RESUMO
Primary immunodeficiency diseases (PIDs) are a group of more than 400 disorders representing aberrant functioning or development of immune system. Hypopigmentation syndromes also characterize a distinguished cluster of diseases. However, hypopigmentation may also signify a feature of genetic diseases associated with immunodeficiency, such as Chediak-Higashi syndrome, Griscelli syndrome type 2, Hermansky-Pudlak syndrome type 2 and type 10, Vici syndrome, and P14/LAMTOR2 deficiency, all of which are linked with dysfunction in vesicular/endosomal trafficking. Regarding the highly overlapping features, these disorders need a comprehensive examination for prompt diagnosis and effective management. As an aid to clinician, distinguishing the pathophysiology, clinical phenotype, and diagnosis as well as treatment options of the six mentioned PID disorders associated with hypopigmentation are described and discussed in this review.
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Testes Genéticos , Hipopigmentação/diagnóstico , Doenças da Imunodeficiência Primária/diagnóstico , Diagnóstico Diferencial , Humanos , Hipopigmentação/genética , Hipopigmentação/imunologia , Hipopigmentação/terapia , Doenças da Imunodeficiência Primária/genética , Doenças da Imunodeficiência Primária/imunologia , Doenças da Imunodeficiência Primária/terapia , Pigmentação da Pele/genética , Pigmentação da Pele/imunologiaRESUMO
We report on a sibling pair with the EPG5 c.1007A > G mutation who developed a severe form of Vici syndrome and died in infancy. The c.1007A > G (p.Gln336Arg) mutation, affecting the penultimate nucleotide and the splicing of exon 2 is the most common mutation of EPG5 and is typically associated with a less devastating prognosis: cardiomyopathy and cataract are less frequent consequences and the median survival time is 78 months compared to an overall median survival of 42 months. The less severe course related to c.1007A > G was formerly explained by the preserved canonical splicing in 25% of the transcripts. In contrast, we found the messenger RNA encoded by the c.1007A > G allele to be absent, explaining the severe course of the disease. This family provides another example of phenotypic variability related to a differential splicing.
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Agenesia do Corpo Caloso/patologia , Proteínas Relacionadas à Autofagia/genética , Catarata/patologia , Mutação , Splicing de RNA , Proteínas de Transporte Vesicular/genética , Adolescente , Agenesia do Corpo Caloso/genética , Catarata/genética , Progressão da Doença , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Irmãos , Taxa de SobrevidaRESUMO
Autophagy is a fundamental and conserved catabolic pathway that mediates the degradation of macromolecules and organelles in lysosomes. Autophagy is particularly important to postmitotic and metabolically active cells such as neurons. The complex architecture of neurons and their long axons pose additional challenges for efficient recycling of cargo. Not surprisingly autophagy is required for normal central nervous system development and function. Several single-gene disorders of the autophagy pathway have been discovered in recent years giving rise to a novel group of inborn errors of metabolism referred to as congenital disorders of autophagy. While these disorders are heterogeneous, they share several clinical and molecular characteristics including a prominent and progressive involvement of the central nervous system leading to brain malformations, developmental delay, intellectual disability, epilepsy, movement disorders, and cognitive decline. On brain magnetic resonance imaging a predominant involvement of the corpus callosum, the corticospinal tracts and the cerebellum are noted. A storage disease phenotype is present in some diseases, underscoring both clinical and molecular overlaps to lysosomal storage diseases. This review provides an update on the clinical, imaging, and genetic spectrum of congenital disorders of autophagy and highlights the importance of this pathway for neurometabolism and childhood-onset neurological diseases.
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Autofagia/fisiologia , Deficiências do Desenvolvimento/etiologia , Doenças Neurodegenerativas/etiologia , Agenesia do Corpo Caloso/etiologia , Agenesia do Corpo Caloso/genética , Encéfalo/patologia , Catarata/etiologia , Catarata/genética , Criança , Deficiências do Desenvolvimento/genética , Humanos , Imageamento por Ressonância Magnética , Doenças Neurodegenerativas/genética , Proteínas/genética , Paraplegia Espástica Hereditária/etiologia , Paraplegia Espástica Hereditária/genéticaRESUMO
Vici syndrome is a multisystem disorder characterized by agenesis of the corpus callosum, oculocutaneous hypopigmentation, cataracts, cardiomyopathy, combined immunodeficiency, failure to thrive, profound developmental delay, and acquired microcephaly. Most individuals are severely affected and have a markedly reduced life span. Here we describe an 8-year-old boy with a history of developmental delay, agenesis of the corpus callosum, failure to thrive, myopathy, and well-controlled epilepsy. He was initially diagnosed with a mitochondrial disorder, based in part upon nonspecific muscle biopsy findings, but mitochondrial DNA mutation analysis revealed no mutations. Whole exome sequencing revealed compound heterozygosity for two EPG5 variants, inherited in trans. One was a known pathogenic mutation in exon 13 (c.2461C > T, p.Arg821X). The second was reported as a variant of unknown significance found within intron 16, six nucleotides before the exon 17 splice acceptor site (c.3099-6C > G). Reverse transcription-polymerase chain reaction of the EPG5 mRNA showed skipping of exon 17-which maintains an open reading frame-in 77% of the transcript, along with 23% expression of wild-type mRNA suggesting that intronic mutations may affect splicing of the EPG5 gene and result in symptoms. However, the expression of 23% wild-type mRNA may result in a significantly attenuated Vici syndrome phenotype.
Assuntos
Agenesia do Corpo Caloso/diagnóstico , Agenesia do Corpo Caloso/genética , Catarata/diagnóstico , Catarata/genética , Expressão Gênica , Estudos de Associação Genética , Predisposição Genética para Doença , Fenótipo , Proteínas/genética , Proteínas Relacionadas à Autofagia , Biópsia , Regulação para Baixo , Éxons , Heterozigoto , Humanos , Proteínas de Membrana Lisossomal , Masculino , Músculos/metabolismo , Músculos/patologia , Mutação , RNA Mensageiro , Análise de Sequência de DNA , Proteínas de Transporte Vesicular , Sequenciamento do ExomaRESUMO
Vici syndrome is one of the most extensive inherited human multisystem disorders and due to recessive mutations in EPG5 encoding a key autophagy regulator with a crucial role in autophagosome-lysosome fusion. The condition presents usually early in life, with features of severe global developmental delay, profound failure to thrive, (acquired) microcephaly, callosal agenesis, cataracts, cardiomyopathy, hypopigmentation, and combined immunodeficiency. Clinical course is variable but usually progressive and associated with high mortality. Here, we present a fetus, offspring of consanguineous parents, in whom callosal agenesis and other developmental brain abnormalities were detected on fetal ultrasound scan (US) and subsequent MRI scan in the second trimester. Postmortem examination performed after medically indicated termination of pregnancy confirmed CNS abnormalities and provided additional evidence for skin hypopigmentation, nascent cataracts, and hypertrophic cardiomyopathy. Genetic testing prompted by a suggestive combination of features revealed a homozygous EPG5 mutation (c.5870-1G>A) predicted to cause aberrant splicing of the EPG5 transcript. Our findings expand the phenotypical spectrum of EPG5-related Vici syndrome and suggest that this severe condition may already present in utero. While callosal agenesis is not an uncommon finding in fetal medicine, additional presence of hypopigmentation, cataracts and cardiomyopathy is rare and should prompt EPG5 testing.
Assuntos
Agenesia do Corpo Caloso/genética , Síndrome de Aicardi/genética , Catarata/genética , Síndromes de Imunodeficiência/genética , Proteínas/genética , Idade de Início , Agenesia do Corpo Caloso/diagnóstico por imagem , Agenesia do Corpo Caloso/fisiopatologia , Síndrome de Aicardi/fisiopatologia , Proteínas Relacionadas à Autofagia , Autopsia , Catarata/diagnóstico por imagem , Catarata/fisiopatologia , Consanguinidade , Feto/diagnóstico por imagem , Feto/fisiopatologia , Humanos , Hipopigmentação/genética , Hipopigmentação/fisiopatologia , Síndromes de Imunodeficiência/diagnóstico por imagem , Síndromes de Imunodeficiência/fisiopatologia , Proteínas de Membrana Lisossomal , Imageamento por Ressonância Magnética , Mutação , Fenótipo , Diagnóstico Pré-Natal , Proteínas de Transporte VesicularRESUMO
Vici syndrome is a progressive neurodevelopmental multisystem disorder due to recessive mutations in the key autophagy gene EPG5. We report genetic, clinical, neuroradiological, and neuropathological features of 50 children from 30 families, as well as the neuronal phenotype of EPG5 knock-down in Drosophila melanogaster. We identified 39 different EPG5 mutations, most of them truncating and predicted to result in reduced EPG5 protein. Most mutations were private, but three recurrent mutations (p.Met2242Cysfs*5, p.Arg417*, and p.Gln336Arg) indicated possible founder effects. Presentation was mainly neonatal, with marked hypotonia and feeding difficulties. In addition to the five principal features (callosal agenesis, cataracts, hypopigmentation, cardiomyopathy, and immune dysfunction), we identified three equally consistent features (profound developmental delay, progressive microcephaly, and failure to thrive). The manifestation of all eight of these features has a specificity of 97%, and a sensitivity of 89% for the presence of an EPG5 mutation and will allow informed decisions about genetic testing. Clinical progression was relentless and many children died in infancy. Survival analysis demonstrated a median survival time of 24 months (95% confidence interval 0-49 months), with only a 10th of patients surviving to 5 years of age. Survival outcomes were significantly better in patients with compound heterozygous mutations (P = 0.046), as well as in patients with the recurrent p.Gln336Arg mutation. Acquired microcephaly and regression of skills in long-term survivors suggests a neurodegenerative component superimposed on the principal neurodevelopmental defect. Two-thirds of patients had a severe seizure disorder, placing EPG5 within the rapidly expanding group of genes associated with early-onset epileptic encephalopathies. Consistent neuroradiological features comprised structural abnormalities, in particular callosal agenesis and pontine hypoplasia, delayed myelination and, less frequently, thalamic signal intensity changes evolving over time. Typical muscle biopsy features included fibre size variability, central/internal nuclei, abnormal glycogen storage, presence of autophagic vacuoles and secondary mitochondrial abnormalities. Nerve biopsy performed in one case revealed subtotal absence of myelinated axons. Post-mortem examinations in three patients confirmed neurodevelopmental and neurodegenerative features and multisystem involvement. Finally, downregulation of epg5 (CG14299) in Drosophila resulted in autophagic abnormalities and progressive neurodegeneration. We conclude that EPG5-related Vici syndrome defines a novel group of neurodevelopmental disorders that should be considered in patients with suggestive features in whom mitochondrial, glycogen, or lysosomal storage disorders have been excluded. Neurological progression over time indicates an intriguing link between neurodevelopment and neurodegeneration, also supported by neurodegenerative features in epg5-deficient Drosophila, and recent implication of other autophagy regulators in late-onset neurodegenerative disease.
Assuntos
Agenesia do Corpo Caloso/diagnóstico , Agenesia do Corpo Caloso/genética , Autofagia/genética , Catarata/diagnóstico , Catarata/genética , Transtornos do Neurodesenvolvimento/diagnóstico , Transtornos do Neurodesenvolvimento/genética , Proteínas/genética , Agenesia do Corpo Caloso/complicações , Animais , Proteínas Relacionadas à Autofagia , Catarata/complicações , Pré-Escolar , Estudos Transversais , Drosophila melanogaster , Feminino , Hipocampo/patologia , Humanos , Proteínas de Membrana Lisossomal , Masculino , Mutação/genética , Transtornos do Neurodesenvolvimento/complicações , Estudos Retrospectivos , Proteínas de Transporte VesicularRESUMO
Vici syndrome (OMIM 242840) is a rare syndrome and since its initial description by Vici et al. [1988], only 29 cases have been reported. We describe two brothers from healthy consanguineous Turkish parents with psychomotor delay, congenital bilateral cataracts, high palate, long philtrum, micrognathia, fair hair, and skin. They both had general hypotonia and elevated muscle enzymes. Magnetic resonance imaging (MRI) of the brain confirmed agenesis of corpus callosum in both patients. Secundum type atrial septal defect (in Patient 1) and mild mitral, tricuspid, and pulmonary insufficiency (in Patient 2) were detected by echocardiographic examination. Immunological studies were normal, as were chromosome karyotype analyses (46, XY). Both children had bilateral cutaneous syndactyly between second and third toes and also bilateral sensorineural hearing loss. Patient 1 had poor feeding and regurgitation necessitating a feeding tube; mild laryngomalacia was subsequently detected by bronchoscopy. Mutation analysis in patient 2 showed a homozygous p.R2483* (c.7447C > T) mutation in EPG5 gene. We report a summary of the clinical findings in our patients and 29 cases from the literature.
Assuntos
Anormalidades Múltiplas/genética , Agenesia do Corpo Caloso/genética , Encéfalo/anormalidades , Catarata/genética , Anormalidades Craniofaciais/genética , Atrofia Muscular/genética , Consanguinidade , Família , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Pais , IrmãosRESUMO
Vici syndrome is a rare congenital disorder first described in 1988. To date, 31 cases have been reported in the literature. The characteristic features of this syndrome include: agenesis of the corpus callosum, albinism, cardiomyopathy, variable immunodeficiency, cataracts, and myopathy. We report two Hispanic sisters with genetically confirmed Vici syndrome who both developed Idiopathic Thrombocytopenic Purpura. To our knowledge, this is an immunologic process that has been previously undescribed within the phenotype of Vici syndrome and should be added to the spectrum of variable immune dysregulation that can be found in these patients.
Assuntos
Agenesia do Corpo Caloso/genética , Catarata/genética , Proteínas/genética , Púrpura Trombocitopênica Idiopática/genética , Agenesia do Corpo Caloso/complicações , Agenesia do Corpo Caloso/fisiopatologia , Proteínas Relacionadas à Autofagia , Catarata/complicações , Catarata/fisiopatologia , Códon sem Sentido , Corpo Caloso/crescimento & desenvolvimento , Corpo Caloso/fisiopatologia , Feminino , Humanos , Lactente , Recém-Nascido , Proteínas de Membrana Lisossomal , Púrpura Trombocitopênica Idiopática/complicações , Púrpura Trombocitopênica Idiopática/fisiopatologia , Proteínas de Transporte VesicularRESUMO
Vici syndrome is a rare autosomal recessively inherited multisystem disorder characterized by agenesis of the corpus callosum, cataracts, cardiomyopathy, combined immunodeficiency, psychomotor delay, and hypopigmentation. Cullup et al. recently identified mutations in the gene EPG5 as the cause of Vici syndrome. EPG5 is involved in autophagy, an evolutionarily conserved lysosomal degradation process that is essential for cell homeostasis. Following the first description in 1988 by Vici et al., 24 other cases of Vici syndrome have been published with variable expression of the defining features. Here, we report on a further case of Vici syndrome with a homozygous truncating mutation of EPG5, identified by whole-exome sequencing. The mutation in our patient is the first reported affecting the penultimate exon of EPG5 and presenting with typical clinical manifestations of Vici syndrome. Additionally, we present a detailed clinical analysis of Vici syndrome comprising all cases previously described in the literature.
Assuntos
Agenesia do Corpo Caloso/genética , Agenesia do Corpo Caloso/patologia , Catarata/genética , Catarata/patologia , Proteínas/genética , Proteínas Relacionadas à Autofagia , Sequência de Bases , Exoma/genética , Éxons/genética , Evolução Fatal , Genes Recessivos/genética , Humanos , Lactente , Irã (Geográfico) , Proteínas de Membrana Lisossomal , Dados de Sequência Molecular , Análise de Sequência de DNA , Proteínas de Transporte VesicularRESUMO
BACKGROUND: Vici syndrome (VICIS) is a congenital disorder characterized by agenesis of the corpus callosum, cataracts, hypopigmentation, cardiomyopathy, combined immunodeficiency, microcephaly, and failure to thrive. This study aimed to elucidate the number of patients with VICIS, its clinical characteristics and relevant genetic information in Japan. METHODS: After developing diagnostic criteria for VICIS, we conducted a nationwide questionnaire-based survey of VICIS in Japan. In the initial survey, we investigated the number of VICIS patients who fulfilled definite or probable criteria. The second survey was used to obtain detailed clinical and genetic information of VICIS from institutions that responded to the initial survey. RESULTS: Clinical information was available for 15 patients (12 definite, three probable). As of October 2023, nine patients (60%) were alive and six (40%) had died. All patients presented with developmental delay, agenesis of the corpus callosum, elevated serum aspartate/alanine aminotransferase, hypopigmentation and hypotonia. Developmental delay was profound. Most patients developed recurrent infection, high-arched palate, epilepsy, failure to thrive, and microcephaly. Cardiomyopathy and cataracts, both initially described as principal features in VICIS, were notably uncommon in our study. Based on the information collected, all 14 patients for whom information was available received home medical care: 11 (79%) received tube feeding, three (21%) required noninvasive ventilation, four (29%) required tracheostomy, and four (29%) required home subcutaneous immunoglobulin administration. CONCLUSION: This study revealed for the first time the nationwide status of patients with VICIS in Japan. The mortality rate of patients with VICIS is as high as 40%, and almost all VICIS patients require various forms of home medical care, necessitating comprehensive management. Additionally, we identified one adult patient, underscoring the need for comprehensive medical management extending into adulthood for patients with VICIS.
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Introduction: Vici syndrome is an ultra-rare, congenital disorder of autophagy characterized by agenesis of the corpus callosum, cataracts, cardiomyopathy, combined immunodeficiency, developmental delay, and hypopigmentation. Patients usually present in the neonatal period or infancy with profound hypotonia, based on information available from the nearly 100 cases reported to date. Case Presentation: We present 3 new cases of Vici syndrome confirmed by genetic analysis of EPG5 gene. The 3 male patients had neonatal hypotonia, progressive microcephaly, psychomotor retardation, recurrent respiratory tract infections, optic atrophy, and failure to thrive, but no cataracts or hepatomegaly. Three disease-causing variants in homozygous state were detected in the EPG5 gene: two novel c.1652C>T and c.7557+2T>C forms; and one previously reported c.7447C>T. The patient, who was homozygous for the c.1652C>T mutation, presented with neonatal onset seizures that had not been reported previously. Discussion/Conclusion: The present study provides data for the evaluation of the natural history and genotype-phenotype correlations for treatment options that are expected to be available in the future.
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Vici syndrome (OMIM 242840) is a very rare autosomal recessive multisystem disorder first described in 1988. In 2013, bi-allelic loss-of-function mutations in EPG5 were reported to cause Vici syndrome. Five principal diagnostic features of Vici syndrome have been proposed: agenesis of the corpus callosum, cataracts, cardiomyopathy, hypopigmentation, and combined immunodeficiency. We identified 15 patients carrying a homozygous founder missense variant in EPG5 who all exhibit a less severe clinical phenotype than classic Vici syndrome. All 15 show typical brain abnormalities on MRI. The homozygous founder variant in EPG5 they carry results in a shorter in-frame transcript and truncated, but likely still residual, EPG5 protein. We speculate that the residual EPG5 protein explains their attenuated phenotype, which is consistent with two previous observations that low expression of EPG5 can lead to an attenuated Vici syndrome phenotype. We propose renaming this condition EPG5-related neurodevelopmental disorder to emphasize the clinical variability of patients with bi-allelic mutations in EPG5.
Assuntos
Catarata , Humanos , Catarata/genética , Fenótipo , Homozigoto , Corpo Caloso , Proteínas Relacionadas à Autofagia , Proteínas de Transporte Vesicular/genéticaRESUMO
Platelets mediate central aspects of host responses during sepsis, an acute profoundly systemic inflammatory response due to infection. Macroautophagy/autophagy, which mediates critical aspects of cellular responses during inflammatory conditions, is known to be a functional cellular process in anucleate platelets, and is essential for normal platelet functions. Nevertheless, how sepsis may alter autophagy in platelets has never been established. Using platelets isolated from septic patients and matched healthy controls, we show that during clinical sepsis, the number of autophagosomes is increased in platelets, most likely due to an accumulation of autophagosomes, some containing mitochondria and indicative of mitophagy. Therefore, autophagy induction or early-stage autophagosome formation (as compared to decreased later-stage autophagosome maturation or autophagosome-late endosome/lysosome fusion) is normal or increased. This was consistent with decreased fusion of autophagosomes with lysosomes in platelets. EPG5 (ectopic P-granules autophagy protein 5 homolog), a protein essential for normal autophagy, expression did increase, while protein-protein interactions between EPG5 and MAP1LC3/LC3 (which orchestrate the fusion of autophagosomes and lysosomes) were significantly reduced in platelets during sepsis. Furthermore, data from a megakaryocyte model demonstrate the importance of TLR4 (toll like receptor 4), LPS-dependent signaling for regulating this mechanism. Similar phenotypes were also observed in platelets isolated from a patient with Vici syndrome: an inherited condition caused by a naturally occurring, loss-of-function mutation in EPG5. Together, we provide evidence that autophagic functions are aberrant in platelets during sepsis, due in part to reduced EPG5-LC3 interactions, regulated by TLR4 engagement, and the resultant accumulation of autophagosomes.Abbreviations: ACTB: beta actin; CLP: cecal ligation and puncture; Co-IP: co-immunoprecipitation; DAP: death associated protein; DMSO: dimethyl sulfoxide; EPG5: ectopic P-granules autophagy protein 5 homolog; ECL: enhanced chemiluminescence; HBSS: Hanks' balanced salt solution; HRP: horseradish peroxidase; ICU: intensive care unit; LPS: lipopolysaccharide; LAMP1: lysosomal associated membrane protein 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; MKs: megakaryocytes; PFA: paraformaldehyde; PBS: phosphate-buffered saline; PLA: proximity ligation assay; pRT-PCR: quantitative real-time polymerase chain reaction; RT: room temperature; SQSTM1/p62: sequestosome 1; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; TLR4: toll like receptor 4; TEM: transmission electron microscopy; WGA: wheat germ agglutinin.
Assuntos
Proteínas Relacionadas à Autofagia , Autofagia , Plaquetas , Proteínas Associadas aos Microtúbulos , Sepse , Autofagossomos/metabolismo , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Plaquetas/metabolismo , Humanos , Lipopolissacarídeos , Lisossomos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Sepse/metabolismo , Receptor 4 Toll-Like/metabolismo , Proteínas de Transporte Vesicular/metabolismoRESUMO
Introduction: Vici Syndrome is a rare, severe, neurodevelopmental/neurodegenerative disorder with multi-systemic manifestations presenting in infancy. It is mainly characterized by global developmental delay, seizures, agenesis of the corpus callosum, hair and skin hypopigmentation, bilateral cataract, and varying degrees of immunodeficiency, among other features. Vici Syndrome is caused by biallelic pathogenic variants in EPG5, resulting in impaired autophagy. Thus far, the condition has been reported in less than a hundred individuals. Objective and Methods: We aimed to characterize the clinical and molecular findings in individuals harboring biallelic EPG5 variants, recruited from four medical centers in Israel. Furthermore, we aimed to utilize a machine learning-based tool to assess facial features of Vici syndrome. Results: Eleven cases of Vici Syndrome from five unrelated families, one of which was diagnosed prenatally with subsequent termination of pregnancy, were recruited. A total of five disease causing variants were detected in EPG5: two novel: c.2554-5A>G and c.1461delC; and 3 previously reported: c.3447G>A, c.5993C>G, and c.1007A>G, the latter previously identified in several patients of Ashkenazi-Jewish (AJ) descent. Amongst 140,491 individuals screened by the Dor Yeshorim Program, we show that the c.1007A>G variant has an overall carrier frequency of 0.45% (1 in 224) among AJ individuals. Finally, based on two-dimensional facial photographs of individuals with Vici syndrome (n = 19), a composite facial mask was created using the DeepGestalt algorithm, illustrating facial features typical of this disorder. Conclusion: We report on ten children and one fetus from five unrelated families, affected with Vici syndrome, and describe prenatal and postnatal characteristics. Our findings contribute to the current knowledge regarding the molecular basis and phenotypic features of this rare syndrome. Additionally, the deep learning-based facial gestalt adds to the clinician's diagnostic toolbox and may aid in facilitating identification of affected individuals.
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AIM: To report the earliest diagnosis of Vici syndrome in a three-week-old Omani girl. METHODS: A three-week-old baby girl with blond hair and agenesis of the corpus callosum was born to consanguineous parents. An older sibling with similar findings had died at the age of six months with recurrent seizures and aspiration pneumonia without a diagnosis of the underlying systemic condition. After a standard ophthalmic and comprehensive systemic evaluation, full sequencing of the EPG5 gene was carried out. RESULTS: The findings of bilateral anterior polar cataracts and oculocutaneous albinism in the child with agenesis of corpus callosum raised a suspicion of Vici syndrome. Immunology, neurology, cardiology, and genetic consultations were requested and revealed the presence of immunodeficiency, psychomotor retardation, and hypertrophic cardiomyopathy. Full sequencing of the EPG5 gene led to the detection of a homozygous c.6084 G > A (Trp2028Ter) mutation, confirming the diagnosis of Vici syndrome. Parental heterozygosity was confirmed. On follow-up, progressive microcephaly, failure to thrive, and significant developmental delay were noted, and a clinical decision not to resuscitate was made at the age of 22 months. CONCLUSIONS: We report the earliest diagnosis of Vici syndrome in the literature. Ophthalmic findings are a cardinal feature of this condition. The diagnosis should be considered in infants with hallmark features of oculocutaneous albinism, cataracts, and agenesis of the corpus callosum. Vici syndrome has a very poor prognosis due to progressive neuroregression superimposed on the neurodevelopmental anomaly.
Assuntos
Agenesia do Corpo Caloso/diagnóstico , Agenesia do Corpo Caloso/genética , Albinismo Oculocutâneo/diagnóstico , Proteínas Relacionadas à Autofagia/genética , Catarata/diagnóstico , Polimorfismo de Nucleotídeo Único/genética , Proteínas de Transporte Vesicular/genética , Albinismo Oculocutâneo/genética , Catarata/genética , Consanguinidade , Diagnóstico Precoce , Evolução Fatal , Feminino , Humanos , Recém-Nascido , Imageamento por Ressonância Magnética , OmãRESUMO
BACKGROUND: Vici syndrome (VICIS) refers to a clinical spectrum of multiple organ systems characterized by corpus callosum agenesis, hypopigmentation, cataracts, cardiomyopathy and immunodeficiency. The aims of this study were to describe detailed clinical and molecular features of two Chinese female siblings and to review several previous findings. METHODS: Targeted sequencing panel involving all known disease-causing genes of monogenic disorders combined with Sanger sequencing validation were performed to identify the likely pathogenic sequence variants of the proband with VICIS. RESULTS: The proband diagnosed as VICIS presented with neonatal pneumonia, myocardial damage, hypotonia, maxillofacial malformations, hearing impairment, failure to thrive and died 40 days after birth. Two novel missense variants in ectopic P-granules autophagy protein 5 homologue (EPG5, NM_020964.3) were identified in this proband. The two likely pathogenic variants c.1609G > A (p.(E537K)) and c.5764C>G (p.(P1922A)) were assessed as damaging by bioinformatic analysis. As these variants were absent in 150 unrelated Chinese normal controls and inherited from asymptomatic parents in the co-segregation analysis, the compound heterozygous EPG5 variants were responsible for the clinical features of this patient. Finally, she was genetically diagnosed with VICIS. CONCLUSIONS: To our knowledge, this is the first Chinese case of VICIS. Our report identified novel compound heterozygous EPG5 sequence variants in the proband with VICIS, highlighting the rarity and high mortality rate of VICIS and emphasizing on the importance of high-throughput sequencing in confirmed diagnosis of monogenic diseases, which could further facilitate the development of genetic counselling and prenatal diagnosis.
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Agenesia do Corpo Caloso/genética , Proteínas Relacionadas à Autofagia/genética , Catarata/genética , Proteínas de Transporte Vesicular/genética , Feminino , Humanos , Lactente , Infodemia , LinhagemRESUMO
BACKGROUND: Oligosaccharidoses are storage disorders due to enzymatic defects involved in the breakdown of the oligosaccharidic component of glycosylated proteins. The defect cause the accumulation of oligosaccharides (OS) and, depending on the lacking enzyme, results in characteristic profiles which are helpful for the diagnosis. We developed a new tandem mass spectrometry method for the screening of urinary OS which was applied to identify a large panel of storage disorders. METHODS: The method was set-up in urine and dried urine spots (DUS). Samples were analysed, without derivatization and using maltoheptaose as internal standard, by UHPLC-MS/MS with MRM acquisition of target OS transitions, including Glc4, the biomarker of Pompe disease. The chromatographic run was < 30 min. Samples from patients with known storage disorders were used for clinical validation. RESULTS: The method allowed to confirm the diagnosis of oligosaccharidoses (sialidosis, α-/ß-mannosidosis, fucosidosis, aspartylglucosaminuria) and of GM1 and GM2 (Sandhoff type) gangliosidosis, by detecting specific OS profiles. In other storage disorders (mucolipidosis II and III, mucopolysaccharidosis type IVB) the analyisis revealed abnormal OS excretion with non-specific profiles. Besides Pompe disease, the tetrasaccharide Glc4 was increased also in disorders of autophagy (Vici syndrome, Yunis-Varon syndrome, and Danon disease) presenting cardiomuscular involvement with glycogen storage. Overall, results showed a clear separation between patients and controls, both in urine and in DUS. CONCLUSION: This new UHPLC/MS-MS method, which is suitable for rapid and easy screening of OS in urine and DUS, expands the detection of storage disorders from oligosaccharidoses to other diseases, including the novel category of inherited disorders of autophagy.
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Fucosidose , Doença de Depósito de Glicogênio Tipo II , Doenças por Armazenamento dos Lisossomos , Cromatografia Líquida de Alta Pressão , Humanos , Doenças por Armazenamento dos Lisossomos/diagnóstico , Oligossacarídeos , Espectrometria de Massas em TandemRESUMO
BACKGROUND: Vici syndrome is a rare autosomal recessive disease with phenotypically heterogeneous presentation. Characteristic features of the disease are oculocutaneous albinism, corpus callosum agenesis, cataract, cardiomyopathy, and immunodeficiency. CASE: Here we report two Turkish patients with Vici syndrome. One of these patients had a novel mutation in EPG5 and presented with idiopathic thrombocytopenic purpura (ITP) and maculopapular rashes similar to Stevens-Johnson syndrome, which has been previously reported in only a few cases in the literature. CONCLUSION: Vici syndrome presents with a typical phenotype which may facilitate diagnosis for infants with multisystemic disorders. ITP and maculopapular rashes might be added to the spectrum of findings of patients with Vici syndrome.
Assuntos
Albinismo , Catarata , Agenesia do Corpo Caloso/diagnóstico , Agenesia do Corpo Caloso/genética , Proteínas Relacionadas à Autofagia , Humanos , Proteínas de Transporte VesicularRESUMO
The EPG5 protein is a RAB7A effector involved in fusion specificity between autophagosomes and late endosomes or lysosomes during macroautophagy/autophagy. Mutations in the human EPG5 gene cause a rare and severe multisystem disorder called Vici syndrome. In this work, we show that zebrafish epg5-/- mutants from both heterozygous and incrossed homozygous matings are viable and can develop to the age of sexual maturity without conspicuous defects in external appearance. In agreement with the dysfunctional autophagy of Vici syndrome, western blot revealed higher levels of the Lc3-II autophagy marker in epg5-/- mutants with respect to wild type controls. Moreover, starvation elicited higher accumulation of Lc3-II in epg5-/- than in wild type larvae, together with a significant reduction of skeletal muscle birefringence. Accordingly, muscle ultrastructural analysis revealed accumulation of degradation-defective autolysosomes in starved epg5-/- mutants. By aging, epg5-/- mutants showed impaired motility and muscle thinning, together with accumulation of non-degradative autophagic vacuoles. Furthermore, epg5-/- adults displayed morphological alterations in gonads and heart. These findings point at the zebrafish epg5 mutant as a valuable model for EPG5-related disorders, thus providing a new tool for dissecting the contribution of EPG5 on the onset and progression of Vici syndrome as well as for the screening of autophagy-stimulating drugs. Abbreviations: ATG: autophagy related; cDNA: complementary DNA; DIG: digoxigenin; dpf: days post-fertilization; EGFP: enhanced green fluorescent protein; EPG: ectopic P granules; GFP: green fluorescent protein; hpf: hours post-fertilization; IL1B: interleukin 1 beta; Lc3-II: lipidated Lc3; mpf: months post-fertilization; mRNA: messenger RNA; NMD: nonsense-mediated mRNA decay; PCR: polymerase chain reaction; qPCR: real time-polymerase chain reaction; RAB7A/RAB7: RAB7a, member RAS oncogene family; RACE: rapid amplification of cDNA ends; RFP: red fluorescent protein; RT-PCR: reverse transcriptase-polymerase chain reaction; SEM: standard error of the mean; sgRNA: guide RNA; UTR: untranslated region; WMISH: whole mount in situ hybridization; WT: wild type.
Assuntos
Agenesia do Corpo Caloso/metabolismo , Proteínas Relacionadas à Autofagia/metabolismo , Catarata/metabolismo , Técnicas de Inativação de Genes , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/genética , Sequência de Aminoácidos , Animais , Autofagossomos/metabolismo , Proteínas Relacionadas à Autofagia/química , Proteínas Relacionadas à Autofagia/genética , Sequência de Bases , Regulação da Expressão Gênica no Desenvolvimento , Células Caliciformes/patologia , Intestinos/patologia , Intestinos/ultraestrutura , Larva/ultraestrutura , Lisossomos/metabolismo , Fusão de Membrana , Modelos Biológicos , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Mutagênese/genética , Mutação/genética , Especificidade de Órgãos , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/química , Proteínas de Peixe-Zebra/genéticaRESUMO
INTRODUCTION: Vici syndrome, a rare autosomal recessive disorder, was first described in 1988 by Vici et al. Only 78 cases have been reported to date. The syndrome is characterised by agenesis of the corpus callosum, hypopigmentation, cardiomyopathy, progressive failure to thrive, dysmorphic features, immunodeficiency and cataracts. Mutations in the gene epg5 have been identified as the cause of Vici syndrome. CASE DESCRIPTION: The parents are a consanguineous Saudi couple with two other children diagnosed with Gaucher disease. The patient was born at term and in the first 5 months had many hospital admissions for a recurrent chest infection. Physical examination, investigations and imaging studies revealed that the patient had agenesis of the corpus callosum, cataracts, psychomotor delay, immunodeficiency and hypopigmentation. The initial echocardiogram was normal. At 7 months, genetic testing confirmed the diagnosis of Vici syndrome with a c.3693G>Ap (Gln1231Gln) mutation in the gene EPG5. The patient developed a chest infection and was admitted to the pediatric intensive care unit. An echocardiogram was repeated and showed significant left ventricular dilation with a Z-score of 3.1, moderate mitral and tricuspid regurgitation, and depressed ventricular function with a fractional shortening of 17% and ejection fraction 37%. The patient's condition deteriorated, and he died aged 8 months. CONCLUSION: The symptoms of extensive system involvement in Vici syndrome have been present in the majority of reported cases and should prompt careful evaluation of this syndrome when such symptoms are present in an infant. In confirmed cases, close monitoring of the immune status and cardiac function, the two main causes of death among Vici syndrome patients, is vital to prevent rapid deterioration and improve life expectancy.