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1.
J Child Neurol ; 33(10): 642-650, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29882456

RESUMO

Leukodystrophies and genetic leukoencephalopathies are a heterogeneous group of heritable disorders that affect the glial-axonal unit. As more patients with unsolved leukodystrophies and genetic leukoencephalopathies undergo next generation sequencing, causative mutations in genes leading to central hypomyelination are being identified. Two such individuals presented with arthrogryposis multiplex congenita, congenital hypomyelinating neuropathy, and central hypomyelination with early respiratory failure. Whole exome sequencing identified biallelic mutations in the CNTNAP1 gene: homozygous c.1163G>C (p.Arg388Pro) and compound heterozygous c.967T>C (p.Cys323Arg) and c.319C>T (p.Arg107*). Sural nerve and quadriceps muscle biopsies demonstrated progressive, severe onion bulb and axonal pathology. By ultrastructural evaluation, septate axoglial paranodal junctions were absent from nodes of Ranvier. Serial brain magnetic resonance images revealed hypomyelination, progressive atrophy, and reduced diffusion in the globus pallidus in both patients. These 2 families illustrate severe progressive peripheral demyelinating neuropathy due to the absence of septate paranodal junctions and central hypomyelination with neurodegeneration in CNTNAP1-associated arthrogryposis multiplex congenita.

2.
Am J Med Genet A ; 176(6): 1443-1448, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29696782

RESUMO

Early-onset epileptic encephalopathies (EOEEs) are a genetically heterogeneous collection of severe epilepsies often associated with psychomotor regression. Mutations in SZT2, a known seizure threshold regulator gene, are a newly identified cause of EOEE. We present an individual with EOEE, macrocephaly, and developmental regression with compound heterozygous mutations in SZT2 as identified by whole exome sequencing. Serial imaging characterized the novel finding of progressive loss of central myelination. This case expands our clinical understanding of the SZT2-phenotype and emphasizes the role of this gene in the diagnostic investigation for EOEE and leukoencephalopathies.

3.
Mol Genet Metab ; 122(1-2): 18-32, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28863857

RESUMO

Leukodystrophies are a broad class of genetic disorders that result in disruption or destruction of central myelination. Although the mechanisms underlying these disorders are heterogeneous, there are many common symptoms that affect patients irrespective of the genetic diagnosis. The comfort and quality of life of these children is a primary goal that can complement efforts directed at curative therapies. Contained within this report is a systems-based approach to management of complications that result from leukodystrophies. We discuss the initial evaluation, identification of common medical issues, and management options to establish a comprehensive, standardized care approach. We will also address clinical topics relevant to select leukodystrophies, such as gallbladder pathology and adrenal insufficiency. The recommendations within this review rely on existing studies and consensus opinions and underscore the need for future research on evidence-based outcomes to better treat the manifestations of this unique set of genetic disorders.


Assuntos
Doenças Desmielinizantes/terapia , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/terapia , Leucoencefalopatias/terapia , Doenças por Armazenamento dos Lisossomos/prevenção & controle , Doenças por Armazenamento dos Lisossomos/terapia , Insuficiência Adrenal/terapia , Adulto , Criança , Doenças Desmielinizantes/congênito , Feminino , Vesícula Biliar/patologia , Predisposição Genética para Doença , Humanos , Leucoencefalopatias/congênito , Masculino , Qualidade de Vida
4.
Pediatr Neurol ; 66: 59-62, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27843092

RESUMO

BACKGROUND: Leukoencephalopathy with temporal lobe cysts may be associated with monogenetic conditions such as Aicardi-Goutières syndrome or RNASET2 mutations and with congenital infections such as cytomegalovirus. In view of the fact that congenital cytomegalovirus is difficult to confirm outside the neonatal period, excluding a Mendelian disorder is extremely relevant, changing family planning and medical management in affected families. We performed diagnostic testing in individuals with leukoencephalopathy with temporal lobe cysts without a definitive diagnosis of congenital cytomegalovirus infection. METHODS: We reviewed a large-scale biorepository of patients with unsolved leukodystrophies and identified two individuals with required for meiotic nuclear division 1 (RMND1) mutations and similar magnetic resonance imaging (MRI) features, including temporal lobe cysts. Ten additional subjects with confirmed RMND1 mutations were identified as part of a separate disease specific cohort. Brain MRIs from all 12 individuals were reviewed for common neuroradiological features. RESULTS: MRI features in RMND1 mutations included temporal lobe swelling, with rarefaction and cystic evolution, enlarged tips of the temporal lobes, and multifocal subcortical white matter changes with confluent periatrial T2 signal hyperintensity. A combination of these features was present in ten of the 12 individuals reviewed. CONCLUSIONS: Despite the small number of reported individuals with RMND1 mutations, a clinically recognizable phenotype of leukoencephalopathy with temporal lobe swelling, rarefaction, and cystic changes has emerged in a subset of individuals. Careful clinical phenotyping, including for lactic acidosis, deafness, and severe muscle involvement seen in RMND1 mutation positive individuals, and MRI pattern recognition will be important in differentiating these patients from children with congenital infections like cytomegalovirus.


Assuntos
Neoplasias Encefálicas/genética , Proteínas de Ciclo Celular/genética , Infecções por Citomegalovirus/congênito , Surdez/genética , Leucoencefalopatias/genética , Neoplasias Encefálicas/diagnóstico por imagem , Criança , Pré-Escolar , Estudos de Coortes , Cistos/diagnóstico por imagem , Infecções por Citomegalovirus/diagnóstico por imagem , Infecções por Citomegalovirus/genética , Surdez/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Lactente , Leucoencefalopatias/diagnóstico por imagem , Mutação , Fenótipo , Lobo Temporal/diagnóstico por imagem
6.
Ann Neurol ; 79(6): 1031-1037, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27159321

RESUMO

Here we report whole exome sequencing (WES) on a cohort of 71 patients with persistently unresolved white matter abnormalities with a suspected diagnosis of leukodystrophy or genetic leukoencephalopathy. WES analyses were performed on trio, or greater, family groups. Diagnostic pathogenic variants were identified in 35% (25 of 71) of patients. Potentially pathogenic variants were identified in clinically relevant genes in a further 7% (5 of 71) of cases, giving a total yield of clinical diagnoses in 42% of individuals. These findings provide evidence that WES can substantially decrease the number of unresolved white matter cases. Ann Neurol 2016;79:1031-1037.


Assuntos
Análise Mutacional de DNA , Exoma/genética , Leucoencefalopatias/diagnóstico , Leucoencefalopatias/genética , Substância Branca/patologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Leucoencefalopatias/patologia , Masculino , Mutação , Adulto Jovem
7.
Am J Hum Genet ; 96(4): 675-81, 2015 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-25817015

RESUMO

Mutations in genes encoding aminoacyl-tRNA synthetases are known to cause leukodystrophies and genetic leukoencephalopathies-heritable disorders that result in white matter abnormalities in the central nervous system. Here we report three individuals (two siblings and an unrelated individual) with severe infantile epileptic encephalopathy, clubfoot, absent deep tendon reflexes, extrapyramidal symptoms, and persistently deficient myelination on MRI. Analysis by whole exome sequencing identified mutations in the nuclear-encoded alanyl-tRNA synthetase (AARS) in these two unrelated families: the two affected siblings are compound heterozygous for p.Lys81Thr and p.Arg751Gly AARS, and the single affected child is homozygous for p.Arg751Gly AARS. The two identified mutations were found to result in a significant reduction in function. Mutations in AARS were previously associated with an autosomal-dominant inherited form of axonal neuropathy, Charcot-Marie-Tooth disease type 2N (CMT2N). The autosomal-recessive AARS mutations identified in the individuals described here, however, cause a severe infantile epileptic encephalopathy with a central myelin defect and peripheral neuropathy, demonstrating that defects of alanyl-tRNA charging can result in a wide spectrum of disease manifestations.


Assuntos
Anormalidades Múltiplas/genética , Alanina-tRNA Ligase/genética , Epilepsia/genética , Modelos Moleculares , Bainha de Mielina/patologia , Doenças do Sistema Nervoso Periférico/genética , Fenótipo , Anormalidades Múltiplas/patologia , Alanina-tRNA Ligase/química , Sequência de Aminoácidos , Sequência de Bases , Epilepsia/patologia , Genes Recessivos/genética , Humanos , Lactente , Recém-Nascido , Dados de Sequência Molecular , Mutação/genética , Doenças do Sistema Nervoso Periférico/patologia , Estudos Prospectivos , Análise de Sequência de DNA , Síndrome , Estados Unidos
8.
Am J Med Genet A ; 167A(2): 296-312, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25604658

RESUMO

Aicardi-Goutières syndrome is an inflammatory disease occurring due to mutations in any of TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR or IFIH1. We report on 374 patients from 299 families with mutations in these seven genes. Most patients conformed to one of two fairly stereotyped clinical profiles; either exhibiting an in utero disease-onset (74 patients; 22.8% of all patients where data were available), or a post-natal presentation, usually within the first year of life (223 patients; 68.6%), characterized by a sub-acute encephalopathy and a loss of previously acquired skills. Other clinically distinct phenotypes were also observed; particularly, bilateral striatal necrosis (13 patients; 3.6%) and non-syndromic spastic paraparesis (12 patients; 3.4%). We recorded 69 deaths (19.3% of patients with follow-up data). Of 285 patients for whom data were available, 210 (73.7%) were profoundly disabled, with no useful motor, speech and intellectual function. Chilblains, glaucoma, hypothyroidism, cardiomyopathy, intracerebral vasculitis, peripheral neuropathy, bowel inflammation and systemic lupus erythematosus were seen frequently enough to be confirmed as real associations with the Aicardi-Goutieres syndrome phenotype. We observed a robust relationship between mutations in all seven genes with increased type I interferon activity in cerebrospinal fluid and serum, and the increased expression of interferon-stimulated gene transcripts in peripheral blood. We recorded a positive correlation between the level of cerebrospinal fluid interferon activity assayed within one year of disease presentation and the degree of subsequent disability. Interferon-stimulated gene transcripts remained high in most patients, indicating an ongoing disease process. On the basis of substantial morbidity and mortality, our data highlight the urgent need to define coherent treatment strategies for the phenotypes associated with mutations in the Aicardi-Goutières syndrome-related genes. Our findings also make it clear that a window of therapeutic opportunity exists relevant to the majority of affected patients and indicate that the assessment of type I interferon activity might serve as a useful biomarker in future clinical trials.


Assuntos
Adenosina Desaminase/genética , Doenças Autoimunes do Sistema Nervoso/diagnóstico , Doenças Autoimunes do Sistema Nervoso/genética , RNA Helicases DEAD-box/genética , Exodesoxirribonucleases/genética , Proteínas Monoméricas de Ligação ao GTP/genética , Mutação , Malformações do Sistema Nervoso/diagnóstico , Malformações do Sistema Nervoso/genética , Fenótipo , Fosfoproteínas/genética , Ribonuclease H/genética , Estudos de Associação Genética , Genótipo , Humanos , Helicase IFIH1 Induzida por Interferon , Interferons/sangue , Interferons/líquido cefalorraquidiano , Pterinas/líquido cefalorraquidiano , Proteína 1 com Domínio SAM e Domínio HD
9.
J Genet Couns ; 23(5): 734-41, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24777551

RESUMO

Uniparental disomy is a genetic cause of disease that may result in the inheritance of an autosomal recessive condition. A child with developmental delay and hypotonia was seen and found to have severely abnormal myelination. Lysosomal enzyme testing identified an isolated deficiency of beta-galactosidase. Subsequently, homozygous missense mutations in the galactosidase, beta 1 (GLB1) gene on chromosome 3 were found. Parental testing confirmed inheritance of two copies of the same mutated maternal GLB1 gene, and no paternal copy. SNP analysis was also done to confirm paternity. The patient was ultimately diagnosed with autosomal recessive GM1 gangliosidosis caused by maternal uniparental isodisomy. We provide a review of this patient and others in which uniparental disomy (UPD) of a non-imprinted chromosome unexpectedly caused an autosomal recessive condition. This is the first case of GM1 gangliosidosis reported in the literature to have been caused by UPD. It is important for genetic counselors and other health care providers to be aware of the possibility of autosomal recessive disease caused by UPD. UPD as a cause of autosomal recessive disease drastically changes the recurrence risk for families, and discussions surrounding UPD can be complex. Working with families to understand UPD when it occurs requires a secure and trusting counselor-family relationship.


Assuntos
Gangliosidose GM1/genética , Dissomia Uniparental , Feminino , Humanos , Lactente , Polimorfismo de Nucleotídeo Único
10.
Mol Genet Metab ; 111(3): 393-398, 2014 03.
Artigo em Inglês | MEDLINE | ID: mdl-24374284

RESUMO

OBJECTIVE: Pelizaeus-Merzbacher-like disease is a rare hypomyelinating leukodystrophy caused by autosomal recessive mutations in GJC2, encoding a gap junction protein essential for production of a mature myelin sheath. A previously identified GJC2 mutation (c.-167A>G) in the promoter region is hypothesized to disrupt a putative SOX10 binding site; however, the lack of additional mutations in this region and contradictory functional data have limited the interpretation of this variant. METHODS: We describe two independent Pelizaeus-Merzbacher-like disease families with a novel promoter region mutation and updated in vitro functional assays. RESULTS: A novel GJC2 mutation (c.-170A>G) in the promoter region was identified in Pelizaeus-Merzbacher-like disease patients. In vitro functional assays using human GJC2 promoter constructs demonstrated that this mutation and the previously described c.-167A>G mutation similarly diminished the transcriptional activity driven by SOX10 and the binding affinity for SOX10. INTERPRETATION: These findings support the role of GJC2 promoter mutations in Pelizaeus-Merzbacher-like disease. GJC2 promoter region mutation screening should be included in the evaluation of patients with unexplained hypomyelinating leukodystrophies.


Assuntos
Conexinas/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Regiões Promotoras Genéticas , Fatores de Transcrição SOXE/metabolismo , Adulto , Sítios de Ligação , Criança , Conexinas/metabolismo , Feminino , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/metabolismo , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Humanos , Masculino , Dados de Sequência Molecular , Mutação , Bainha de Mielina/patologia , Ligação Proteica , Fatores de Transcrição SOXE/genética
11.
Pediatr Neurol ; 50(1): 112-4, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24120652

RESUMO

BACKGROUND: More than half of patients with genetic leukoencephalopathies remain without a specific diagnosis; this is particularly true in individuals with a likely primary neuronal etiology, such as those in which abnormal white matter occurs in combination with severe epilepsy. PATIENT: A child with a severe early infantile epileptic encephalopathy and abnormal myelination underwent whole exome sequencing. RESULTS: Whole exome sequencing identified a heterozygous de novo mutation in KCNT1, a sodium-gated potassium channel gene. CONCLUSIONS: Severely delayed myelination was anecdotally reported in previous patients with KCNT1 mutations. This case reinforces that KCNT1 sequencing should be included in an investigation of patients with severely delayed myelination and epilepsy.


Assuntos
Epilepsia/complicações , Epilepsia/genética , Leucoencefalopatias/complicações , Leucoencefalopatias/genética , Mutação/genética , Proteínas do Tecido Nervoso/genética , Canais de Potássio/genética , Criança , Eletroencefalografia , Humanos , Imagem por Ressonância Magnética , Masculino , Modelos Moleculares
12.
Neurology ; 80(11): 997-1002, 2013 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-23408864

RESUMO

OBJECTIVE: This study explores a large panel of cytokines in plasma and CSF of patients with Aicardi-Goutières syndrome (AGS) at different ages, in order to establish signatures of cytokines most predictive of AGS. METHODS: Plasma from 22 subjects with known mutations were assayed for cytokines using the Milliplex MAP Immunobead system, and compared to results from 8 age-matched normal controls. CSF of 11 additional patients with mutation-proven AGS was tested in an identical manner and compared to results from age-matched controls. Samples were banked and analysis was carried out retrospectively. RESULTS: Significant elevations were seen in FMS-related tyrosine kinase 3 ligand, IP-10, interleukin (IL)-12p40, IL-15, tumor necrosis factor α, and soluble IL 2 receptor α in both AGS patient plasma and CSF relative to controls. Additionally, this cytokine signature was able to correctly cluster 9 of 11 AGS cases based on CSF values. While most cytokines decreased exponentially with age, a subgroup including IP-10 demonstrated persistent elevation beyond early childhood. CONCLUSION: Patients with AGS exhibit plasma and CSF elevations of proinflammatory cytokines. Selected cytokines remain persistently elevated beyond the initial disease phase. This panel of proinflammatory cytokines may be considered for use as diagnostic and therapeutic markers of disease, and may permit improved understanding of disease pathogenesis.


Assuntos
Doenças Autoimunes do Sistema Nervoso/patologia , Citocinas/biossíntese , Mediadores da Inflamação/metabolismo , Malformações do Sistema Nervoso/patologia , Adolescente , Doenças Autoimunes do Sistema Nervoso/sangue , Doenças Autoimunes do Sistema Nervoso/líquido cefalorraquidiano , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Criança , Pré-Escolar , Citocinas/sangue , Citocinas/líquido cefalorraquidiano , Feminino , Humanos , Lactente , Mediadores da Inflamação/sangue , Mediadores da Inflamação/líquido cefalorraquidiano , Masculino , Malformações do Sistema Nervoso/sangue , Malformações do Sistema Nervoso/líquido cefalorraquidiano , Estudos Retrospectivos
13.
Hum Pathol ; 38(11): 1714-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17954208

RESUMO

Congenital disorders of glycosylation are a recently recognized group of inherited, multisystem disorders caused by aberrant biosynthesis of glycoproteins. We report the clinical and postmortem findings in a 3-year-old boy with a history of multiple medical issues including developmental delay, epilepsy, chronic protein-losing enteropathy, respiratory failure, nephropathy, coagulopathy, and cardiomyopathy. As part of the workup, isoelectric focusing for congenital disorders of glycosylation showed carbohydrate-deficient transferrin with the mono-oligo/dioligo ratio of 0.700 (normal, 0.075-0.109), indicating an increased level of abnormally glycosylated transferrin. After supportive care, he died secondary to multisystem complications of his disease. General autopsy findings were notable for micronodular liver cirrhosis with iron overload, myocardial ischemia and calcification, and hypertrophied glomeruli. Examination of the brain revealed cerebral and cerebellar atrophy, diffuse astrogliosis, and meningeal fibrosis. This article reveals complete autopsy findings of untyped congenital disorders of glycosylation, congenital disorders of glycosylation-x, with an undefined metabolic basis.


Assuntos
Defeitos Congênitos da Glicosilação/patologia , Autopsia , Encéfalo/patologia , Pré-Escolar , Evolução Fatal , Humanos , Cirrose Hepática/patologia , Masculino , Transferrina/metabolismo
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