Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
1.
Nat Commun ; 15(1): 1210, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38331934

RESUMO

We implicated the X-chromosome THOC2 gene, which encodes the largest subunit of the highly-conserved TREX (Transcription-Export) complex, in a clinically complex neurodevelopmental disorder with intellectual disability as the core phenotype. To study the molecular pathology of this essential eukaryotic gene, we generated a mouse model based on a hypomorphic Thoc2 exon 37-38 deletion variant of a patient with ID, speech delay, hypotonia, and microcephaly. The Thoc2 exon 37-38 deletion male (Thoc2Δ/Y) mice recapitulate the core phenotypes of THOC2 syndrome including smaller size and weight, and significant deficits in spatial learning, working memory and sensorimotor functions. The Thoc2Δ/Y mouse brain development is significantly impacted by compromised THOC2/TREX function resulting in R-loop accumulation, DNA damage and consequent cell death. Overall, we suggest that perturbed R-loop homeostasis, in stem cells and/or differentiated cells in mice and the patient, and DNA damage-associated functional alterations are at the root of THOC2 syndrome.


Assuntos
Deficiência Intelectual , Fatores de Transcrição , Humanos , Masculino , Camundongos , Animais , Fatores de Transcrição/metabolismo , Estruturas R-Loop , Transporte Ativo do Núcleo Celular , Deficiência Intelectual/genética , Dano ao DNA , Fenótipo , RNA Mensageiro/metabolismo
2.
Brain ; 146(12): 5086-5097, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37977818

RESUMO

Stuttering is a common speech disorder that interrupts speech fluency and tends to cluster in families. Typically, stuttering is characterized by speech sounds, words or syllables which may be repeated or prolonged and speech that may be further interrupted by hesitations or 'blocks'. Rare variants in a small number of genes encoding lysosomal pathway proteins have been linked to stuttering. We studied a large four-generation family in which persistent stuttering was inherited in an autosomal dominant manner with disruption of the cortico-basal-ganglia-thalamo-cortical network found on imaging. Exome sequencing of three affected family members revealed the PPID c.808C>T (p.Pro270Ser) variant that segregated with stuttering in the family. We generated a Ppid p.Pro270Ser knock-in mouse model and performed ex vivo imaging to assess for brain changes. Diffusion-weighted MRI in the mouse revealed significant microstructural changes in the left corticospinal tract, as previously implicated in stuttering. Quantitative susceptibility mapping also detected changes in cortico-striatal-thalamo-cortical loop tissue composition, consistent with findings in affected family members. This is the first report to implicate a chaperone protein in the pathogenesis of stuttering. The humanized Ppid murine model recapitulates network findings observed in affected family members.


Assuntos
Gagueira , Humanos , Animais , Camundongos , Gagueira/genética , Gagueira/patologia , Fala , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Mapeamento Encefálico
3.
Genes (Basel) ; 14(8)2023 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-37628618

RESUMO

Aicardi Syndrome (AIC) is a rare neurodevelopmental disorder recognized by the classical triad of agenesis of the corpus callosum, chorioretinal lacunae and infantile epileptic spasms syndrome. The diagnostic criteria of AIC were revised in 2005 to include additional phenotypes that are frequently observed in this patient group. AIC has been traditionally considered as X-linked and male lethal because it almost exclusively affects females. Despite numerous genetic and genomic investigations on AIC, a unifying X-linked cause has not been identified. Here, we performed exome and genome sequencing of 10 females with AIC or suspected AIC based on current criteria. We identified a unique de novo variant, each in different genes: KMT2B, SLF1, SMARCB1, SZT2 and WNT8B, in five of these females. Notably, genomic analyses of coding and non-coding single nucleotide variants, short tandem repeats and structural variation highlighted a distinct lack of X-linked candidate genes. We assessed the likely pathogenicity of our candidate autosomal variants using the TOPflash assay for WNT8B and morpholino knockdown in zebrafish (Danio rerio) embryos for other candidates. We show expression of Wnt8b and Slf1 are restricted to clinically relevant cortical tissues during mouse development. Our findings suggest that AIC is genetically heterogeneous with implicated genes converging on molecular pathways central to cortical development.


Assuntos
Síndrome de Aicardi , Masculino , Feminino , Animais , Camundongos , Síndrome de Aicardi/genética , Peixe-Zebra/genética , Mapeamento Cromossômico , Genes Ligados ao Cromossomo X/genética , Bioensaio
4.
Epilepsia ; 64 Suppl 1: S14-S21, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37021642

RESUMO

Familial adult myoclonus epilepsy (FAME) is a genetic epilepsy syndrome that for many years has resisted understanding of its underlying molecular cause. This review covers the history of FAME genetic studies worldwide, starting with linkage and culminating in the discovery of noncoding TTTTA and inserted TTTCA pentanucleotide repeat expansions within six different genes to date (SAMD12, STARD7, MARCHF6, YEATS2, TNRC6A, and RAPGEF2). FAME occurs worldwide; however, repeat expansions in particular genes have regional geographical distributions. FAME repeat expansions are dynamic in nature, changing in length and structure within germline and somatic tissues. This variation poses challenges for molecular diagnosis such that molecular methods used to identify FAME repeat expansions typically require a trade-off between cost and efficiency. A rigorous evaluation of the sensitivity and specificity of each molecular approach remains to be performed. The origin of FAME repeat expansions and the genetic and environmental factors that modulate repeat variability are not well defined. Longer repeats and particular arrangements of the TTTTA and TTTCA motifs within an expansion are correlated with earlier onset and increased severity of disease. Other factors such as maternal or paternal inheritance, parental age, and repeat length alone have been suggested to influence repeat variation; however, further research is required to confirm this. The history of FAME genetics to the present is a chronicle of perseverance and predominantly collaborative efforts that yielded a successful outcome. The discovery of FAME repeats will spark progress toward a deeper understanding of the molecular pathogenesis of FAME, discovery of new loci, and development of cell and animal models.


Assuntos
Epilepsias Mioclônicas , Humanos , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/patologia , Linhagem , Pesquisa
5.
Epilepsia ; 64 Suppl 1: S31-S38, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36622139

RESUMO

Familial adult myoclonus epilepsy (FAME) results from the same pathogenic TTTTA/TTTCA pentanucleotide repeat expansion in six distinct genes encoding proteins with different subcellular localizations and very different functions, which poses the issue of what causes the neurobiological disturbances that lead to the clinical phenotype. Postmortem and electrophysiological studies have pointed to cortical hyperexcitability as well as dysfunction and neurodegeneration of both the cortex and cerebellum of FAME subjects. FAME expansions, contrary to the same expansion in DAB1 causing spinocerebellar ataxia type 37, seem to have no or limited impact on their recipient gene expression, which suggests a pathophysiological mechanism independent of the gene and its function. Current hypotheses include toxicity of the RNA molecules carrying UUUCA repeats, or toxicity of polypeptides encoded by the repeats, a mechanism known as repeat-associated non-AUG translation. The analysis of postmortem brains of FAME1 expansion (in SAMD12) carriers has revealed the presence of RNA foci that could be formed by the aggregation of RNA molecules with abnormal UUUCA repeats, but evidence is still lacking for other FAME subtypes. Even when the expansion is located in a gene ubiquitously expressed, expression of repeats remains undetectable in peripheral tissues (blood, skin). Therefore, the development of appropriate cellular models (induced pluripotent stem cell-derived neurons) or the study of affected tissues in patients is required to elucidate how FAME repeat expansions located in unrelated genes lead to disease.


Assuntos
Excitabilidade Cortical , Epilepsias Mioclônicas , Humanos , Íntrons , Repetições de Microssatélites , RNA
6.
Aerosp Med Hum Perform ; 93(4): 354-361, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35354514

RESUMO

INTRODUCTION: Pilot fatigue is a significant concern in aviation, where efforts are directed at improving rosters, developing models, and improving countermeasures. Little attention has been given to in-flight detection of fatigue/drowsiness. The aims of this research were to determine whether drowsiness is an issue and explore whether infrared reflectance oculography could prove useful for continuous inflight monitoring.METHODS: Nine university-based pilot trainees wore activity monitors and completed diaries, prior to a simulated navigational exercise of approximately 4 h, during the secondary window of circadian low. During the flight they wore a head-mounted device. Oculographic data were collected and converted into a single number, using the Johns Drowsiness Scale (JDS), with increasing values indicating greater drowsiness (range 0.0 to 10.0).RESULTS: Peak JDS values reached 6.5. Values declined from shortly before top of descent, continuing until landing. Two of the nine participants (22.2%), reached drowsiness levels at or above a cautionary warning level, below which is considered safe for driving a motor vehicle.DISCUSSION: The results of this study revealed the timeline and levels of fatigue that might be experienced by student pilots; showing that drowsiness is a potential issue for student pilots operating in flying conditions similar to those in the simulation. Analysis indicated that pilots are likely to experience levels of drowsiness above a cautionary warning level when modeling predicted effectiveness below 90%, indicating a potential drowsiness issue for pilots. It was concluded that oculography is worthy of further investigation for use as an objective fatigue detection tool in aviation.Corbett MA, Newman DG. Student drowsiness during simulated solo flight. Aerosp Med Hum Perform. 2022; 93(4):354-361.


Assuntos
Acidentes Aeronáuticos , Aviação , Atenção , Humanos , Estudantes , Vigília
7.
Neurol Genet ; 8(1): e652, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35097204

RESUMO

BACKGROUND AND OBJECTIVES: The 2-hit model of genetic disease is well established in cancer, yet has only recently been reported to cause brain malformations associated with epilepsy. Pathogenic germline and somatic variants in genes in the mechanistic target of rapamycin (mTOR) pathway have been implicated in several malformations of cortical development. We investigated the 2-hit model by performing genetic analysis and searching for germline and somatic variants in genes in the mTOR and related pathways. METHODS: We searched for germline and somatic pathogenic variants in 2 brothers with drug-resistant focal epilepsy and surgically resected focal cortical dysplasia (FCD) type IIA. Exome sequencing was performed on blood- and brain-derived DNA to identify pathogenic variants, which were validated by droplet digital PCR. In vitro functional assays of a somatic variant were performed. RESULTS: Exome analysis revealed a novel, maternally inherited, germline pathogenic truncation variant (c.48delG; p.Ser17Alafs*70) in NPRL3 in both brothers. NPRL3 is a known FCD gene that encodes a negative regulator of the mTOR pathway. Somatic variant calling in brain-derived DNA from both brothers revealed a low allele fraction somatic variant (c.338C>T; p.Ala113Val) in the WNT2 gene in 1 brother, confirmed by droplet digital PCR. In vitro functional studies suggested a loss of WNT2 function as a consequence of this variant. A second somatic variant has not yet been found in the other brother. DISCUSSION: We identify a pathogenic germline mTOR pathway variant (NPRL3) and a somatic variant (WNT2) in the intersecting WNT signaling pathway, potentially implicating the WNT2 gene in FCD and supporting a dual-pathway 2-hit model. If confirmed in other cases, this would extend the 2-hit model to pathogenic variants in different genes in critical, intersecting pathways in a malformation of cortical development. Detection of low allele fraction somatic second hits is challenging but promises to unravel the molecular architecture of FCDs.

8.
NPJ Genom Med ; 7(1): 9, 2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35091571

RESUMO

TIMMDC1 encodes the Translocase of Inner Mitochondrial Membrane Domain-Containing protein 1 (TIMMDC1) subunit of complex I of the electron transport chain responsible for ATP production. We studied a consanguineous family with two affected children, now deceased, who presented with failure to thrive in the early postnatal period, poor feeding, hypotonia, peripheral neuropathy and drug-resistant epilepsy. Genome sequencing data revealed a known, deep intronic pathogenic variant TIMMDC1 c.597-1340A>G, also present in gnomAD (~1/5000 frequency), that enhances aberrant splicing. Using RNA and protein analysis we show almost complete loss of TIMMDC1 protein and compromised mitochondrial complex I function. We have designed and applied two different splice-switching antisense oligonucleotides (SSO) to restore normal TIMMDC1 mRNA processing and protein levels in patients' cells. Quantitative proteomics and real-time metabolic analysis of mitochondrial function on patient fibroblasts treated with SSOs showed restoration of complex I subunit abundance and function. SSO-mediated therapy of this inevitably fatal TIMMDC1 neurologic disorder is an attractive possibility.

9.
Exp Eye Res ; 210: 108692, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34228965

RESUMO

Fuchs' endothelial corneal dystrophy (FECD) is a progressive vision impairing disease caused by thickening of Descemet's membrane and gradual degeneration and loss of corneal endothelial cells. The aim of this study was to identify differentially expressed genes between FECD-affected and unaffected corneal endothelium to gain insight into the pathophysiological mechanisms underlying this disease. Microarray gene expression analysis was performed on total RNA from FECD-affected and unaffected corneal endothelium-Descemet's membrane (CE-DM) specimens using the Illumina HumanHT-12 v4.0 expression array. RNA from pools of FECD-affected (n = 3 per pool) and individual unaffected (n = 3) specimens was used for comparison. Altered expression of a sub-set of differentially expressed genes was validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in independent specimens. Bioinformatics analysis was performed using InnateDB to reveal functional relationships among the differentially expressed genes and molecular pathways involved in the disease. A total of 16,513 genes were found expressed in the corneal endothelium of which 142 genes were differentially expressed between FECD-affected and unaffected endothelium (log2 fold-change ≥1.5, corrected p-value ≤0.05). Most of the genes were up-regulated (126) and a small proportion down-regulated (16) in affected corneal endothelium. Of the twelve genes prioritised for validation, differential expression of 10 genes, including those ranked 57th and 81st by significance validated by qRT-PCR (8 up-regulated and 2 downregulated, corrected p ≤ 0.05), one gene showed a trend for up-regulation in affected endothelium, consistent with the microarray analysis and another was up-regulated in an independent study indicating robustness of the differential expression dataset. Bioinformatic analysis revealed significant over-representation of differentially expressed genes in extracellular matrix reorganisation, cellular remodelling, immune response, and inflammation. Network analysis showed functional inter-relatedness of the majority of the dysregulated genes and revealed known direct functional relationships between 20 of the genes; many of these genes have roles in macrophage differentiation, phagocytosis and inflammation. This is the second report of microarray gene expression analysis in FECD. This study revealed a set of highly dysregulated genes in the corneal endothelium in FECD. More than a third of the dysregulated genes in the disease have been discovered for the first time and thus are novel. The dysregulated genes strongly suggest the presence of phagocytic cells, most likely immune cells, and inflammation in corneal endothelium in the disease. This study provides a molecular framework for delineating the mechanisms underlying these cellular processes in FECD.


Assuntos
Endotélio Corneano/metabolismo , Proteínas do Olho/genética , Distrofia Endotelial de Fuchs/genética , Regulação da Expressão Gênica/fisiologia , Fagócitos/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Feminino , Distrofia Endotelial de Fuchs/fisiopatologia , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Análise Serial de Proteínas , RNA/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real
10.
Hum Mutat ; 42(8): 1030-1041, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34082468

RESUMO

PCDH19 is a nonclustered protocadherin molecule involved in axon bundling, synapse function, and transcriptional coregulation. Pathogenic variants in PCDH19 cause infantile-onset epilepsy known as PCDH19-clustering epilepsy or PCDH19-CE. Recent advances in DNA-sequencing technologies have led to a significant increase in the number of reported PCDH19-CE variants, many of uncertain significance. We aimed to determine the best approaches for assessing the disease relevance of missense variants in PCDH19. The application of the American College of Medical Genetics and Association for Molecular Pathology (ACMG-AMP) guidelines was only 50% accurate. Using a training set of 322 known benign or pathogenic missense variants, we identified MutPred2, MutationAssessor, and GPP as the best performing in silico tools. We generated a protein structural model of the extracellular domain and assessed 24 missense variants. We also assessed 24 variants using an in vitro reporter assay. A combination of these tools was 93% accurate in assessing known pathogenic and benign PCDH19 variants. We increased the accuracy of the ACMG-AMP classification of 45 PCDH19 variants from 50% to 94%, using these tools. In summary, we have developed a robust toolbox for the assessment of PCDH19 variant pathogenicity to improve the accuracy of PCDH19-CE variant classification.


Assuntos
Caderinas , Epilepsia , Caderinas/genética , Humanos , Mutação de Sentido Incorreto , Protocaderinas , Análise de Sequência de DNA
11.
Neurology ; 96(18): e2251-e2260, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-34038384

RESUMO

OBJECTIVE: To identify the causative gene in a large unsolved family with genetic epilepsy with febrile seizures plus (GEFS+), we sequenced the genomes of family members, and then determined the contribution of the identified gene to the pathogenicity of epilepsies by examining sequencing data from 2,772 additional patients. METHODS: We performed whole genome sequencing of 3 members of a GEFS+ family. Subsequently, whole exome sequencing data from 1,165 patients with epilepsy from the Epi4K dataset and 1,329 Australian patients with epilepsy from the Epi25 dataset were interrogated. Targeted resequencing was performed on 278 patients with febrile seizures or GEFS+ phenotypes. Variants were validated and familial segregation examined by Sanger sequencing. RESULTS: Eight previously unreported missense variants were identified in SLC32A1, coding for the vesicular inhibitory amino acid cotransporter VGAT. Two variants cosegregated with the phenotype in 2 large GEFS+ families containing 8 and 10 affected individuals, respectively. Six further variants were identified in smaller families with GEFS+ or idiopathic generalized epilepsy (IGE). CONCLUSION: Missense variants in SLC32A1 cause GEFS+ and IGE. These variants are predicted to alter γ-aminobutyric acid (GABA) transport into synaptic vesicles, leading to altered neuronal inhibition. Examination of further epilepsy cohorts will determine the full genotype-phenotype spectrum associated with SLC32A1 variants.


Assuntos
Epilepsia Generalizada/diagnóstico , Epilepsia Generalizada/genética , Variação Genética/genética , Mutação de Sentido Incorreto/genética , Convulsões Febris/diagnóstico , Convulsões Febris/genética , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores/genética , Feminino , Estudos de Associação Genética/métodos , Humanos , Masculino , Linhagem
12.
Eur J Hum Genet ; 29(8): 1206-1215, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33867527

RESUMO

Inherited paediatric cataract is a rare Mendelian disease that results in visual impairment or blindness due to a clouding of the eye's crystalline lens. Here we report an Australian family with isolated paediatric cataract, which we had previously mapped to Xq24. Linkage at Xq24-25 (LOD = 2.53) was confirmed, and the region refined with a denser marker map. In addition, two autosomal regions with suggestive evidence of linkage were observed. A segregating 127 kb deletion (chrX:g.118373226_118500408del) in the Xq24-25 linkage region was identified from whole-genome sequencing data. This deletion completely removed a commonly deleted long non-coding RNA gene LOC101928336 and truncated the protein coding progesterone receptor membrane component 1 (PGRMC1) gene following exon 1. A literature search revealed a report of two unrelated males with non-syndromic intellectual disability, as well as congenital cataract, who had contiguous gene deletions that accounted for their intellectual disability but also disrupted the PGRMC1 gene. A morpholino-induced pgrmc1 knockdown in a zebrafish model produced significant cataract formation, supporting a role for PGRMC1 in lens development and cataract formation. We hypothesise that the loss of PGRMC1 causes cataract through disrupted PGRMC1-CYP51A1 protein-protein interactions and altered cholesterol biosynthesis. The cause of paediatric cataract in this family is the truncating deletion of PGRMC1, which we report as a novel cataract gene.


Assuntos
Catarata/genética , Proteínas de Membrana/genética , Receptores de Progesterona/genética , Animais , Catarata/metabolismo , Catarata/patologia , Criança , Deleção de Genes , Humanos , Masculino , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Linhagem , Ligação Proteica , Receptores de Progesterona/química , Receptores de Progesterona/metabolismo , Esterol 14-Desmetilase/metabolismo , Peixe-Zebra
13.
Hum Mutat ; 42(7): 835-847, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33847015

RESUMO

The pioneering discovery research of X-linked intellectual disability (XLID) genes has benefitted thousands of individuals worldwide; however, approximately 30% of XLID families still remain unresolved. We postulated that noncoding variants that affect gene regulation or splicing may account for the lack of a genetic diagnosis in some cases. Detecting pathogenic, gene-regulatory variants with the same sensitivity and specificity as structural and coding variants is a major challenge for Mendelian disorders. Here, we describe three pedigrees with suggestive XLID where distinctive phenotypes associated with known genes guided the identification of three different noncoding variants. We used comprehensive structural, single-nucleotide, and repeat expansion analyses of genome sequencing. RNA-Seq from patient-derived cell lines, reverse-transcription polymerase chain reactions, Western blots, and reporter gene assays were used to confirm the functional effect of three fundamentally different classes of pathogenic noncoding variants: a retrotransposon insertion, a novel intronic splice donor, and a canonical splice variant of an untranslated exon. In one family, we excluded a rare coding variant in ARX, a known XLID gene, in favor of a regulatory noncoding variant in OFD1 that correlated with the clinical phenotype. Our results underscore the value of genomic research on unresolved XLID families to aid novel, pathogenic noncoding variant discovery.


Assuntos
Deficiência Intelectual , Expressão Gênica , Genes Ligados ao Cromossomo X , Genômica , Humanos , Deficiência Intelectual/diagnóstico , Linhagem
14.
Hum Mol Genet ; 30(7): 575-594, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33772537

RESUMO

The PHF6 mutation c.1024C > T; p.R342X, is a recurrent cause of Börjeson-Forssman-Lehmann Syndrome (BFLS), a neurodevelopmental disorder characterized by moderate-severe intellectual disability, truncal obesity, gynecomastia, hypogonadism, long tapering fingers and large ears (MIM#301900). Here, we generated transgenic mice with the identical substitution (R342X mice) using CRISPR technology. We show that the p.R342X mutation causes a reduction in PHF6 protein levels, in both human and mice, from nonsense-mediated decay and nonsense-associated alternative splicing, respectively. Magnetic resonance imaging studies indicated that R342X mice had a reduced brain volume on a mixed genetic background but developed hydrocephaly and a high incidence of postnatal death on a C57BL/6 background. Cortical development proceeded normally, while hippocampus and hypothalamus relative brain volumes were altered. A hypoplastic anterior pituitary was also observed that likely contributes to the small size of the R342X mice. Behavior testing demonstrated deficits in associative learning, spatial memory and an anxiolytic phenotype. Taken together, the R342X mice represent a good preclinical model of BFLS that will allow further dissection of PHF6 function and disease pathogenesis.


Assuntos
Modelos Animais de Doenças , Epilepsia/genética , Face/anormalidades , Dedos/anormalidades , Predisposição Genética para Doença/genética , Transtornos do Crescimento/genética , Hipogonadismo/genética , Retardo Mental Ligado ao Cromossomo X/genética , Mutação , Obesidade/genética , Proteínas Repressoras/genética , Animais , Aprendizagem por Associação/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Epilepsia/metabolismo , Epilepsia/fisiopatologia , Face/fisiopatologia , Feminino , Dedos/fisiopatologia , Perfilação da Expressão Gênica/métodos , Transtornos do Crescimento/metabolismo , Transtornos do Crescimento/fisiopatologia , Humanos , Hipogonadismo/metabolismo , Hipogonadismo/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Masculino , Retardo Mental Ligado ao Cromossomo X/metabolismo , Retardo Mental Ligado ao Cromossomo X/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Obesidade/metabolismo , Obesidade/fisiopatologia , RNA-Seq/métodos , Proteínas Repressoras/metabolismo , Memória Espacial/fisiologia
16.
NPJ Genom Med ; 5(1): 53, 2020 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-33298948

RESUMO

USP9X is an X-chromosome gene that escapes X-inactivation. Loss or compromised function of USP9X leads to neurodevelopmental disorders in males and females. While males are impacted primarily by hemizygous partial loss-of-function missense variants, in females de novo heterozygous complete loss-of-function mutations predominate, and give rise to the clinically recognisable USP9X-female syndrome. Here we provide evidence of the contribution of USP9X missense and small in-frame deletion variants in USP9X-female syndrome also. We scrutinise the pathogenicity of eleven such variants, ten of which were novel. Combined application of variant prediction algorithms, protein structure modelling, and assessment under clinically relevant guidelines universally support their pathogenicity. The core phenotype of this cohort overlapped with previous descriptions of USP9X-female syndrome, but exposed heightened variability. Aggregate phenotypic information of 35 currently known females with predicted pathogenic variation in USP9X reaffirms the clinically recognisable USP9X-female syndrome, and highlights major differences when compared to USP9X-male associated neurodevelopmental disorders.

17.
Nat Genet ; 52(10): 1046-1056, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32989326

RESUMO

In addition to commonly associated environmental factors, genomic factors may cause cerebral palsy. We performed whole-exome sequencing of 250 parent-offspring trios, and observed enrichment of damaging de novo mutations in cerebral palsy cases. Eight genes had multiple damaging de novo mutations; of these, two (TUBA1A and CTNNB1) met genome-wide significance. We identified two novel monogenic etiologies, FBXO31 and RHOB, and showed that the RHOB mutation enhances active-state Rho effector binding while the FBXO31 mutation diminishes cyclin D levels. Candidate cerebral palsy risk genes overlapped with neurodevelopmental disorder genes. Network analyses identified enrichment of Rho GTPase, extracellular matrix, focal adhesion and cytoskeleton pathways. Cerebral palsy risk genes in enriched pathways were shown to regulate neuromotor function in a Drosophila reverse genetics screen. We estimate that 14% of cases could be attributed to an excess of damaging de novo or recessive variants. These findings provide evidence for genetically mediated dysregulation of early neuronal connectivity in cerebral palsy.


Assuntos
Paralisia Cerebral/genética , Proteínas F-Box/genética , Tubulina (Proteína)/genética , Proteínas Supressoras de Tumor/genética , beta Catenina/genética , Animais , Paralisia Cerebral/patologia , Ciclina D/genética , Citoesqueleto/genética , Drosophila/genética , Exoma/genética , Matriz Extracelular/genética , Feminino , Adesões Focais/genética , Predisposição Genética para Doença , Genoma Humano/genética , Humanos , Masculino , Mutação/genética , Neuritos/metabolismo , Neuritos/patologia , Fatores de Risco , Análise de Sequência de DNA , Transdução de Sinais/genética , Sequenciamento do Exoma , Proteína rhoB de Ligação ao GTP/genética
18.
Dev Med Child Neurol ; 62(9): 1024-1030, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32542675

RESUMO

AIM: To conduct a systematic review of phenotypic definition and case ascertainment in published genetic studies of cerebral palsy (CP) to inform guidelines for the reporting of such studies. METHOD: Inclusion criteria comprised genetic studies of candidate genes, with CP as the outcome, published between 1990 and 2019 in the PubMed, Embase, and BIOSIS Citation Index databases. RESULTS: Fifty-seven studies met the inclusion criteria. We appraised how CP was defined, the quality of information on case ascertainment, and compliance with international consensus guidelines. Seven studies (12%) were poorly described, 33 studies (58%) gave incomplete information, and 17 studies (30%) were well described. Missing key information precluded determining how many studies complied with the definition by Rosenbaum et al. Only 18 out of 57 studies (32%) were compliant with the Surveillance of Cerebral Palsy in Europe (SCPE) international guidelines on defining CP. INTERPRETATION: Limited compliance with international consensus guidelines on phenotypic definition and mediocre reporting of CP case ascertainment hinders the comparison of results among genetic studies of CP (including meta-analyses), thereby limiting the quality, interpretability, and generalizability of study findings. Compliance with the SCPE guidelines is important for ongoing gene discovery efforts in CP, given the potential for misclassification of unrelated neurological conditions as CP.


Assuntos
Paralisia Cerebral/diagnóstico , Paralisia Cerebral/genética , Consenso , Bases de Dados Factuais , Guias como Assunto , Humanos , Fenótipo , Vigilância da População , Sistema de Registros
19.
Eur J Hum Genet ; 28(7): 973-978, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32203200

RESUMO

Familial adult myoclonic epilepsy 1 (FAME1), first recognised in Japanese families, was recently shown to be caused by a TTTCA repeat insertion in intron 4 of SAMD12 on chromosome 8. We performed whole genome sequencing on two families with FAME, one of Sri Lankan origin and the other of Indian origin, and identified a TTTCA repeat insertion in SAMD12 in both families. Haplotype analysis revealed that both families shared the same core ancestral haplotype reported in Japanese and Chinese families with FAME1. Mutation dating, based on the length of shared haplotypes, estimated the age of the ancestral haplotype to be ~670 generations, or 17,000 years old. Our data extend the geographic range of this repeat expansion to Southern Asia and potentially implicate an even broader regional distribution given the age of the variant. This finding suggests patients of Asian ancestry with suspected FAME should be screened for the SAMD12 TTTCA expansion.


Assuntos
Epilepsias Mioclônicas/genética , Efeito Fundador , Proteínas do Tecido Nervoso/genética , Feminino , Haplótipos , Humanos , Índia , Masculino , Mutação , Linhagem , Sri Lanka
20.
Cell Rep ; 30(11): 3717-3728.e6, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32187544

RESUMO

Understanding the mechanisms of activity-dependent gene transcription underlying adaptive behaviors is challenging at neuronal-subtype resolution. Using cell-type specific molecular analysis in agouti-related peptide (AgRP) neurons, we reveal that the profound hunger-induced transcriptional changes greatly depend on plant homeodomain finger protein 6 (PHF6), a transcriptional repressor enriched in AgRP neurons. Loss of PHF6 in the satiated mice results in a hunger-state-shifting transcriptional profile, while hunger fails to further induce a rapid and robust activity-dependent gene transcription in PHF6-deficient AgRP neurons. We reveal that PHF6 binds to the promoters of a subset of immediate-early genes (IEGs) and that this chromatin binding is dynamically regulated by hunger state. Depletion of PHF6 decreases hunger-driven feeding motivation and makes the mice resistant to body weight gain under repetitive fasting-refeeding conditions. Our work identifies a neuronal subtype-specific transcriptional repressor that modulates transcriptional profiles in different nutritional states and enables adaptive eating behavior.


Assuntos
Cromatina/metabolismo , Redes Reguladoras de Genes/genética , Fome/fisiologia , Neurônios/metabolismo , Proteínas Repressoras/metabolismo , Proteína Relacionada com Agouti/metabolismo , Animais , Dieta , Regulação para Baixo/genética , Comportamento Alimentar , Ontologia Genética , Genes Precoces , Hipotálamo/metabolismo , Camundongos Endogâmicos C57BL , Motivação , Regiões Promotoras Genéticas/genética , Ligação Proteica , Proteínas Repressoras/genética , Resposta de Saciedade , Aumento de Peso
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...