric adrenocortical carcinomas, suggesting that IGF1R expression represents a potential prognostic marker in this group of patients. These findings indicate that the IGF system is an important pathway for autonomous growth of adrenocortical cells and potential inhibitors of this system could be a rational therapeutic target for adrenocortical tumors.