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1.
BMC Bioinformatics ; 21(1): 273, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32611382

RESUMO

BACKGROUND: Exome and genome sequencing is becoming the method of choice for rare disease diagnostics. One of the key challenges remaining is distinguishing the disease causing variants from the benign background variation. After analysis and annotation of the sequencing data there are typically thousands of candidate variants requiring further investigation. One of the most effective and least biased ways to reduce this number is to assess the rarity of a variant in any population. Currently, there are a number of reliable sources of information for major population frequencies when considering single nucleotide variants (SNVs) and small insertion and deletions (INDELs), with gnomAD as the most prominent public resource available. However, local variation or frequencies in sub-populations may be underrepresented in these public resources. In contrast, for structural variation (SV), the background frequency in the general population is more or less unknown mostly due to challenges in calling SVs in a consistent way. Keeping track of local variation is one way to overcome these problems and significantly reduce the number of potential disease causing variants retained for manual inspection, both for SNVs and SVs. RESULTS: Here, we present loqusdb, a tool to solve the challenge of keeping track of any type of variant observations from genome sequencing data. Loqusdb was designed to handle a large flow of samples and unlike other solutions, samples can be added continuously to the database without rebuilding it, facilitating improvements and additions. We assessed the added value of a local observations database using 98 samples annotated with information from a background of 888 unrelated individuals. CONCLUSIONS: We show both how powerful SV analysis can be when filtering for population frequencies and how the number of apparently rare SNVs/INDELs can be reduced by adding local population information even after annotating the data with other large frequency databases, such as gnomAD. In conclusion, we show that a local frequency database is an attractive, and a necessary addition to the publicly available databases that facilitate the analysis of exome and genome data in a clinical setting.


Assuntos
Variação Genética , Interface Usuário-Computador , Bases de Dados Genéticas , Humanos , Mutação INDEL , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Polimorfismo de Nucleotídeo Único
2.
Nat Commun ; 11(1): 3351, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620897

RESUMO

The sodium-leak channel NALCN forms a subthreshold sodium conductance that controls the resting membrane potentials of neurons. The auxiliary subunits of the channel and their functions in mammals are largely unknown. In this study, we demonstrate that two large proteins UNC80 and UNC79 are subunits of the NALCN complex. UNC80 knockout mice are neonatal lethal. The C-terminus of UNC80 contains a domain that interacts with UNC79 and overcomes a soma-retention signal to achieve dendritic localization. UNC80 lacking this domain, as found in human patients, still supports whole-cell NALCN currents but lacks dendritic localization. Our results establish the subunit composition of the NALCN complex, uncover the inter-subunit interaction domains, reveal the functional significance of regulation of dendritic membrane potential by the sodium-leak channel complex, and provide evidence supporting that genetic variations found in individuals with intellectual disability are the causes for the phenotype observed in patients.


Assuntos
Proteínas de Transporte/genética , Deficiência Intelectual/genética , Canais Iônicos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/genética , Animais , Proteínas de Transporte/metabolismo , Criança , Análise Mutacional de DNA , Conjuntos de Dados como Assunto , Dendritos/patologia , Modelos Animais de Doenças , Técnicas de Introdução de Genes , Células HEK293 , Hipocampo/citologia , Hipocampo/patologia , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/patologia , Canais Iônicos/genética , Masculino , Camundongos , Camundongos Knockout , Mutação , Proteínas do Tecido Nervoso/metabolismo , Cultura Primária de Células , Domínios Proteicos/genética , Índice de Gravidade de Doença , Sequenciamento Completo do Exoma
3.
BMC Med Genet ; 21(1): 93, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375772

RESUMO

BACKGROUND: Pathogenic SLC6A1 variants have been reported in patients with myoclonic-atonic epilepsy (MAE). NOTCH1, encoding a member of the Notch family of proteins, is known to be associated with aortic valve disease. The PRIMPOL variant has only been identified in Chinese patients with high myopia. Exome sequencing analysis now allows the simultaneous detection of multiple genetic etiologies for patients with complicated clinical features. However, the presence of three Mendelian disorders in one patient supported by their respective pathogenic variants and clinical phenotypes is very rare. CASE PRESENTATION: Here, we report a 4-year-old Chinese boy who presented with MAE, delayed language, borderline intellectual disability (ID), mildly impaired social skills and attention deficit hyperactivity disorder (ADHD). He also had mild aortic valve stenosis and high myopia. Using whole-exome sequencing (WES), we identified three variants: (1) SLC6A1, NM_003042.4: c.881-883del (p.Phe294del), (2) NOTCH1, NM_017617.5:c.1100-2A > G and (3) PRIMPOL, NM_152683.4:c.265 T > G (p.Tyr89Asp). Parental Sanger sequencing confirmed that SLC6A1 and NOTCH1 variants were de novo, whereas the PRIMPOL variant was inherited from the father who also had high myopia. Furthermore, the PRIMPOL variant was absent from the genomes of the paternal grandparents, and thus was also a de novo event in the family. All three variants are classified as pathogenic. CONCLUSION: The SLC6A1 variant could explain the features of MAE, delayed language, borderline ID, impaired social skills and ADHD in this patient, whereas the features of aortic valve stenosis and high myopia of the patient may be explained by variants in NOTCH1 and PRIMPOL, respectively. This case demonstrated the utility of exome sequencing in uncovering the multiple pathogenic variants in a patient with complicated phenotypes due to the blending of three Mendelian disorders.


Assuntos
Epilepsias Mioclônicas/genética , Epilepsia Generalizada/genética , Predisposição Genética para Doença , Miopia/genética , Estenose da Valva Aórtica/genética , Estenose da Valva Aórtica/patologia , Pré-Escolar , DNA Primase/genética , DNA Polimerase Dirigida por DNA/genética , Epilepsias Mioclônicas/patologia , Epilepsia Generalizada/patologia , Proteínas da Membrana Plasmática de Transporte de GABA/genética , Testes Genéticos , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Masculino , Enzimas Multifuncionais/genética , Mutação/genética , Miopia/patologia , Receptor Notch1/genética , Sequenciamento Completo do Exoma
4.
BMC Med Genet ; 21(1): 99, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393352

RESUMO

BACKGROUND: To date, at least 746 genes have been identified to cause intellectual disability (ID). Among them, mutations in the Methyl CpG binding protein 2 (MECP2) gene are the leading cause of Rett syndrome and associated ID. METHODS: Considering the large number of ID-associated genes, we applied trio-based whole-exome sequencing (trio-WES) and in silico analysis for genetic diagnosis of 294 children with ID. RESULTS: Three de novo heterozygous mutations [NM_004992.3: c.502C > T, p.(Arg168*), c.916C > T, p.(Arg306Cys), and c.879C > G, p.(Ile293Met)] in MECP2 were identified in three unrelated girls. The first two mutations were detected in two patients who were diagnosed as typical Rett syndrome, X-linked ID and psychomotor retardation. The third mutation (c.879C > G), a previously unreported, was found in a 6-year-old girl with ID, microcephaly, severe underweight and psychomotor retardation. Particularly, this extremely rare de novo mutation (DNM) is located in the transcriptional repression domain (TRD) of MECP2, where at least 62 different causal mutations are identified. CONCLUSIONS: We identified three DNMs in MECP2 in a cohort of 294 individuals with ID. The novel c.879C > G mutation, as a likely pathogenic allele, may become a risk factor associated with X-linked ID, microcephaly and psychomotor retardation.


Assuntos
Predisposição Genética para Doença , Deficiência Intelectual/genética , Proteína 2 de Ligação a Metil-CpG/genética , Síndrome de Rett/genética , Criança , Pré-Escolar , Feminino , Heterozigoto , Humanos , Deficiência Intelectual/patologia , Microcefalia/genética , Microcefalia/patologia , Mutação , Linhagem , Fenótipo , Síndrome de Rett/patologia , Sequenciamento Completo do Exoma
5.
Hum Genet ; 139(10): 1247-1259, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32306098

RESUMO

Congenital diarrheal disorders (CDD) comprise > 50 monogenic entities featuring chronic diarrhea of early-onset, including defects in nutrient and electrolyte absorption, enterocyte polarization, enteroendocrine cell differentiation, and epithelial integrity. Diarrhea is also a predominant symptom in many immunodeficiencies, congenital disorders of glycosylation, and in some defects of the vesicular sorting and transporting machinery. We set out to identify the etiology of an intractable diarrhea in 2 consanguineous families by whole-exome sequencing, and identified two novel AP1S1 mutations, c.269T>C (p.Leu90Pro) and c.346G>A (p.Glu116Lys). AP1S1 encodes the small subunit of the adaptor protein 1 complex (AP-1), which plays roles in clathrin coat-assembly and trafficking between trans-Golgi network, endosomes and the plasma membrane. An AP1S1 knock-out (KO) of a CaCo2 intestinal cell line was generated to characterize intestinal AP1S1 deficiency as well as identified mutations by stable expression in KO background. Morphology and prototype transporter protein distribution were comparable between parental and KO cells. We observed altered localization of tight-junction proteins ZO-1 and claudin 3, decreased transepithelial electrical resistance and an increased dextran permeability of the CaCo2-AP1S1-KO monolayer. In addition, lumen formation in 3D cultures of these cells was abnormal. Re-expression of wild-type AP1S1 in CaCo2-AP1S1-KO cells reverted these abnormalities, while expression of AP1S1 containing either missense mutation did not. Our data indicate that loss of AP1S1 function causes an intestinal epithelial barrier defect, and that AP1S1 mutations can cause a non-syndromic form of congenital diarrhea, whereas 2 reported truncating AP1S1 mutations caused MEDNIK syndrome, characterized by mental retardation, enteropathy, deafness, neuropathy, ichthyosis, and keratodermia.


Assuntos
Complexo 1 de Proteínas Adaptadoras/genética , Subunidades sigma do Complexo de Proteínas Adaptadoras/genética , Surdez/genética , Diarreia/genética , Ictiose/genética , Deficiência Intelectual/genética , Ceratodermia Palmar e Plantar/genética , Mutação de Sentido Incorreto , Complexo 1 de Proteínas Adaptadoras/deficiência , Subunidades sigma do Complexo de Proteínas Adaptadoras/deficiência , Sequência de Bases , Células CACO-2 , Claudina-3/genética , Claudina-3/metabolismo , Consanguinidade , Surdez/diagnóstico , Surdez/metabolismo , Surdez/patologia , Diarreia/diagnóstico , Diarreia/metabolismo , Diarreia/patologia , Feminino , Expressão Gênica , Técnicas de Inativação de Genes , Teste de Complementação Genética , Humanos , Ictiose/diagnóstico , Ictiose/metabolismo , Ictiose/patologia , Lactente , Recém-Nascido , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Ceratodermia Palmar e Plantar/diagnóstico , Ceratodermia Palmar e Plantar/metabolismo , Ceratodermia Palmar e Plantar/patologia , Linhagem , Permeabilidade , Sequenciamento Completo do Exoma , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismo
6.
BMC Med Genet ; 21(1): 59, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32209057

RESUMO

BACKGROUND: Intellectual disability (ID) is both a clinically diverse and genetically heterogeneous group of disorder, with an onset of cognitive impairment before the age of 18 years. ID is characterized by significant limitations in intellectual functioning and adaptive behaviour. The identification of genetic variants causing ID and neurodevelopmental disorders using whole-exome sequencing (WES) has proven to be successful. So far more than 1222 primary and 1127 candidate genes are associated with ID. METHODS: To determine pathogenic variants causative of ID in three unrelated consanguineous Pakistani families, we used a combination of WES, homozygosity-by-descent mapping, de-deoxy sequencing and bioinformatics analysis. RESULTS: Rare pathogenic single nucleotide variants identified by WES which passed our filtering strategy were confirmed by traditional Sanger sequencing and segregation analysis. Novel and deleterious variants in VPS53, GLB1, and MLC1, genes previously associated with variable neurodevelopmental anomalies, were found to segregate with the disease in the three families. CONCLUSIONS: This study expands our knowledge on the molecular basis of ID as well as the clinical heterogeneity associated to different rare genetic causes of neurodevelopmental disorders. This genetic study could also provide additional knowledge to help genetic assessment as well as clinical and social management of ID in Pakistani families.


Assuntos
Consanguinidade , Deficiência Intelectual/genética , Proteínas de Membrana/genética , Polimorfismo Genético , Proteínas de Transporte Vesicular/genética , beta-Galactosidase/genética , Criança , Pré-Escolar , Família , Feminino , Genes Recessivos/genética , Heterogeneidade Genética , Testes Genéticos , Homozigoto , Humanos , Deficiência Intelectual/complicações , Deficiência Intelectual/patologia , Masculino , Transtornos do Neurodesenvolvimento/complicações , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia , Paquistão/epidemiologia , Linhagem , Sequenciamento Completo do Exoma
7.
PLoS Genet ; 16(2): e1008590, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32053595

RESUMO

The 1.6 Mbp deletion on chromosome 3q29 is associated with a range of neurodevelopmental disorders, including schizophrenia, autism, microcephaly, and intellectual disability. Despite its importance towards neurodevelopment, the role of individual genes, genetic interactions, and disrupted biological mechanisms underlying the deletion have not been thoroughly characterized. Here, we used quantitative methods to assay Drosophila melanogaster and Xenopus laevis models with tissue-specific individual and pairwise knockdown of 14 homologs of genes within the 3q29 region. We identified developmental, cellular, and neuronal phenotypes for multiple homologs of 3q29 genes, potentially due to altered apoptosis and cell cycle mechanisms during development. Using the fly eye, we screened for 314 pairwise knockdowns of homologs of 3q29 genes and identified 44 interactions between pairs of homologs and 34 interactions with other neurodevelopmental genes. Interestingly, NCBP2 homologs in Drosophila (Cbp20) and X. laevis (ncbp2) enhanced the phenotypes of homologs of the other 3q29 genes, leading to significant increases in apoptosis that disrupted cellular organization and brain morphology. These cellular and neuronal defects were rescued with overexpression of the apoptosis inhibitors Diap1 and xiap in both models, suggesting that apoptosis is one of several potential biological mechanisms disrupted by the deletion. NCBP2 was also highly connected to other 3q29 genes in a human brain-specific interaction network, providing support for the relevance of our results towards the human deletion. Overall, our study suggests that NCBP2-mediated genetic interactions within the 3q29 region disrupt apoptosis and cell cycle mechanisms during development.


Assuntos
Encéfalo/embriologia , Cromossomos Humanos Par 3/genética , Proteínas de Drosophila/genética , Desenvolvimento Embrionário/genética , Deficiência Intelectual/genética , Complexo Proteico Nuclear de Ligação ao Cap/genética , Proteínas de Xenopus/genética , Animais , Apoptose/genética , Encéfalo/patologia , Ciclo Celular/genética , Deleção Cromossômica , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/patologia , Modelos Animais de Doenças , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Embrião não Mamífero , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Redes Reguladoras de Genes , Humanos , Deficiência Intelectual/patologia , Complexo Proteico Nuclear de Ligação ao Cap/metabolismo , Proteínas de Xenopus/metabolismo , Xenopus laevis
8.
BMC Med Genet ; 21(1): 31, 2020 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-32050918

RESUMO

BACKGROUND: Intellectual disability (ID) constitutes the most common group of neurodevelopmental disorders. Exome sequencing has enabled the discovery of genetic mutations responsible for a wide range of ID disorders. CASE PRESENTATION: In this study, we reported on two male siblings, aged 4 and 2 years, with motor and mental developmental delays and mild dysmorphic facial features. To identify the genetic causes of these symptoms, we employed trio-whole exome sequencing for the proband. We found a novel hemizygous missense variant in the PAK3 gene (c.1112G > A, p.Cys371Tyr), which encodes the p21-activated kinase 3, in the proband, which inherited from mother. The younger brother also has the hemizygous variant, which was confirmed by Sanger sequencing. The variant is located in the kinase domain and was regarded as a likely pathogenic variant in this family. CONCLUSION: We diagnosed two male siblings with developmental delays as having a PAK3 likely pathogenic variant. This finding expands the list of PAK3 gene mutations associated with neurodevelopmental disorders and provides further details on its clinical features.


Assuntos
Deficiências do Desenvolvimento/genética , Predisposição Genética para Doença , Deficiência Intelectual/genética , Quinases Ativadas por p21/genética , Adolescente , Criança , Deficiências do Desenvolvimento/patologia , Estudos de Associação Genética , Humanos , Deficiência Intelectual/patologia , Masculino , Mutação/genética , Mutação de Sentido Incorreto , Linhagem , Irmãos , Sequenciamento Completo do Exoma
10.
Clin Dysmorphol ; 29(1): 46-48, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31205051
11.
Clin Dysmorphol ; 29(1): 10-16, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31577543

RESUMO

With the increasing availability and clinical use of exome and whole-genome sequencing, reverse phenotyping is now becoming common practice in clinical genetics. Here, we report a patient identified through the Wellcome Trust Deciphering Developmental Disorders study who has homozygous pathogenic variants in CC2D2A and a de-novo heterozygous pathogenic variant in KIDINS220. He presents with developmental delay, intellectual disability, and oculomotor apraxia. Reverse phenotyping has demonstrated that he likely has a composite phenotype with contributions from both variants. The patient is much more mildly affected than those with Joubert Syndrome or Spastic paraplegia, intellectual disability, nystagmus, and obesity, the conditions associated with CC2D2A and KIDINS220 respectively, and therefore, contributes to the phenotypic variability associated with the two conditions.


Assuntos
Anormalidades Múltiplas , Cerebelo/anormalidades , Proteínas do Citoesqueleto/genética , Deficiências do Desenvolvimento , Anormalidades do Olho , Deficiência Intelectual , Doenças Renais Císticas , Proteínas de Membrana/genética , Mutação , Proteínas do Tecido Nervoso/genética , Retina/anormalidades , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Anormalidades Múltiplas/fisiopatologia , Cerebelo/patologia , Cerebelo/fisiopatologia , Criança , Pré-Escolar , Deficiências do Desenvolvimento/genética , Deficiências do Desenvolvimento/patologia , Deficiências do Desenvolvimento/fisiopatologia , Anormalidades do Olho/genética , Anormalidades do Olho/patologia , Anormalidades do Olho/fisiopatologia , Homozigoto , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Deficiência Intelectual/fisiopatologia , Doenças Renais Císticas/genética , Doenças Renais Císticas/patologia , Doenças Renais Císticas/fisiopatologia , Masculino , Retina/patologia , Retina/fisiopatologia
13.
BMC Med Genomics ; 12(1): 156, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694657

RESUMO

BACKGROUND: Non-syndromic intellectual disability is genetically heterogeneous with dominant, recessive and complex forms of inheritance. We have performed detailed genetic studies in a large multi-generational Swedish family, including several members diagnosed with non-syndromic intellectual disability. Linkage analysis was performed on 22 family members, nine affected with mild to moderate intellectual disability and 13 unaffected family members. METHODS: Family members were analyzed with Affymetrix Genome-Wide Human SNP Array 6.0 and the genetic data was used to detect copy number variation and to perform genome wide linkage analysis with the SNP High Throughput Linkage analysis system and the Merlin software. For the exome sequencing, the samples were prepared using the Sure Select Human All Exon Kit (Agilent Technologies, Santa Clara, CA, USA) and sequenced using the Ion Proton™ System. Validation of identified variants was performed with Sanger sequencing. RESULTS: The linkage analysis results indicate that intellectual disability in this family is genetically heterogeneous, with suggestive linkage found on chromosomes 1q31-q41, 4q32-q35, 6p25 and 14q24-q31 (LOD scores of 2.4, simulated p-value of 0.000003 and a simulated genome-wide p-value of 0.06). Exome sequencing was then performed in 14 family members and 7 unrelated individuals from the same region. The analysis of coding variation revealed a pathogenic and candidate variants in different branches of the family. In three patients we find a known homozygous pathogenic mutation in the Homo sapiens solute carrier family 17 member 5 (SLC17A5), causing Salla disease. We also identify a deletion overlapping KDM3B and a duplication overlapping MAP3K4 and AGPAT4, both overlapping variants previously reported in developmental disorders. CONCLUSIONS: DNA samples from the large family analyzed in this study were initially collected based on a hypothesis that affected members shared a major genetic risk factor. Our results show that a complex phenotype such as mild intellectual disability in large families from genetically isolated populations may show considerable genetic heterogeneity.


Assuntos
Exoma/genética , Ligação Genética , Deficiência Intelectual/genética , 1-Acilglicerol-3-Fosfato O-Aciltransferase/genética , Variações do Número de Cópias de DNA , Humanos , Deficiência Intelectual/patologia , Histona Desmetilases com o Domínio Jumonji/genética , Cariotipagem , MAP Quinase Quinase Quinase 4/genética , Transportadores de Ânions Orgânicos/genética , Linhagem , Polimorfismo de Nucleotídeo Único , Suécia , Simportadores/genética , Sequenciamento Completo do Exoma
14.
Hum Genomics ; 13(1): 53, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640787

RESUMO

BACKGROUND: Dysfunction in inwardly rectifying potassium channel Kir4.1 has been implicated in SeSAME syndrome, an autosomal-recessive (AR), rare, multi-systemic disorder. However, not all neurological, intellectual disability, and comorbid phenotypes in SeSAME syndrome can be mechanistically linked solely to Kir4.1 dysfunction. METHODS: We therefore performed whole-exome sequencing and identified additional genetic risk-elements that might exert causative effects either alone or in concert with Kir4.1 in a family diagnosed with SeSAME syndrome. RESULTS: Two variant prioritization pipelines based on AR inheritance and runs of homozygosity (ROH), identified two novel homozygous variants in KCNJ10 and PI4KB and five rare homozygous variants in PVRL4, RORC, FLG2, FCRL1, NIT1 and one common homozygous variant in HSPA6 segregating in all four patients. The novel mutation in KCNJ10 resides in the cytoplasmic domain of Kir4.1, a seat of phosphatidylinositol bisphosphate (PIP2) binding. The mutation altered the subcellular localization and stability of Kir4.1 in patient-specific lymphoblastoid cells (LCLs) compared to parental controls. Barium-sensitive endogenous K+ currents in patient-specific LCLs using whole-cell patch-clamp electrophysiology revealed membrane depolarization and defects in inward K+ ion conductance across the membrane, thereby suggesting a loss-of-function effect of KCNJ10 variant. CONCLUSION: Altogether, our findings implicate the role of new genes in SeSAME syndrome without electrolyte imbalance and thereby speculate the regulation of Kir4.1 channel activity by PIP2 and integrin-mediated adhesion signaling mechanisms.


Assuntos
Perda Auditiva Neurossensorial/genética , Deficiência Intelectual/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Canais de Potássio Corretores do Fluxo de Internalização/genética , Convulsões/genética , Adolescente , Adulto , Criança , Feminino , Perda Auditiva Neurossensorial/patologia , Homozigoto , Humanos , Deficiência Intelectual/patologia , Masculino , Mutação/genética , Fenótipo , Convulsões/patologia , Sequenciamento Completo do Exoma , Adulto Jovem
15.
J Pediatr Endocrinol Metab ; 32(11): 1287-1293, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31472064

RESUMO

Background Woodhouse-Sakati syndrome (WSS) (OMIM#241080) is an extremely rare multisystemic disease. Alopecia, hypogonadism, loss of hearing, hypothyroidism, diabetes mellitus (DM) and neurological disorders are the components of this syndrome. The syndrome is caused by homozygous or compound heterozygous mutations in DCAF17, and has recently been implicated in the development of both male and female gonads, thus resulting in hypogonadism. Case report A 16-year-old girl with consanguineous parents was admitted to our hospital with absence of breast development and amenorrhea. Hypogonadism was detected, in the form of hypergonadotropic hypogonadism. Whole-exome sequencing was used to identify the genetic etiology underlying the hypogonadism. A novel homozygous variant c.1091 + 1G > A was detected in DCAF17. Both parents were sequenced and identified as heterozygous for the same mutation. Conclusions We report a novel mutation detected in the DCAF17 gene and discuss the clinical findings in patients with previously reported mutations. Various manifestations of WSS, such as alopecia, endocrinological and neurological disorders, do not emerge until later in life, and therefore this situation can be challenging to diagnose particularly in pediatric cases, as in the present report. Careful attention should be paid to these additional findings, which may lead to early diagnosis and reduced genetic analysis costs, in patients with hypogonadism. In addition, there was no obvious genetic-phenotype correlation in reported cases.


Assuntos
Alopecia/genética , Alopecia/patologia , Arritmias Cardíacas/genética , Arritmias Cardíacas/patologia , Doenças dos Gânglios da Base/genética , Doenças dos Gânglios da Base/patologia , Diabetes Mellitus/genética , Diabetes Mellitus/patologia , Homozigoto , Hipogonadismo/patologia , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Mutação , Proteínas Nucleares/genética , Complexos Ubiquitina-Proteína Ligase/genética , Adolescente , Feminino , Humanos , Hipogonadismo/genética , Prognóstico
16.
Stem Cell Res ; 40: 101545, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31472451

RESUMO

Here we describe the generation and characterization of the human induced pluripotent stem cell (iPSC) lines from urine-derived cells (UCs) from two patients with unbalanced chromosomal translocation t(3,22)(q28;q13.3). The iPSC lines retain the original chromosome abnormality, express pluripotency markers and bear differentiation potential.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Translocação Genética , Diferenciação Celular , Linhagem Celular , Cromossomos Humanos Par 22 , Cromossomos Humanos Par 3 , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Cariótipo , Masculino
17.
J Mol Neurosci ; 69(4): 538-545, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31414351

RESUMO

Intellectual disability (ID) is characterized by limited mental ability and adaptive behavior that imposes a heavy burden on the patients' families and the health care system. This study was aimed at determining the molecular aspect of nonsyndromic ID, in a family from South Khorasan Province in Iran. Exome sequencing was performed, as well as complete clinical examinations of the family. Afterward, in silico studies have been done to examine the changes that occurred in the protein structure, in association with the ID phenotype. The PIGG (NC_000004.12) mutation was found on Chr 4:517639G>A, and this chromosomal location was proposed as the disorder-causing variant. This Arg658Gln alteration was confirmed by Sanger sequencing, using specific primers for PIGG. In conclusion, our study indicated a novel mutation in the PIGG in the affected family. This mutation is a novel variant (p. R658Q) with an autosomal recessive inheritance pattern. These findings could improve genetic counseling in the future.


Assuntos
Deficiência Intelectual/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Mutação Puntual , Sítios de Ligação , Feminino , Humanos , Deficiência Intelectual/patologia , Masculino , Linhagem , Fosfotransferases (Aceptor do Grupo Álcool)/química , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Ligação Proteica
19.
Mol Cell ; 75(5): 891-904.e7, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31375262

RESUMO

Mammalian SWI/SNF complexes are multi-subunit chromatin remodeling complexes associated with an ATPase (either SMARCA4 or SMARCA2). Heterozygous mutations in the SMARCA2 ATPase cause Nicolaides-Baraitser syndrome (NCBRS), an intellectual disability syndrome associated with delayed speech onset. We engineered human embryonic stem cells (hESCs) to carry NCBRS-associated heterozygous SMARCA2 K755R or R1159Q mutations. While SMARCA2 mutant hESCs were phenotypically normal, differentiation to neural progenitors cells (NPCs) was severely impaired. We find that SMARCA2 mutations cause enhancer reorganization with loss of SOX3-dependent neural enhancers and prominent emergence of astrocyte-specific de novo enhancers. Changes in chromatin accessibility at enhancers were associated with an increase in SMARCA2 binding and retargeting of SMARCA4. We show that the AP-1 family member FRA2 is aberrantly overexpressed in SMARCA2 mutant NPCs, where it functions as a pioneer factor at de novo enhancers. Together, our results demonstrate that SMARCA2 mutations cause impaired differentiation through enhancer reprogramming via inappropriate targeting of SMARCA4.


Assuntos
DNA Helicases/metabolismo , Elementos Facilitadores Genéticos , Heterozigoto , Células-Tronco Embrionárias Humanas/metabolismo , Mutação de Sentido Incorreto , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Substituição de Aminoácidos , Diferenciação Celular/genética , Cromatina/genética , Cromatina/metabolismo , DNA Helicases/genética , Facies , Deformidades Congênitas do Pé/genética , Deformidades Congênitas do Pé/metabolismo , Deformidades Congênitas do Pé/patologia , Antígeno 2 Relacionado a Fos/biossíntese , Antígeno 2 Relacionado a Fos/genética , Células HEK293 , Células-Tronco Embrionárias Humanas/patologia , Humanos , Hipotricose/genética , Hipotricose/metabolismo , Hipotricose/patologia , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Deficiência Intelectual/patologia , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologia , Proteínas Nucleares/genética , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Fatores de Transcrição/genética
20.
Am J Med Genet C Semin Med Genet ; 181(3): 345-353, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31410997

RESUMO

Arthrogryposis or AMC, arthrogryposis multiplex congenita, is defined as multiple congenital joint contractures in more than two joints and in different body areas. The common cause of all AMC is lack of movement in utero, which in turn can have different causes, one of which is CNS involvement. Intellectual disability/CNS involvement is found in approximately 25% of all AMC. AMC with CNS involvement includes a large number of genetic syndromes. So far, more than 400 genes have been identified as linked to AMC, with and without CNS involvement. A number of neonatally lethal syndromes and syndromes resulting in severe disability due to CNS malfunction belong to this group of syndromes. There are several X-linked disorders with AMC, which are primarily related to intellectual disability. A number of neuromuscular disorders may include AMC and CNS/brain involvement. Careful clinical evaluation by a geneticist and a pediatrician/pediatric neurologist is the first step in making a specific diagnosis. Further investigations may include MRI of the brain and spinal cord, electroencephalogram, blood chemistry for muscle enzymes, other organ investigations (ophtalmology, cardiology, gastrointestinal, and genitourinary systems). Nerve conduction studies, electromyogram, and muscle pathology may be of help when there is associated peripheral nervous system involvement. But most importantly, genetic investigations with targeted or rather whole exome or genome sequencing should be performed. A correct diagnosis is important in planning adequate treatment, in genetic counselling and also for future understanding of pathogenic mechanisms and possible new treatments. A multidiciplinary team is needed both in investigation and treatment.


Assuntos
Artrogripose/diagnóstico , Artrogripose/patologia , Encéfalo/patologia , Artrogripose/genética , Eletroencefalografia/métodos , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Imagem por Ressonância Magnética/métodos , Medula Espinal/patologia
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