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1.
Clin Genet ; 2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33619735

RESUMO

Up to 40% of neurodevelopmental disorders (NDDs) such as intellectual disability, developmental delay, autism spectrum disorder, and developmental motor abnormalities have a documented underlying monogenic defect, primarily due to de novo variants. Still, the overall burden of de novo variants as well as novel disease genes in NDDs await discovery. We performed parent-offspring trio exome sequencing in 231 individuals with NDDs. Phenotypes were compiled using HPO terms. The overall diagnostic yield was 49.8% (n=115/231) with de novo variants contributing to more than 80% (n=93/115) of all solved cases. De novo variants affected 72 different - mostly constrained - genes. In addition, we identified putative pathogenic variants in 16 genes not linked to NDDs to date. Reanalysis performed in 80 initially unsolved cases revealed a definitive diagnosis in two additional cases. Our study consolidates the contribution and genetic heterogeneity of de novo variants in NDDs highlighting trio exome sequencing as effective diagnostic tool for NDDs. Besides, we illustrate the potential of a trio-approach for candidate gene discovery and the power of systematic reanalysis of unsolved cases.

3.
Brain ; 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33459760

RESUMO

The von Willebrand Factor A domain containing 1 protein, encoded by VWA1, is an extracellular matrix protein expressed in muscle and peripheral nerve. It interacts with collagen VI and perlecan, two proteins that are affected in hereditary neuromuscular disorders. Lack of VWA1 is known to compromise peripheral nerves in a Vwa1 knock-out mouse model. Exome sequencing led us to identify bi-allelic loss of function variants in VWA1 as the molecular cause underlying a so far genetically undefined neuromuscular disorder. We detected six different truncating variants in 15 affected individuals from six families of German, Arabic, and Roma descent. Disease manifested in childhood or adulthood with proximal and distal muscle weakness predominantly of the lower limbs. Myopathological and neurophysiological findings were indicative of combined neurogenic and myopathic pathology. Early childhood foot deformity was frequent, but no sensory signs were observed. Our findings establish VWA1 as a new disease gene confidently implicated in this autosomal recessive neuromyopathic condition presenting with child-/adult-onset muscle weakness as a key clinical feature.

4.
Brain ; 2020 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-33313762

RESUMO

Claudin-11, a tight junction protein, is indispensable in the formation of the radial component of myelin. Here, we report de novo stop-loss variants in the gene encoding claudin-11, CLDN11, in three unrelated individuals presenting with an early-onset spastic movement disorder, expressive speech disorder and eye abnormalities including hypermetropia. Brain MRI showed a myelin deficit with a discrepancy between T1-weighted and T2-weighted images and some progress in myelination especially involving the central and peripheral white matter. Exome sequencing identified heterozygous stop-loss variants c.622T>C, p.(*208Glnext*39) in two individuals and c.622T>G, p.(*208Gluext*39) in one individual, all occurring de novo. At the RNA level, the variant c.622T>C did not lead to a loss of expression in fibroblasts, indicating this transcript is not subject to nonsense-mediated decay and most likely translated into an extended protein. Extended claudin-11 is predicted to form an alpha helix not incorporated into the cytoplasmic membrane, possibly perturbing its interaction with intracellular proteins. Our observations suggest that stop-loss variants in CLDN11 expand the genetically heterogeneous spectrum of hypomyelinating leukodystrophies.

5.
Genet Med ; 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33149277

RESUMO

PURPOSE: A few de novo missense variants in the cytoplasmic FMRP-interacting protein 2 (CYFIP2) gene have recently been described as a novel cause of severe intellectual disability, seizures, and hypotonia in 18 individuals, with p.Arg87 substitutions in the majority. METHODS: We assembled data from 19 newly identified and all 18 previously published individuals with CYFIP2 variants. By structural modeling and investigation of WAVE-regulatory complex (WRC)-mediated actin polymerization in six patient fibroblast lines we assessed the impact of CYFIP2 variants on the WRC. RESULTS: Sixteen of 19 individuals harbor two previously described and 11 novel (likely) disease-associated missense variants. We report p.Asp724 as second mutational hotspot (4/19 cases). Genotype-phenotype correlation confirms a consistently severe phenotype in p.Arg87 patients but a more variable phenotype in p.Asp724 and other substitutions. Three individuals with milder phenotypes carry putative loss-of-function variants, which remain of unclear pathogenicity. Structural modeling predicted missense variants to disturb interactions within the WRC or impair CYFIP2 stability. Consistent with its role in WRC-mediated actin polymerization we substantiate aberrant regulation of the actin cytoskeleton in patient fibroblasts. CONCLUSION: Our study expands the clinical and molecular spectrum of CYFIP2-related neurodevelopmental disorder and provides evidence for aberrant WRC-mediated actin dynamics as contributing cellular pathomechanism.

6.
Eur J Hum Genet ; 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887937

RESUMO

In about 30% of infantile, juvenile, or adolescent patients with steroid-resistant nephrotic syndrome (SRNS), a monogenic cause can be identified. The histological finding in SRNS is often focal segmental glomerulosclerosis (FSGS). Genetic data on adult patients are scarce with low diagnostic yields. Exome sequencing (ES) was performed in patients with adult disease onset and a high likelihood for hereditary FSGS. A high likelihood was defined if at least one of the following criteria was present: absence of a secondary cause, ≤25 years of age at initial manifestation, kidney biopsy with suspicion of a hereditary cause, extrarenal manifestations, and/or positive familial history/reported consanguinity. Patients were excluded if age at disease onset was <18 years. In 7/24 index patients with adult disease onset, a disease-causing variant could be identified by ES leading to a diagnostic yield of 29%. Eight different variants were identified in six known genes associated with monogenic kidney diseases. Six of these variants had been described before as disease-causing. In patients with a disease-causing variant, the median age at disease onset and end-stage renal disease was 26 and 38 years, respectively. The overall median time to a definite genetic diagnosis was 9 years. In 29% of patients with adult disease onset and suspected hereditary FSGS, a monogenic cause could be identified. The long delay up to the definite genetic diagnosis highlights the importance of obtaining an early genetic diagnosis to allow for personalized treatment options including weaning of immunosuppressive treatment, avoidance of repeated renal biopsy, and provision of accurate genetic counseling.

7.
Neurol Genet ; 6(5): e500, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32802957

RESUMO

Objective: Clinical, neuroimaging, and genetic characterization of 3 patients with LINS1-associated developmental regression, intellectual disability, dysmorphism, and further neurologic deficits. Methods: Three affected brothers from a consanguineous family from Afghanistan, their 2 healthy siblings, and both parents were all assessed in the clinic. General and neurologic examination, expert dysmorphology examination, and 3T brain MRI were performed. Whole-exome sequencing was performed for the 3 affected brothers, followed by Sanger sequencing in all available family members. Results: The index patient and his 2 affected brothers presented a complex neurologic syndrome with similar features but marked intrafamilial phenotypical variability, including varying degrees of cognitive impairment, speech impairment, dystonia, abnormal eye movements, and dysmorphic features. All 3 affected brothers are homozygous for a novel, pathogenic frameshift mutation in LINS1, c.1672_1679del, and p.Gly558Profs*22, whereas both parents and healthy siblings are heterozygous for the mutation. No major brain malformations were evident in 3T brain MRI of the affected brothers. Conclusion: This consanguineous family with a novel mutation expands the spectrum of LINS1-associated disorder to include developmental regression, oculomotor signs, and dystonia, previously not described in the published 9 cases of this rare disorder. The 3T-MRI data from our 3 patients and review of the neuroimaging data in the literature showed unspecific brain MRI changes. LINS1 protein is a known modulating factor of the Wnt signaling pathway, with important roles in organogenesis including of the cerebral cortex. More research is warranted to disentangle the underlying pathophysiologic mechanisms, leading to cognitive impairment and the complex phenotype of LINS1-associated disorder.

8.
Parkinsonism Relat Disord ; 77: 70-75, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32629324

RESUMO

INTRODUCTION: The gene encoding myelin-associated glycoprotein (MAG) has been implicated in autosomal-recessive spastic paraplegia type 75. To date, only four families with biallelic missense variants in MAG have been reported. The genotypic and phenotypic spectrum of MAG-associated disease awaits further elucidation. METHODS: Four unrelated patients with complex neurologic conditions underwent whole-exome sequencing within research or diagnostic settings. Following determination of the underlying genetic defects, in-depth phenotyping and literature review were performed. RESULTS: In all case subjects, we detected ultra-rare homozygous or compound heterozygous variants in MAG. The observed nonsense (c.693C > A [p.Tyr231*], c.980G > A [p.Trp327*], c.1126C > T [p.Gln376*], and 1522C > T [p.Arg508*]) and frameshift (c.517_521dupAGCTG [p.Trp174*]) alleles were predicted to result in premature termination of protein translation. Affected patients presented with variable combinations of psychomotor delay, ataxia, eye movement abnormalities, spasticity, dystonia, and neuropathic symptoms. Cerebellar signs, nystagmus, and pyramidal tract dysfunction emerged as unifying features in the majority of MAG-mutated individuals identified to date. CONCLUSIONS: Our study is the first to describe biallelic null variants in MAG, confirming that loss of myelin-associated glycoprotein causes severe infancy-onset disease with central and peripheral nervous system involvement.

9.
Genet Med ; 22(11): 1863-1873, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32699352

RESUMO

PURPOSE: Biallelic variants in LARS1, coding for the cytosolic leucyl-tRNA synthetase, cause infantile liver failure syndrome 1 (ILFS1). Since its description in 2012, there has been no systematic analysis of the clinical spectrum and genetic findings. METHODS: Individuals with biallelic variants in LARS1 were included through an international, multicenter collaboration including novel and previously published patients. Clinical variables were analyzed and functional studies were performed in patient-derived fibroblasts. RESULTS: Twenty-five individuals from 15 families were ascertained including 12 novel patients with eight previously unreported variants. The most prominent clinical findings are recurrent elevation of liver transaminases up to liver failure and encephalopathic episodes, both triggered by febrile illness. Magnetic resonance image (MRI) changes during an encephalopathic episode can be consistent with metabolic stroke. Furthermore, growth retardation, microcytic anemia, neurodevelopmental delay, muscular hypotonia, and infection-related seizures are prevalent. Aminoacylation activity is significantly decreased in all patient cells studied upon temperature elevation in vitro. CONCLUSION: ILFS1 is characterized by recurrent elevation of liver transaminases up to liver failure in conjunction with abnormalities of growth, blood, nervous system, and musculature. Encephalopathic episodes with seizures can occur independently from liver crises and may present with metabolic stroke.

10.
Neurol Genet ; 6(3): e425, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32582862

RESUMO

Objective: To expand the phenotypic spectrum of severity of POLR3-related leukodystrophy and identify genotype-phenotype correlations through study of patients with extremely severe phenotypes. Methods: We performed an international cross-sectional study on patients with genetically proven POLR3-related leukodystrophy and atypical phenotypes to identify 6 children, 3 males and 3 females, with an extremely severe phenotype compared with that typically reported. Clinical, radiologic, and molecular features were evaluated for all patients, and functional and neuropathologic studies were performed on 1 patient. Results: Each patient presented between 1 and 3 months of age with failure to thrive, severe dysphagia, and developmental delay. Four of the 6 children died before age 3 years. MRI of all patients revealed a novel pattern with atypical characteristics, including progressive basal ganglia and thalami abnormalities. Neuropathologic studies revealed patchy areas of decreased myelin in the cerebral hemispheres, cerebellum, brainstem, and spinal cord, with astrocytic gliosis in the white matter and microglial activation. Cellular vacuolization was observed in the thalamus and basal ganglia, and neuronal loss was evident in the putamen and caudate. Genotypic similarities were also present between all 6 patients, with one allele containing a POLR3A variant causing a premature stop codon and the other containing a specific intronic splicing variant (c.1771-7C>G), which produces 2 aberrant transcripts along with some wild-type transcript. Conclusions: We describe genotype-phenotype correlations at the extreme end of severity of the POLR3-related leukodystrophy spectrum and shed light on the complex disease pathophysiology.

11.
Am J Hum Genet ; 106(2): 246-255, 2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32004447

RESUMO

Ral (Ras-like) GTPases play an important role in the control of cell migration and have been implicated in Ras-mediated tumorigenicity. Recently, variants in RALA were also described as a cause of intellectual disability and developmental delay, indicating the relevance of this pathway to neuropediatric diseases. Here, we report the identification of bi-allelic variants in RALGAPA1 (encoding Ral GTPase activating protein catalytic alpha subunit 1) in four unrelated individuals with profound neurodevelopmental disability, muscular hypotonia, feeding abnormalities, recurrent fever episodes, and infantile spasms . Dysplasia of corpus callosum with focal thinning of the posterior part and characteristic facial features appeared to be unifying findings. RalGAPA1 was absent in the fibroblasts derived from two affected individuals suggesting a loss-of-function effect of the RALGAPA1 variants. Consequently, RalA activity was increased in these cell lines, which is in keeping with the idea that RalGAPA1 deficiency causes a constitutive activation of RalA. Additionally, levels of RalGAPB, a scaffolding subunit of the RalGAP complex, were dramatically reduced, indicating a dysfunctional RalGAP complex. Moreover, RalGAPA1 deficiency clearly increased cell-surface levels of lipid raft components in detached fibroblasts, which might indicate that anchorage-dependence of cell growth signaling is disturbed. Our findings indicate that the dysregulation of the RalA pathway has an important impact on neuronal function and brain development. In light of the partially overlapping phenotype between RALA- and RALGAPA1-associated diseases, it appears likely that dysregulation of the RalA signaling pathway leads to a distinct group of genetic syndromes that we suggest could be named RALopathies.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos/etiologia , Proteínas Ativadoras de GTPase/genética , Hipotonia Muscular/etiologia , Mutação , Proteínas do Tecido Nervoso/genética , Transtornos do Neurodesenvolvimento/etiologia , Espasmos Infantis/etiologia , Alelos , Movimento Celular , Proliferação de Células , Pré-Escolar , Família , Transtornos da Alimentação e da Ingestão de Alimentos/patologia , Feminino , Humanos , Lactente , Masculino , Hipotonia Muscular/patologia , Transtornos do Neurodesenvolvimento/patologia , Fenótipo , Espasmos Infantis/patologia
12.
Ann Clin Transl Neurol ; 6(7): 1319-1326, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31353862

RESUMO

A recurrent de novo missense variant in KCNC1, encoding a voltage-gated potassium channel expressed in inhibitory neurons, causes progressive myoclonus epilepsy and ataxia, and a nonsense variant is associated with intellectual disability. We identified three new de novo missense variants in KCNC1 in five unrelated individuals causing different phenotypes featuring either isolated nonprogressive myoclonus (p.Cys208Tyr), intellectual disability (p.Thr399Met), or epilepsy with myoclonic, absence and generalized tonic-clonic seizures, ataxia, and developmental delay (p.Ala421Val, three patients). Functional analyses demonstrated no measurable currents for all identified variants and dominant-negative effects for p.Thr399Met and p.Ala421Val predicting neuronal disinhibition as the underlying disease mechanism.


Assuntos
Estudos de Associação Genética , Mutação de Sentido Incorreto , Canais de Potássio Shaw/genética , Animais , Ataxia/genética , Criança , Códon sem Sentido , Humanos , Deficiência Intelectual/genética , Masculino , Epilepsias Mioclônicas Progressivas , Convulsões/genética , Canais de Potássio Shaw/fisiologia , Xenopus laevis
13.
Dtsch Arztebl Int ; 116(12): 197-204, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-31056085

RESUMO

BACKGROUND: In developed countries, global developmental disorders are encounter- ed in approximately 1% of all children. The causes are manifold, and no exogenous cause can be identified in about half of the affected children. The parallel investi- gation of the coding sequences of all genes of the affected individual (whole exome sequencing, WES) has developed into a successful diagnostic method for identify- ing the cause of the problem. It is not yet clear, however, when WES should best be used in routine clinical practice in order to exploit the potential of this method to the fullest. METHODS: In an interdisciplinary study, we carried out standardized clinical pheno- typing and a systematic genetic analysis (WES of the index patient and his or her parents, so-called trio WES) in 50 children with developmental disturbances of unclear etiology and with nonspecific neurological manifestations. RESULTS: In 21 children (42% of the collective), we were able to identify the cause of the disorder by demonstrating a mutation in a gene known to be associated with disease. Three of these children subsequently underwent specific treatment. In 22 other children (44%), we detected possibly etiological changes in candidate genes not currently known to be associated with human disease. CONCLUSION: Our detection rate of at least 42% is high in comparison with the results obtained in other studies from Germany and other countries to date and implies that WES can be used to good effect as a differential diagnostic tool in pediatric neurol- ogy. WES should be carried out in both the index patient and his or her parents (trio- WES) and accompanied by close interdisciplinary collaboration of human geneti- cists and pediatricians, by comprehensive and targeted phenotyping (also after the diagnosis is established), and by the meticulous evaluation of all gene variants.


Assuntos
Sequenciamento Completo do Exoma , Criança , Alemanha , Humanos
14.
Clin Genet ; 96(2): 134-139, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30945277

RESUMO

Pre-axial polydactyly (PPD) is characterized by well-developed non-functional 1st digit (thumb) duplication in hands and/or feet. It is mostly inherited in autosomal dominant manner. In the present study, two families of Pakistani origin, demonstrating unilateral PPD type A, have been characterized at clinical and genetic levels. Whole-exome sequencing (WES) revealed a nonsense mutation (c.84C > A, p.Tyr28*) in the STKLD1, located on chromosome 9q34.2, in affected individuals of both the families. Our findings report the first direct involvement of the STKLD1 in the digit development and highlight the importance of inclusion of this gene for screening individuals presenting non-syndromic recessive PPD.


Assuntos
Alelos , Códon sem Sentido , Polidactilia/diagnóstico , Polidactilia/genética , Sequenciamento Completo do Exoma , Mapeamento Cromossômico , Biologia Computacional/métodos , Consanguinidade , Genótipo , Humanos , Repetições de Microssatélites , Linhagem , Radiografia , Análise de Sequência de DNA
15.
JIMD Rep ; 44: 1-7, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29923093

RESUMO

SLC25A42 is an inner mitochondrial membrane protein which has been shown to transport coenzyme A through a lipid bilayer in vitro. A homozygous missense variant in this gene has been recently reported in 13 subjects of Arab descent presenting with mitochondriopathy with variable clinical manifestations. By exome sequencing, we identified two additional individuals carrying rare variants in this gene. One subject was found to carry the previously reported missense variant in homozygous state, while the second subject carried a homozygous canonical splice site variant resulting in a splice defect. With the identification of two additional cases, we corroborate the association between rare variants in SLC25A42 and a clinical presentation characterized by myopathy, developmental delay, lactic acidosis, and encephalopathy. Furthermore, we highlight the biochemical consequences of the splice defect by measuring a mild decrease of coenzyme A content in SLC25A42-mutant fibroblasts.

16.
Am J Hum Genet ; 103(5): 817-825, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30401461

RESUMO

ADP-ribosylation is a reversible posttranslational modification used to regulate protein function. ADP-ribosyltransferases transfer ADP-ribose from NAD+ to the target protein, and ADP-ribosylhydrolases, such as ADPRHL2, reverse the reaction. We used exome sequencing to identify five different bi-allelic pathogenic ADPRHL2 variants in 12 individuals from 8 families affected by a neurodegenerative disorder manifesting in childhood or adolescence with key clinical features including developmental delay or regression, seizures, ataxia, and axonal (sensori-)motor neuropathy. ADPRHL2 was virtually absent in available affected individuals' fibroblasts, and cell viability was reduced upon hydrogen peroxide exposure, although it was rescued by expression of wild-type ADPRHL2 mRNA as well as treatment with a PARP1 inhibitor. Our findings suggest impaired protein ribosylation as another pathway that, if disturbed, causes neurodegenerative diseases.


Assuntos
Ataxia Cerebelar/genética , Deficiências do Desenvolvimento/genética , Glicosídeo Hidrolases/genética , Mutação/genética , Doenças Neurodegenerativas/genética , ADP-Ribosilação/genética , Adenosina Difosfato Ribose/genética , Adolescente , Alelos , Criança , Pré-Escolar , Exoma/genética , Feminino , Humanos , Lactente , Masculino , Malformações do Sistema Nervoso/genética , Processamento de Proteína Pós-Traducional/genética
17.
Neuropediatrics ; 49(5): 330-338, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29940663

RESUMO

BACKGROUND: Primary microcephaly and profound global developmental delay have been considered the core clinical phenotype in patients with bi-allelic PRUNE1 mutations. METHODS: Linkage analysis and whole-exome sequencing (WES) in a multiplex family and extraction of further cases from a WES repository containing 571 children with severe developmental disabilities and neurologic symptoms. RESULTS: We identified bi-allelic PRUNE1 mutations in twelve children from six unrelated families. All patients who survived beyond the first 6 months of life had early-onset global developmental delay, bilateral spastic paresis, dysphagia and difficult-to-treat seizures, while congenital or later-evolving microcephaly was not a consistent finding. Brain MRI showed variable anomalies with progressive cerebral and cerebellar atrophies and T2-hyperintense brain stem lesions. Peripheral neuropathy was documented in five cases. Disease course was progressive in all patients and eight children died in the first or early second decade of life. In addition to the previously reported missense mutation p.(Asp106Asn), we observed a novel homozygous missense variant p.(Leu172Pro) and a homozygous contiguous gene deletion encompassing most of the PRUNE1 gene and part of the neighboring BNIPL gene. CONCLUSIONS: PRUNE1 deficiency causes severe early-onset disease affecting the central and peripheral nervous systems. Microcephaly is probably not a universal feature.


Assuntos
Encéfalo/patologia , Deficiências do Desenvolvimento , Progressão da Doença , Epilepsia Resistente a Medicamentos , Erros Inatos do Metabolismo , Microcefalia , Espasticidade Muscular , Paresia , Monoéster Fosfórico Hidrolases , Criança , Pré-Escolar , Deficiências do Desenvolvimento/etiologia , Deficiências do Desenvolvimento/genética , Epilepsia Resistente a Medicamentos/etiologia , Epilepsia Resistente a Medicamentos/genética , Feminino , Ligação Genética , Humanos , Erros Inatos do Metabolismo/complicações , Erros Inatos do Metabolismo/genética , Erros Inatos do Metabolismo/patologia , Erros Inatos do Metabolismo/fisiopatologia , Microcefalia/etiologia , Microcefalia/genética , Espasticidade Muscular/etiologia , Espasticidade Muscular/genética , Mutação de Sentido Incorreto , Paresia/etiologia , Paresia/genética , Linhagem , Monoéster Fosfórico Hidrolases/deficiência , Monoéster Fosfórico Hidrolases/genética , Sequenciamento Completo do Exoma
18.
Am J Hum Genet ; 102(6): 1018-1030, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29754768

RESUMO

Coenzyme A (CoA) is an essential metabolic cofactor used by around 4% of cellular enzymes. Its role is to carry and transfer acetyl and acyl groups to other molecules. Cells can synthesize CoA de novo from vitamin B5 (pantothenate) through five consecutive enzymatic steps. Phosphopantothenoylcysteine synthetase (PPCS) catalyzes the second step of the pathway during which phosphopantothenate reacts with ATP and cysteine to form phosphopantothenoylcysteine. Inborn errors of CoA biosynthesis have been implicated in neurodegeneration with brain iron accumulation (NBIA), a group of rare neurological disorders characterized by accumulation of iron in the basal ganglia and progressive neurodegeneration. Exome sequencing in five individuals from two unrelated families presenting with dilated cardiomyopathy revealed biallelic mutations in PPCS, linking CoA synthesis with a cardiac phenotype. Studies in yeast and fruit flies confirmed the pathogenicity of identified mutations. Biochemical analysis revealed a decrease in CoA levels in fibroblasts of all affected individuals. CoA biosynthesis can occur with pantethine as a source independent from PPCS, suggesting pantethine as targeted treatment for the affected individuals still alive.


Assuntos
Cardiomiopatia Dilatada/enzimologia , Cardiomiopatia Dilatada/genética , Genes Recessivos , Mutação/genética , Peptídeo Sintases/genética , Sequência de Aminoácidos , Animais , Vias Biossintéticas , Cardiomiopatia Dilatada/diagnóstico , Carnitina/análogos & derivados , Carnitina/metabolismo , Pré-Escolar , Coenzima A/biossíntese , Demografia , Drosophila , Estabilidade Enzimática , Feminino , Fibroblastos/metabolismo , Coração/fisiopatologia , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Lactente , Recém-Nascido , Imagem por Ressonância Magnética , Masculino , Panteteína/administração & dosagem , Panteteína/análogos & derivados , Linhagem , Peptídeo Sintases/sangue , Peptídeo Sintases/química , Peptídeo Sintases/deficiência , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/genética
19.
J Inherit Metab Dis ; 41(6): 1293-1294, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29721919

RESUMO

Congenital disorders of glycosylation (CDG) have a broad spectrum of clinical manifestations. They can affect multiple organ systems, including skin and subcutaneous tissue. We report on an infant with severe ichthyosis caused by MPDU1 mutations. The case illustrates that skin manifestations are an important feature of CDG syndromes. Therefore, metabolic investigations should be included in the workup of infantile ichthyosis disorders.


Assuntos
Defeitos Congênitos da Glicosilação/genética , Ictiose/etiologia , Mutação , Proteínas Repressoras/genética , Feminino , Humanos , Lactente , Pele/patologia , Sequenciamento Completo do Exoma
20.
Am J Med Genet A ; 176(7): 1602-1609, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29736960

RESUMO

Intellectual disability (ID) and global developmental delay are closely related; the latter is reserved for children under the age of 5 years as it is challenging to reliably assess clinical severity in this population. ID is a common condition, with up to 1%-3% of the population being affected and leading to a huge social and economic impact. ID is attributed to genetic abnormalities most of the time; however, the exact role of genetic involvement in ID is yet to be determined. Whole exome sequencing (WES) has gained popularity in the workup for ID, and multiple studies have been published examining the diagnostic yield in identification of the disease-causing variant (16%-55%), with the genetic involvement increasing as intelligence quotient decreases. WES has also accelerated novel disease gene discovery in this field. We identified a novel biallelic variant in the KIF16B gene (NM_024704.4:c.3611T > G) in two brothers that may be the cause of their phenotype.


Assuntos
Genes Recessivos , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Cinesina/genética , Mutação , Criança , Exoma , Humanos , Cinesina/química , Masculino , Conformação Proteica , Síndrome , Sequenciamento Completo do Exoma
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