RESUMO
Spondylocarpotarsal synostosis syndrome (SCTS) is characterized by intervertebral fusions and fusion of the carpal and tarsal bones. Biallelic mutations in FLNB cause this condition in some families, whereas monoallelic variants in MYH3, encoding embryonic heavy chain myosin 3, have been implicated in dominantly inherited forms of the disorder. Here, five individuals without FLNB mutations from three families were hypothesized to be affected by recessive SCTS on account of sibling recurrence of the phenotype. Initial whole-exome sequencing (WES) showed that all five were heterozygous for one of two independent splice-site variants in MYH3. Despite evidence indicating that three of the five individuals shared two allelic haplotypes encompassing MYH3, no second variant could be located in the WES datasets. Subsequent genome sequencing of these three individuals demonstrated a variant altering a 5' UTR splice donor site (rs557849165 in MYH3) not represented by exome-capture platforms. When the cohort was expanded to 16 SCTS-affected individuals without FLNB mutations, nine had truncating mutations transmitted by unaffected parents, and six inherited the rs557849165 variant in trans, an observation at odds with the population allele frequency for this variant. The rs557849165 variant disrupts splicing in the 5' UTR but is still permissive of MYH3 translational initiation, albeit with reduced efficiency. Although some MYH3 variants cause dominant SCTS, these data indicate that others (notably truncating variants) do not, except in the context of compound heterozygosity for a second hypomorphic allele. These observations make genetic diagnosis challenging in the context of simplex presentations of the disorder.
Assuntos
Anormalidades Múltiplas/genética , Genes Recessivos , Vértebras Lombares/anormalidades , Doenças Musculoesqueléticas/genética , Mutação/genética , Cadeias Pesadas de Miosina/genética , Escoliose/congênito , Sinostose/genética , Vértebras Torácicas/anormalidades , Alelos , Mapeamento Cromossômico , Feminino , Filaminas/genética , Haplótipos/genética , Heterozigoto , Humanos , Masculino , Linhagem , Fenótipo , Splicing de RNA/genética , Escoliose/genética , Síndrome , Sequenciamento do ExomaRESUMO
Gout is a complex inflammatory arthritis affecting ~20% of people with an elevated serum urate level (hyperuricemia). Gout and hyperuricemia are essentially specific to humans and other higher primates, with varied prevalence across ancestral groups. SLC2A9 and ABCG2 are major loci associated with both urate and gout in multiple ancestral groups. However, fine mapping has been challenging due to extensive linkage disequilibrium underlying the associated regions. We used trans-ancestral fine mapping integrated with primate-specific genomic information to address this challenge. Trans-ancestral meta-analyses of GWAS cohorts of either European (EUR) or East Asian (EAS) ancestry resulted in single-variant resolution mappings for SLC2A9 (rs3775948 for urate and rs4697701 for gout) and ABCG2 (rs2622621 for gout). Tests of colocalization of variants in both urate and gout suggested existence of a shared candidate causal variant for SLC2A9 only in EUR and for ABCG2 only in EAS. The fine-mapped gout variant rs4697701 was within an ancient enhancer, whereas rs2622621 was within a primate-specific transposable element, both supported by functional evidence from the Roadmap Epigenomics project in human primary tissues relevant to urate and gout. Additional primate-specific elements were found near both loci and those adjacent to SLC2A9 overlapped with known statistical epistatic interactions associated with urate as well as multiple super-enhancers identified in urate-relevant tissues. We conclude that by leveraging ancestral differences trans-ancestral fine mapping has identified ancestral and functional variants for SLC2A9 or ABCG2 with primate-specific regulatory effects on urate and gout.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Proteínas Facilitadoras de Transporte de Glucose/genética , Gota/genética , Hiperuricemia/genética , Proteínas de Neoplasias/genética , Locos de Características Quantitativas , Característica Quantitativa Herdável , Sequências Reguladoras de Ácido Nucleico , Animais , Evolução Molecular , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Gota/patologia , Humanos , Hiperuricemia/patologia , Masculino , Polimorfismo de Nucleotídeo Único , Primatas , Especificidade da Espécie , Ácido Úrico/sangueRESUMO
Wilms tumour is a childhood tumour that arises as a consequence of somatic and rare germline mutations, the characterisation of which has refined our understanding of nephrogenesis and carcinogenesis. Here we report that germline loss of function mutations in TRIM28 predispose children to Wilms tumour. Loss of function of this transcriptional co-repressor, which has a role in nephrogenesis, has not previously been associated with cancer. Inactivation of TRIM28, either germline or somatic, occurred through inactivating mutations, loss of heterozygosity or epigenetic silencing. TRIM28-mutated tumours had a monomorphic epithelial histology that is uncommon for Wilms tumour. Critically, these tumours were negative for TRIM28 immunohistochemical staining whereas the epithelial component in normal tissue and other Wilms tumours stained positively. These data, together with a characteristic gene expression profile, suggest that inactivation of TRIM28 provides the molecular basis for defining a previously described subtype of Wilms tumour, that has early age of onset and excellent prognosis.
Assuntos
Mutação em Linhagem Germinativa , Neoplasias Renais/genética , Mutação com Perda de Função , Recidiva Local de Neoplasia/genética , Proteína 28 com Motivo Tripartido/genética , Tumor de Wilms/genética , Adulto , Biomarcadores Tumorais/genética , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Humanos , Rim/patologia , Neoplasias Renais/epidemiologia , Neoplasias Renais/patologia , Masculino , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/patologia , Prognóstico , Urotélio/patologia , Sequenciamento do Exoma , Tumor de Wilms/epidemiologia , Tumor de Wilms/patologia , Adulto JovemRESUMO
We report 15 individuals with de novo pathogenic variants in WDR26. Eleven of the individuals carry loss-of-function mutations, and four harbor missense substitutions. These 15 individuals comprise ten females and five males, and all have intellectual disability with delayed speech, a history of febrile and/or non-febrile seizures, and a wide-based, spastic, and/or stiff-legged gait. These subjects share a set of common facial features that include a prominent maxilla and upper lip that readily reveal the upper gingiva, widely spaced teeth, and a broad nasal tip. Together, these features comprise a recognizable facial phenotype. We compared these features with those of chromosome 1q41q42 microdeletion syndrome, which typically contains WDR26, and noted that clinical features are consistent between the two subsets, suggesting that haploinsufficiency of WDR26 contributes to the pathology of 1q41q42 microdeletion syndrome. Consistent with this, WDR26 loss-of-function single-nucleotide mutations identified in these subjects lead to nonsense-mediated decay with subsequent reduction of RNA expression and protein levels. We derived a structural model of WDR26 and note that missense variants identified in these individuals localize to highly conserved residues of this WD-40-repeat-containing protein. Given that WDR26 mutations have been identified in â¼1 in 2,000 of subjects in our clinical cohorts and that WDR26 might be poorly annotated in exome variant-interpretation pipelines, we would anticipate that this disorder could be more common than currently appreciated.
Assuntos
Fácies , Marcha/genética , Haploinsuficiência/genética , Deficiência Intelectual/genética , Proteínas/genética , Convulsões/genética , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Aminoácidos , Sequência de Bases , Pré-Escolar , Deleção Cromossômica , Feminino , Crescimento e Desenvolvimento/genética , Humanos , Deficiência Intelectual/complicações , Masculino , Mutação/genética , Proteínas/química , Estabilidade de RNA/genética , Convulsões/complicações , SíndromeRESUMO
Frontometaphyseal dysplasia (FMD) is a progressive sclerosing skeletal dysplasia affecting the long bones and skull. The cause of FMD in some individuals is gain-of-function mutations in FLNA, although how these mutations result in a hyperostotic phenotype remains unknown. Approximately one half of individuals with FMD have no identified mutation in FLNA and are phenotypically very similar to individuals with FLNA mutations, except for an increased tendency to form keloid scars. Using whole-exome sequencing and targeted Sanger sequencing in 19 FMD-affected individuals with no identifiable FLNA mutation, we identified mutations in two genes-MAP3K7, encoding transforming growth factor ß (TGF-ß)-activated kinase (TAK1), and TAB2, encoding TAK1-associated binding protein 2 (TAB2). Four mutations were found in MAP3K7, including one highly recurrent (n = 15) de novo mutation (c.1454C>T [ p.Pro485Leu]) proximal to the coiled-coil domain of TAK1 and three missense mutations affecting the kinase domain (c.208G>C [p.Glu70Gln], c.299T>A [p.Val100Glu], and c.502G>C [p.Gly168Arg]). Notably, the subjects with the latter three mutations had a milder FMD phenotype. An additional de novo mutation was found in TAB2 (c.1705G>A, p.Glu569Lys). The recurrent mutation does not destabilize TAK1, or impair its ability to homodimerize or bind TAB2, but it does increase TAK1 autophosphorylation and alter the activity of more than one signaling pathway regulated by the TAK1 kinase complex. These findings show that dysregulation of the TAK1 complex produces a close phenocopy of FMD caused by FLNA mutations. Furthermore, they suggest that the pathogenesis of some of the filaminopathies caused by FLNA mutations might be mediated by misregulation of signaling coordinated through the TAK1 signaling complex.
Assuntos
Testa/anormalidades , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Mutação/genética , Osteocondrodisplasias/genética , Transdução de Sinais/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Feminino , Filaminas/genética , Humanos , Sistema de Sinalização das MAP Quinases/genética , Masculino , NF-kappa B/metabolismo , Osteocondrodisplasias/metabolismo , Fosforilação , Ligação Proteica , Multimerização ProteicaRESUMO
Loss-of-function mutations in the X-linked gene FLNA can lead to abnormal neuronal migration, vascular and cardiac defects, and congenital intestinal pseudo-obstruction (CIPO), the latter characterized by anomalous intestinal smooth muscle layering. Survival in male hemizygotes for such mutations is dependent on retention of residual FLNA function but it is unclear why a subgroup of males with mutations in the 5' end of the gene can present with CIPO alone. Here, we demonstrate evidence for the presence of two FLNA isoforms differing by 28 residues at the N-terminus initiated at ATG+1 and ATG+82 . A male with CIPO (c.18_19del) exclusively expressed FLNA ATG+82 , implicating the longer protein isoform (ATG+1 ) in smooth muscle development. In contrast, mutations leading to reduction of both isoforms are associated with compound phenotypes affecting the brain, heart, and intestine. RNA-seq data revealed three distinct transcription start sites, two of which produce a protein isoform utilizing ATG+1 while the third utilizes ATG+82 . Transcripts sponsoring translational initiation at ATG+1 predominate in intestinal smooth muscle, and are more abundant compared with the level measured in fibroblasts. Together these observations describe a new mechanism of tissue-specific regulation of FLNA that could reflect the differing mechanical requirements of these cell types during development.
Assuntos
Filaminas/genética , Estudos de Associação Genética , Heterogeneidade Genética , Mutação com Perda de Função , Fenótipo , Transcrição Gênica , Adolescente , Encéfalo/anormalidades , Encéfalo/diagnóstico por imagem , Criança , Sequência Conservada , Análise Mutacional de DNA , Feminino , Filaminas/química , Filaminas/metabolismo , Trato Gastrointestinal/metabolismo , Expressão Gênica , Humanos , Imageamento por Ressonância Magnética , Masculino , Músculo Liso/metabolismo , Isoformas de Proteínas , Adulto JovemRESUMO
Robinow syndrome (RS) is a phenotypically and genetically heterogeneous condition that can be caused by mutations in genes encoding components of the non-canonical Wnt signaling pathway. In contrast, germline mutations that act to increase canonical Wnt signaling lead to distinctive osteosclerotic phenotypes. Here, we identified de novo frameshift mutations in DVL1, a mediator of both canonical and non-canonical Wnt signaling, as the cause of RS-OS, an RS subtype involving osteosclerosis, in three unrelated individuals. The mutations all delete the DVL1 C terminus and replace it, in each instance, with a novel, highly basic sequence. We showed the presence of mutant transcript in fibroblasts from one individual with RS-OS and demonstrated unimpaired protein stability with transfected GFP-tagged constructs bearing a frameshift mutation. In vitro TOPFlash assays, in apparent contradiction to the osteosclerotic phenotype, revealed that the mutant allele was less active than the wild-type allele in the canonical Wnt signaling pathway. However, when the mutant and wild-type alleles were co-expressed, canonical Wnt activity was 2-fold higher than that in the wild-type construct alone. This work establishes that DVL1 mutations cause a specific RS subtype, RS-OS, and that the osteosclerosis associated with this subtype might be the result of an interaction between the wild-type and mutant alleles and thus lead to elevated canonical Wnt signaling.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/patologia , Nanismo/genética , Nanismo/patologia , Mutação da Fase de Leitura/genética , Deformidades Congênitas dos Membros/genética , Deformidades Congênitas dos Membros/patologia , Osteosclerose/genética , Fosfoproteínas/genética , Anormalidades Urogenitais/genética , Anormalidades Urogenitais/patologia , Via de Sinalização Wnt/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Desgrenhadas , Proteínas de Fluorescência Verde/metabolismo , Humanos , Fosfoproteínas/metabolismo , FosforilaçãoRESUMO
The periosteum contributes to bone repair and maintenance of cortical bone mass. In contrast to the understanding of bone development within the epiphyseal growth plate, factors that regulate periosteal osteogenesis have not been studied as intensively. Osteofibrous dysplasia (OFD) is a congenital disorder of osteogenesis and is typically sporadic and characterized by radiolucent lesions affecting the cortical bone immediately under the periosteum of the tibia and fibula. We identified germline mutations in MET, encoding a receptor tyrosine kinase, that segregate with an autosomal-dominant form of OFD in three families and a mutation in a fourth affected subject from a simplex family and with bilateral disease. Mutations identified in all families with dominant inheritance and in the one simplex subject with bilateral disease abolished the splice inclusion of exon 14 in MET transcripts, which resulted in a MET receptor (MET(Δ14)) lacking a cytoplasmic juxtamembrane domain. Splice exclusion of this domain occurs during normal embryonic development, and forced induction of this exon-exclusion event retarded osteoblastic differentiation in vitro and inhibited bone-matrix mineralization. In an additional subject with unilateral OFD, we identified a somatic MET mutation, also affecting exon 14, that substituted a tyrosine residue critical for MET receptor turnover and, as in the case of the MET(Δ14) mutations, had a stabilizing effect on the mature protein. Taken together, these data show that aberrant MET regulation via the juxtamembrane domain subverts core MET receptor functions that regulate osteogenesis within cortical diaphyseal bone.
Assuntos
Doenças do Desenvolvimento Ósseo/genética , Éxons , Mutação em Linhagem Germinativa , Osteogênese/genética , Periósteo/metabolismo , Proteínas Proto-Oncogênicas c-met/genética , Adulto , Sequência de Bases , Doenças do Desenvolvimento Ósseo/metabolismo , Doenças do Desenvolvimento Ósseo/patologia , Diferenciação Celular , Criança , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genes Dominantes , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Osteoblastos/metabolismo , Osteoblastos/patologia , Linhagem , Periósteo/crescimento & desenvolvimento , Periósteo/patologia , Cultura Primária de Células , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-met/metabolismo , Splicing de RNARESUMO
Frontometaphyseal dysplasia (FMD) is caused by gain-of-function mutations in the X-linked gene FLNA in approximately 50% of patients. Recently we characterized an autosomal dominant form of FMD (AD-FMD) caused by mutations in MAP3K7, which accounts for the condition in the majority of patients who lack a FLNA mutation. We previously also described a patient with a de novo variant in TAB2, which we hypothesized was causative of another form of AD-FMD. In this study, a cohort of 20 individuals with AD-FMD is clinically evaluated. This cohort consists of 15 individuals with the recently described, recurrent mutation (c.1454C>T) in MAP3K7, as well as three individuals with missense mutations that result in substitutions in the N-terminal kinase domain of TGFß-activated kinase 1 (TAK1), encoded by MAP3K7. Additionally, two individuals have missense variants in the gene TAB2, which encodes a protein with a close functional relationship to TAK1, TAK1-associated binding protein 2 (TAB2). Although the X-linked and autosomal dominant forms of FMD are very similar, there are distinctions to be made between the two conditions. Individuals with AD-FMD have characteristic facial features, and are more likely to be deaf, have scoliosis and cervical fusions, and have a cleft palate. Furthermore, there are features only found in AD-FMD in our review of the literature including valgus deformity of the feet and predisposition to keloid scarring. Finally, intellectual disability is present in a small number of subjects with AD-FMD but has not been described in association with X-linked FMD.
RESUMO
PURPOSE: Corneal dystrophies are a genetically heterogeneous group of disorders. We previously described a family with an autosomal dominant epithelial recurrent erosion dystrophy (ERED). We aimed to identify the underlying genetic cause of ERED in this family and 3 additional ERED families. We sought to characterize the potential function of the candidate genes using the human and zebrafish cornea. DESIGN: Case series study of 4 white families with a similar ERED. An experimental study was performed on human and zebrafish tissue to examine the putative biological function of candidate genes. PARTICIPANTS: Four ERED families, including 28 affected and 17 unaffected individuals. METHODS: HumanLinkage-12 arrays (Illumina, San Diego, CA) were used to genotype 17 family members. Next-generation exome sequencing was performed on an uncle-niece pair. Segregation of potential causative mutations was confirmed using Sanger sequencing. Protein expression was determined using immunohistochemistry in human and zebrafish cornea. Gene expression in zebrafish was assessed using whole-mount in situ hybridization. Morpholino-induced transient gene knockdown was performed in zebrafish embryos. MAIN OUTCOME MEASURES: Linkage microarray, exome analysis, DNA sequence analysis, immunohistochemistry, in situ hybridization, and morpholino-induced genetic knockdown results. RESULTS: Linkage microarray analysis identified a candidate region on chromosome chr10:12,576,562-112,763,135, and exploration of exome sequencing data identified 8 putative pathogenic variants in this linkage region. Two variants segregated in 06NZ-TRB1 with ERED: COL17A1 c.3156CâT and DNAJC9 c.334GâA. The COL17A1 c.3156CâT variant segregated in all 4 ERED families. We showed biologically relevant expression of these proteins in human cornea. Both proteins are expressed in the cornea of zebrafish embryos and adults. Zebrafish lacking Col17a1a and Dnajc9 during development show no gross corneal phenotype. CONCLUSIONS: The COL17A1 c.3156CâT variant is the likely causative mutation in our recurrent corneal erosion families, and its presence in 4 independent families suggests that it is prevalent in ERED. This same COL17A1 c.3156CâT variant recently was identified in a separate pedigree with ERED. Our study expands the phenotypic spectrum of COL17A1 disease from autosomal recessive epidermolysis bullosa to autosomal dominant ERED and identifies COL17A1 as a key protein in maintaining integrity of the corneal epithelium.
Assuntos
Processamento Alternativo/genética , Autoantígenos/genética , Distrofias Hereditárias da Córnea/genética , Epitélio Corneano/patologia , Mutação , Colágenos não Fibrilares/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Animais , Criança , Distrofias Hereditárias da Córnea/diagnóstico , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/fisiologia , Inativação Gênica , Ligação Genética , Proteínas de Choque Térmico HSP40/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imuno-Histoquímica , Hibridização In Situ , Masculino , Repetições de Microssatélites , Microscopia Confocal , Pessoa de Meia-Idade , Linhagem , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Peixe-Zebra , Colágeno Tipo XVIIRESUMO
OBJECTIVES: Non-syndromic CMM has a complex phenotype. Abnormal corpus callosum and corticospinal tract processes are suggested mechanisms of the mirror movements. To further explore behavioural and neural phenotype(s) the present study tests the hypothesis that the response readiness network comprising supplementary motor area (SMA) and connections with motor cortex (M1) functions abnormally in CMM. METHODS: Twelve participants with (non-syndromic) CMM and a control group (n = 28) were tested on a probabilistic Go-NoGo task while electroencephalography (EEG) was recorded to assess possible group differences in lateralized readiness of voluntary hand movements together with measures of SMA-M1 functional connectivity. RESULTS: The CMM group demonstrated delayed lateralized readiness and stronger functional connectivity between left-brain SMA-M1 regions. Connectivity strength was correlated with measures of behavioural performance but not with extent of mirroring. CONCLUSIONS: Abnormalities in brain processes upstream of movement output likely reflect neurocompensation as a result of lifelong experience with mirroring in CMM. SIGNIFICANCE: These findings extend the known neural abnormalities in CMM to include brain networks upstream from those involved in motor output and raise the question of whether neurocompensatory plasticity might be involved.
RESUMO
Emery-Dreifuss muscular dystrophy (EDMD) is characterised by early-onset joint contractures, progressive muscular weakness and wasting and late-onset cardiac disease. The more common X-linked recessive form of EDMD is caused by mutations in either EMD (encoding emerin) or FHL1 (encoding four and a half LIM domains 1), while mutations in LMNA (encoding lamin A/C), SYNE1 (encoding nesprin-1) and SYNE2 (encoding nesprin-2) lead to autosomal dominant forms of the condition. Here, we identify a three-generation family with an extended EDMD phenotype due to a novel indel mutation in FHL1 that differentially affects the relative expression of the three known transcript isoforms produced from this locus. The additional phenotypic manifestations in this family-proportionate short stature, facial dysmorphism, pulmonary valvular stenosis, thoracic scoliosis, brachydactyly, pectus deformities and genital abnormalities-are reminiscent of phenotypes seen with dysregulated Ras-mitogen-activated protein kinase (RAS-MAPK) signalling [Noonan syndrome (NS) and related disorders]. The misexpression of FHL1 transcripts precipitated by this mutation, together with the role of FHL1 in the regulation of RAS-MAPK signalling, suggests that this mutation confers a complex phenotype through both gain- and loss-of-function mechanisms. This indel mutation in FHL1 broadens the spectrum of FHL1-related disorders and implicates it in the pathogenesis of NS spectrum disorders.
Assuntos
Mutação INDEL/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas com Domínio LIM/genética , Proteínas Musculares/genética , Distrofia Muscular de Emery-Dreifuss/genética , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Proteínas Quinases Ativadas por Mitógeno/genética , Distrofia Muscular de Emery-Dreifuss/metabolismo , Distrofia Muscular de Emery-Dreifuss/patologia , Linhagem , Fenótipo , Isoformas de Proteínas/genéticaRESUMO
Tuberous sclerosis complex (TSC) is an inheritable disorder characterized by the formation of benign yet disorganized tumors in multiple organ systems. Germline mutations in the TSC1 (hamartin) or more frequently TSC2 (tuberin) genes are causative for TSC. The malignant manifestations of TSC, pulmonary lymphangioleiomyomatosis (LAM) and renal angiomyolipoma (AML), may also occur as independent sporadic perivascular epithelial cell tumor (PEComa) characterized by somatic TSC2 mutations. Thus, discerning TSC from the copresentation of sporadic LAM and sporadic AML may be obscured in TSC patients lacking additional features. In this report, we present a case study on a single patient initially reported to have sporadic LAM and a mucinous duodenal adenocarcinoma deficient in DNA mismatch repair proteins. Moreover, the patient had a history of Wilms' tumor, which was reclassified as AML following the LAM diagnosis. Therefore, we investigated the origins and relatedness of these tumors. Using germline whole-genome sequencing, we identified a premature truncation in one of the patient's TSC2 alleles. Using immunohistochemistry, loss of tuberin expression was observed in AML and LAM tissue. However, no evidence of a somatic loss of heterozygosity or DNA methylation epimutations was observed at the TSC2 locus, suggesting alternate mechanisms may contribute to loss of the tumor suppressor protein. In the mucinous duodenal adenocarcinoma, no causative mutations were found in the DNA mismatch repair genes MLH1, MSH2, MSH6, or PMS2 Rather, clonal deconvolution analyses were used to identify mutations contributing to pathogenesis. This report highlights both the utility of using multiple sequencing techniques and the complexity of interpreting the data in a clinical context.
Assuntos
Adenocarcinoma , Angiomiolipoma , Neoplasias Renais , Leucemia Mieloide Aguda , Esclerose Tuberosa , Angiomiolipoma/genética , Angiomiolipoma/patologia , Feminino , Humanos , Masculino , Esclerose Tuberosa/diagnóstico , Esclerose Tuberosa/genética , Esclerose Tuberosa/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/genética , Proteínas Supressoras de Tumor/genéticaRESUMO
OBJECTIVE: Brain-derived neurotrophic factor (BDNF) has important roles in neural cell growth and differentiation. Despite multiple lines of evidence suggesting BDNF as a possible contributor to the pathogenesis of bipolar disorder (BD), the results of genetic association studies have been mixed. We hypothesize that BDNF gene polymorphisms may confer increased susceptibility to BD. METHODS: Using a cohort of multiplex bipolar families, we performed family-based association testing to look for associations between BD and eight single nucleotide polymorphisms (SNPs) from BDNF. RESULTS: We found associations (p < 0.05) between BD and six of the eight SNPs analysed, including two SNPs not previously investigated in association studies. We were able to replicate associations previously found between BD and the Val66Met polymorphism of BDNF (rs6265) and the SNPs rs1519480 and rs12273363. We also found evidence of an association between rs11030107 and BD that was not found in a previous study. CONCLUSIONS: Our results support the hypothesis that some BDNF gene polymorphisms may be contributing factors in the pathogenesis of BD. Our study also adds to the body of evidence associating the functional Val66Met polymorphism of BDNF with BD.
Assuntos
Transtorno Bipolar/genética , Fator Neurotrófico Derivado do Encéfalo/genética , Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único/genética , Estudos de Coortes , Feminino , Frequência do Gene , Estudos de Associação Genética , Genótipo , Humanos , Desequilíbrio de Ligação , Masculino , Metionina/genética , Valina/genética , População BrancaRESUMO
Spondylocarpotarsal synostosis syndrome (SCT) is characterized by vertebral fusions, a disproportionately short stature, and synostosis of carpal and tarsal bones. Pathogenic variants in FLNB, MYH3, and possibly in RFLNA, have been reported to be responsible for this condition. Here, we present two unrelated individuals presenting with features typical of SCT in which Sanger sequencing combined with whole genome sequencing identified novel, homozygous intragenic deletions in FLNB (c.1346-1372_1941+389del and c.3127-353_4223-1836del). Both deletions remove several consecutive exons and are predicted to result in a frameshift. To our knowledge, this is the first time that large structural variants in FLNB have been reported in SCT, and thus our findings add to the classes of variation that can lead to this disorder. These cases highlight the need for copy number sensitive methods to be utilized in order to be comprehensive in the search for a molecular diagnosis in individuals with a clinical diagnosis of SCT.
Assuntos
Anormalidades Múltiplas/etiologia , Filaminas/genética , Deleção de Genes , Vértebras Lombares/anormalidades , Doenças Musculoesqueléticas/etiologia , Mutação , Escoliose/congênito , Sinostose/etiologia , Vértebras Torácicas/anormalidades , Anormalidades Múltiplas/patologia , Adulto , Criança , Feminino , Humanos , Vértebras Lombares/patologia , Masculino , Doenças Musculoesqueléticas/patologia , Linhagem , Escoliose/etiologia , Escoliose/patologia , Síndrome , Sinostose/patologia , Vértebras Torácicas/patologiaRESUMO
Germline pathogenic variants in AMER1 cause osteopathia striata with cranial sclerosis (OSCS: OMIM 300373), an X-linked sclerosing bone disorder. Female heterozygotes exhibit metaphyseal striations in long bones, macrocephaly, cleft palate, and, occasionally, learning disability. Male hemizygotes typically manifest the condition as fetal or neonatal death. Somatically acquired variants in AMER1 are found in neoplastic tissue in 15-30% of patients with Wilms tumor; however, to date, only one individual with OSCS has been reported with a Wilms tumor. Here we present four cases of Wilms tumor in unrelated individuals with OSCS, including the single previously published case. We also report the first case of bilateral Wilms tumor in a patient with OSCS. Tumor tissue analysis showed no clear pattern of histological subtypes. In Beckwith-Wiedemann syndrome, which has a known predisposition to Wilms tumor development, clinical protocols have been developed for tumor surveillance. In the absence of further evidence, we propose a similar protocol for patients with OSCS to be instituted as an initial precautionary approach to tumor surveillance. Further evidence is needed to refine this protocol and to evaluate the possibility of development of other neoplasms later in life, in patients with OSCS.
Assuntos
Osteosclerose/genética , Fenótipo , Tumor de Wilms/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Pré-Escolar , Feminino , Mutação em Linhagem Germinativa , Humanos , Lactente , Osteosclerose/complicações , Osteosclerose/patologia , Proteínas Supressoras de Tumor/genética , Tumor de Wilms/etiologia , Tumor de Wilms/patologia , Adulto JovemRESUMO
Connective tissue disorders are a spectrum of diseases that affect the integrity of tissues including skin, vasculature, and joints. They are often caused by variants that disrupt genes encoding components of extracellular matrix (ECM). The fibulin glycoproteins are ECM proteins important for integrity of tissues including dermis, retina, fascia, and vasculature. The fibulin family consists of seven members (fibulins-1 to -7) and is defined by a fibulin-type domain at the C-terminus. The family is associated with human diseases, for instance a variant in FBLN1, encoding fibulin-1, is associated with synpolydactyly, while one in EFEMP1, encoding fibulin-3, causes Doyne honeycomb degeneration of the retina. Loss-of-function of fibulins-4 and -5 causes cutis laxa, while variants in fibulins-5 and -6 are associated with age-related macular degeneration. Of note, EFEMP1 is not currently associated with any connective tissue disorder. Here we show biallelic loss-of-function variants in EFEMP1 in an individual with multiple and recurrent abdominal and thoracic herniae, myopia, hypermobile joints, scoliosis, and thin translucent skin. Fibroblasts from this individual express significantly lower EFEMP1 transcript than age-matched control cells. A skin biopsy, visualised using light microscopy, showed normal structure and abundance of elastic fibres. The phenotype of this individual is remarkably similar to the Efemp1 knockout mouse model that displays multiple herniae with premature aging and scoliosis. We conclude that loss of EFEMP1 function in this individual is the cause of a connective tissue disorder with a novel combination of phenotypic features, and can perhaps explain similar, previously reported cases in the literature.
Assuntos
Doenças do Tecido Conjuntivo/genética , Proteínas da Matriz Extracelular/genética , Mutação com Perda de Função , Fenótipo , Adulto , Alelos , Células Cultivadas , Doenças do Tecido Conjuntivo/patologia , Proteínas da Matriz Extracelular/metabolismo , Humanos , MasculinoRESUMO
Osteopathia striata with cranial sclerosis (OSCS) is an X-linked dominant condition characterised by metaphyseal striations, macrocephaly, cleft palate, and developmental delay in affected females. Males have a more severe phenotype with multi-organ malformations, and rarely survive. To date, only frameshift and nonsense variants in exon 2, the single coding exon of AMER1, or whole gene deletions have been reported to cause OSCS. In this study, we describe two families with phenotypic features typical of OSCS. Exome sequencing and multiplex ligation-dependent probe amplification (MLPA) did not identify pathogenic variants in AMER1. Therefore, genome sequencing was employed which identified two deletions containing the non-coding exon 1 of AMER1 in the families. These families highlight the importance of considering variants or deletions of upstream non-coding exons in conditions such as OSCS, noting that often such exons are not captured on probe or enrichment-based platforms because of their high G/C content.