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1.
Brain ; 143(1): 55-68, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31834374

RESUMO

MN1 encodes a transcriptional co-regulator without homology to other proteins, previously implicated in acute myeloid leukaemia and development of the palate. Large deletions encompassing MN1 have been reported in individuals with variable neurodevelopmental anomalies and non-specific facial features. We identified a cluster of de novo truncating mutations in MN1 in a cohort of 23 individuals with strikingly similar dysmorphic facial features, especially midface hypoplasia, and intellectual disability with severe expressive language delay. Imaging revealed an atypical form of rhombencephalosynapsis, a distinctive brain malformation characterized by partial or complete loss of the cerebellar vermis with fusion of the cerebellar hemispheres, in 8/10 individuals. Rhombencephalosynapsis has no previously known definitive genetic or environmental causes. Other frequent features included perisylvian polymicrogyria, abnormal posterior clinoid processes and persistent trigeminal artery. MN1 is encoded by only two exons. All mutations, including the recurrent variant p.Arg1295* observed in 8/21 probands, fall in the terminal exon or the extreme 3' region of exon 1, and are therefore predicted to result in escape from nonsense-mediated mRNA decay. This was confirmed in fibroblasts from three individuals. We propose that the condition described here, MN1 C-terminal truncation (MCTT) syndrome, is not due to MN1 haploinsufficiency but rather is the result of dominantly acting C-terminally truncated MN1 protein. Our data show that MN1 plays a critical role in human craniofacial and brain development, and opens the door to understanding the biological mechanisms underlying rhombencephalosynapsis.


Assuntos
Anormalidades Múltiplas/genética , Anormalidades Craniofaciais/genética , Deficiência Intelectual/genética , Transtornos do Desenvolvimento da Linguagem/genética , Malformações do Sistema Nervoso/genética , Transativadores/genética , Proteínas Supressoras de Tumor/genética , Anormalidades Múltiplas/diagnóstico por imagem , Adolescente , Artéria Basilar/anormalidades , Artéria Basilar/diagnóstico por imagem , Artérias Carótidas/anormalidades , Artérias Carótidas/diagnóstico por imagem , Vermis Cerebelar/anormalidades , Vermis Cerebelar/diagnóstico por imagem , Cerebelo/anormalidades , Cerebelo/diagnóstico por imagem , Criança , Pré-Escolar , Estudos de Coortes , Hibridização Genômica Comparativa , Anormalidades Craniofaciais/diagnóstico por imagem , Feminino , Fibroblastos/metabolismo , Humanos , Imageamento Tridimensional , Lactente , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mutação , Malformações do Sistema Nervoso/diagnóstico por imagem , Degradação do RNAm Mediada por Códon sem Sentido , Polimicrogiria/diagnóstico por imagem , Polimicrogiria/genética , RNA-Seq , Reação em Cadeia da Polimerase em Tempo Real , Síndrome , Tomografia Computadorizada por Raios X , Sequenciamento do Exoma , Sequenciamento Completo do Genoma
2.
Bioorg Med Chem Lett ; 28(6): 993-996, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29501395

RESUMO

Sesquiterpene compounds are widely known for their numerous pharmacological activities. Herein the focus of the authors was on α-Santonin, a sesquiterpene lactone from the Artemisia genus: the aim was to determine whether α-Santonin could be considered in the treatment of inflammation and pain. To this purpose, a small series of derivatives was designed and screened in silico against the enzyme COX-2 along with the parent compound. Drug-likeness parameters were also assessed. The compounds were eventually synthesized, and few were tested to determine their efficacy in the inhibition of COX-2 activity and expression. Overall, compound A2 was the only one with a detectable inhibitory potential of COX-2 activity whilst two of its ether derivatives demonstrated improved ability in the inhibition of COX-2 expression.


Assuntos
Inibidores de Ciclo-Oxigenase 2/farmacologia , Ciclo-Oxigenase 2/metabolismo , Desenho de Fármacos , Santonina/farmacologia , Inibidores de Ciclo-Oxigenase 2/síntese química , Inibidores de Ciclo-Oxigenase 2/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Santonina/síntese química , Santonina/química , Relação Estrutura-Atividade
3.
J Inherit Metab Dis ; 40(1): 21-48, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27905001

RESUMO

BACKGROUND: Remethylation defects are rare inherited disorders in which impaired remethylation of homocysteine to methionine leads to accumulation of homocysteine and perturbation of numerous methylation reactions. OBJECTIVE: To summarise clinical and biochemical characteristics of these severe disorders and to provide guidelines on diagnosis and management. DATA SOURCES: Review, evaluation and discussion of the medical literature (Medline, Cochrane databases) by a panel of experts on these rare diseases following the GRADE approach. KEY RECOMMENDATIONS: We strongly recommend measuring plasma total homocysteine in any patient presenting with the combination of neurological and/or visual and/or haematological symptoms, subacute spinal cord degeneration, atypical haemolytic uraemic syndrome or unexplained vascular thrombosis. We strongly recommend to initiate treatment with parenteral hydroxocobalamin without delay in any suspected remethylation disorder; it significantly improves survival and incidence of severe complications. We strongly recommend betaine treatment in individuals with MTHFR deficiency; it improves the outcome and prevents disease when given early.


Assuntos
Metilação/efeitos dos fármacos , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Proteínas Proto-Oncogênicas c-cbl/deficiência , Vitamina B 12/farmacologia , Vitamina B 12/uso terapêutico , Animais , Homocisteína/genética , Humanos , Metionina/genética
4.
J Inherit Metab Dis ; 39(3): 331-340, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27038030

RESUMO

BACKGROUND: Arginase 1 (ARG1) deficiency is a rare urea cycle disorder (UCD). This hypothesis-generating study explored clinical phenotypes, metabolic profiles, molecular genetics, and treatment approaches in a cohort of children and adults with ARG1 deficiency to add to our understanding of the underlying pathophysiology. METHODS: Clinical data were retrieved retrospectively from physicians using a questionnaire survey. Plasma aminoacids, guanidinoacetate (GAA), parameters indicating oxidative stress and nitric oxide (NO) synthesis as well as asymmetric dimethylarginine (ADMA) were measured at a single study site. RESULTS: Nineteen individuals with ARG1 deficiency and 19 matched controls were included in the study. In patients, paraparesis, cognitive impairment, and seizures were significantly associated suggesting a shared underlying pathophysiology. In patients plasma GAA exceeded normal ranges and plasma ADMA was significantly elevated. Compared to controls, nitrate was significantly higher, and the nitrite:nitrate ratio significantly lower in subjects with ARG1 deficiency suggesting an advantage for NO synthesis by inducible NO synthase (iNOS) over endothelial NOS (eNOS). Logistic regression revealed no significant impact of any of the biochemical parameters (including arginine, nitrates, ADMA, GAA, oxidative stress) or protein restriction on long-term outcome. CONCLUSION: Three main hypotheses which must be evaluated in a hypothesis driven confirmatory study are delineated from this study: 1) clinical manifestations in ARG1 deficiency are not correlated with arginine, protein intake, ADMA, nitrates or oxidative stress. 2) GAA is elevated and may be a marker or an active part of the pathophysiology of ARG1 deficiency. 3) Perturbations of NO metabolism merit future attention in ARG1 deficiency.


Assuntos
Arginase/genética , Arginase/metabolismo , Distúrbios Congênitos do Ciclo da Ureia/sangue , Distúrbios Congênitos do Ciclo da Ureia/genética , Distúrbios Congênitos do Ciclo da Ureia/metabolismo , Adolescente , Adulto , Aminoácidos/sangue , Arginina/análogos & derivados , Arginina/metabolismo , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Glicina/análogos & derivados , Glicina/sangue , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo/fisiologia , Fenótipo , Estudos Retrospectivos , Adulto Jovem
5.
Brain ; 138(Pt 3): 517-39, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25636970

RESUMO

Several single gene disorders share clinical and radiologic characteristics with multiple sclerosis and have the potential to be overlooked in the differential diagnostic evaluation of both adult and paediatric patients with multiple sclerosis. This group includes lysosomal storage disorders, various mitochondrial diseases, other neurometabolic disorders, and several other miscellaneous disorders. Recognition of a single-gene disorder as causal for a patient's 'multiple sclerosis-like' phenotype is critically important for accurate direction of patient management, and evokes broader genetic counselling implications for affected families. Here we review single gene disorders that have the potential to mimic multiple sclerosis, provide an overview of clinical and investigational characteristics of each disorder, and present guidelines for when clinicians should suspect an underlying heritable disorder that requires diagnostic confirmation in a patient with a definite or probable diagnosis of multiple sclerosis.


Assuntos
Diagnóstico Diferencial , Doenças Mitocondriais , Esclerose Múltipla/complicações , Humanos , Doenças Mitocondriais/complicações , Doenças Mitocondriais/diagnóstico , Doenças Mitocondriais/genética , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/genética
6.
Mol Genet Metab ; 114(4): 537-46, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25742969

RESUMO

The association between combined methylmalonic acidemia and homocystinuria of cblC type (cobalamin C defect, cblC) and ocular disease is now well recognized, and is a significant component of morbidity and disability associated with the condition. In this review, through collation of historically reported cases of early- and late-onset cblC and previously unreported cases, we have attempted to characterize the epidemiology, clinical features, and pathomechanisms of individual ocular features of cblC. These data suggest that maculopathy and nystagmus with abnormal vision are extremely common and affect the majority of children with early-onset cblC, usually before school age; strabismus and optic atrophy are also seen at relatively high frequency. The timing of progression of macular disease may coincide with a critical period of postnatal foveal development. Maculopathy and retinal disease may be subclinical and show only partial correlation with the extent of visual deficits, and visual deterioration may be relentlessly progressive in spite of aggressive treatment of biochemical abnormalities. In later-onset forms of the disease, visual loss and ocular complications appear to be infrequent. Finally, we discuss investigational strategies in diagnosing and characterizing eye disease in individuals with cblC, explore possible therapeutic avenues that may attenuate progression and severity of eye disease, and propose a clinical surveillance guideline for monitoring progression of ocular disease in children and adults with cblC.


Assuntos
Oftalmopatias/complicações , Homocistinúria/complicações , Deficiência de Vitamina B 12/congênito , Adulto , Criança , Oftalmopatias/diagnóstico , Feminino , Homocistinúria/genética , Humanos , Masculino , Mutação , Atrofia Óptica/complicações , Atrofia Óptica/diagnóstico , Atrofia Óptica/fisiopatologia , Doenças Retinianas/complicações , Doenças Retinianas/diagnóstico , Doenças Retinianas/fisiopatologia , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/genética
7.
J Neurooncol ; 121(3): 573-81, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25431150

RESUMO

Children with high-grade glioma (HGG) have a poor prognosis compared to those with low-grade glioma (LGG). Adjuvant chemotherapy may be beneficial, but its optimal use remains undetermined. Histology and extent of resection are important prognostic factors. We tested the hypothesis that patients with midline HGG treated on Children's Cancer Group Study (CCG) CCG-945 have a worse prognosis compared to the entire group. Of 172 children eligible for analysis, 60 had midline tumors primarily localized to the thalamus, hypothalamus and basal ganglia. Time-to-progression and death were determined from the date of initial diagnosis, and survival curves were calculated. Univariate analyses were undertaken for extent of resection, chemotherapy regimen, anatomic location, histology, proliferation index, MGMT status and p53 over-expression. For the entire midline tumor group, 5-year PFS and OS were 18.3 ± 4.8 and 25 ± 5.4 %, respectively. Many patients only had a biopsy (43.3 %). The sub-groups with near/total resection and hypothalamic location appeared to have better PFS and OS. However, the effect of tumor histology on OS was significant for children with discordant diagnoses on central pathology review of LGG compared to HGG. Proliferative index (MIB-1 > 36 %), MGMT and p53 over-expression correlated with poor outcomes. Children treated on CCG-945 with midline HGG have a worse prognosis when compared to the entire group. The midline location may directly influence the extent of resection. Central pathology review and entry of patients on clinical trials continue to be priorities to improve outcomes for children with HGG.


Assuntos
Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Glioma/mortalidade , Glioma/patologia , Adolescente , Neoplasias Encefálicas/terapia , Criança , Pré-Escolar , Terapia Combinada , Intervalo Livre de Doença , Feminino , Glioma/terapia , Humanos , Lactente , Recém-Nascido , Estimativa de Kaplan-Meier , Masculino , Gradação de Tumores , Prognóstico
9.
Mol Genet Metab ; 110(3): 241-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23954310

RESUMO

Abnormal neurodevelopment has been widely reported in combined methylmalonic aciduria (MMA) and homocystinuria, cblC type (cblC disease), but neurodevelopmental phenotypes in cblC have not previously been systematically studied. We sought to further characterize developmental neurology in children with molecularly-confirmed cblC. Thirteen children at our center with cblC, born since implementation of expanded newborn screening in New York State, undertook standard-of-care evaluations with a pediatric neurologist and pediatric ophthalmologist. At most recent follow-up (mean age 50 months, range 9-84 months), of twelve children with early-onset cblC, three (25%) had a history of clinical seizures and two (17%) meet criteria for microcephaly. A majority of children had hypotonia and nystagmus. Twelve out of thirteen (92%) underwent neurodevelopmental evaluation (mean age 41 months; range 9-76 months), each child tested with standardized parental interviews and, where possible, age- and disability-appropriate neuropsychological batteries. All patients showed evidence of developmental delay with the exception of one patient with a genotype predictive of attenuated disease and near-normal biochemical parameters. Neurodevelopmental deficits were noted most prominently in motor skills, with relative preservation of socialization and communication skills. Nine children with early-onset cblC underwent magnetic resonance imaging and spectroscopy (MRI/MRS) at mean age of 47 months (range 6-81 months); common abnormalities included callosal thinning, craniocaudally short pons, and increased T2 FLAIR signal in periventricular and periatrial white matter. Our study further characterizes variable neurodevelopmental phenotypes in treated cblC, and provides insights into the etiopathogenesis of disordered neurodevelopment frequently encountered in cblC. Plasma homocysteine and MMA, routinely measured at clinical follow-up, may be poor predictors for neurodevelopmental outcomes. Additional data from large, prospective, multi-center natural history studies are required to more accurately define the role of these metabolites and others, as well as that of other genetic and environmental factors in the etiopathogenesis of the neurologic components of this disorder.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/fisiopatologia , Homocistinúria/diagnóstico , Homocistinúria/fisiopatologia , Fenótipo , Erros Inatos do Metabolismo dos Aminoácidos/dietoterapia , Substituição de Aminoácidos , Proteínas de Transporte/genética , Pré-Escolar , Feminino , Genótipo , Homocistinúria/dietoterapia , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Mutação , Triagem Neonatal , Oxirredutases
11.
Am J Med Genet A ; 155A(10): 2508-11, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21998864

RESUMO

A 28-month-old Peruvian male presented with speech delay and unusual facial features including prominent forehead, anteverted nares, ocular hypertelorism, and low-set and posteriorly rotated ears with a unilateral preauricular pit. The patient had poor speech with no other developmental delays. Height and weight were normal, although closure of the anterior fontanel and bone age were delayed. Head circumference approximated the 95th centile for age. Following normal routine chromosome analysis and subtelomeric FISH, whole genome microarray revealed a novel interstitial duplication at 7p22.1, approximately 1.7 Mb in size, and containing 13 OMIM annotated genes. FISH studies on the propositus and his parents confirmed that the duplication had occurred de novo. This finding represents the smallest interstitial 7p duplication reported to date, and does not include genes previously implicated as candidates for a 7p duplication syndrome. Common phenotypic features of 7p duplication include distinctive facies with hypertelorism,large anterior fontanel, and intellectual disability. Based on the findings in our patient, and those in previously reported cases of 7p duplication, we propose that genes within this duplicated interval may have a role in skeletal maturation,craniofacial development, and speech acquisition.


Assuntos
Anormalidades Múltiplas/genética , Duplicação Cromossômica/genética , Cromossomos Humanos Par 7/genética , Anormalidades Craniofaciais/genética , Anormalidades Múltiplas/patologia , Pré-Escolar , Hibridização Genômica Comparativa , Anormalidades Craniofaciais/patologia , Humanos , Hibridização in Situ Fluorescente , Masculino , Peru
13.
Front Biosci (Landmark Ed) ; 26(8): 387-394, 2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-34455768

RESUMO

Parkinson's disease, in most patients, is possibly caused by natural oxidative stress in dopaminergic neurons, insufficient exercise and galactose induced oxidative stress. Dopamine oxidizes to produce oxygen radicals that damage neurons. Exercise generates lactic acid and myokines that are essential for brain health. Galactose produces oxidative stress in the brain. These factors change with age and lifestyle. It is likely that lifestyle interventions, including daily exercise and much less alcohol and milk consumption, can delay or prevent Parkinson's disease.


Assuntos
Doença de Parkinson , Dopamina , Neurônios Dopaminérgicos , Humanos , Estresse Oxidativo , Doença de Parkinson/etiologia , Espécies Reativas de Oxigênio
14.
Mol Genet Metab ; 99(2): 116-23, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19836982

RESUMO

INTRODUCTION: Combined methylmalonic aciduria and homocystinuria, cobalamin C (cblC) type, is an inherited disorder of vitamin B(12) metabolism caused by mutations in MMACHC. CblC typically presents in the neonatal period with neurological deterioration, failure to thrive, cytopenias, and multisystem pathology including renal and hepatic dysfunction. Rarely, affected individuals present in adulthood with gait ataxia and cognitive decline. Treatment with hydroxocobalamin may ameliorate the clinical features of early-onset disease and prevent clinical late-onset disease. Propionic acidemia (PA), methylmalonic acidemia (MMA), and various disorders of cobalamin metabolism are characterized by elevated propionylcarnitine (C3) on newborn screening (NBS). Distinctions can be made between these disorders with secondary analyte testing. Elevated methionine is already routinely used as a NBS marker for cystathionine beta-synthase deficiency. We propose that low methionine may be useful as a secondary analyte for specific detection of cbl disorders among a larger pool of infants with elevated C3 on NBS. METHODS: Retrospective analysis of dried blood spot (DBS) data in patients with molecularly confirmed cblC disease. RESULTS: Nine out of ten patients with confirmed cblC born in New York between 2005 and 2008 had methionine below 13.4mumol/L on NBS. Elevated C3, elevated C3:C2 ratio, and low methionine were incorporated into a simple screening algorithm that can be used to improve the specificity of newborn screening programs and provide a specific and novel method of distinguishing cblC from other disorders of propionate metabolism prior to recall for confirmatory testing. CONCLUSIONS: It is anticipated that this algorithm will aid in early and specific detection of cobalamin C, D, and F diseases, with no additional expense to NBS laboratories screening for organic acidemias and classical homocystinuria.


Assuntos
Homocistinúria/complicações , Homocistinúria/diagnóstico , Erros Inatos do Metabolismo/complicações , Erros Inatos do Metabolismo/diagnóstico , Metionina , Triagem Neonatal , Vitamina B 12/metabolismo , Algoritmos , Carnitina/análogos & derivados , Carnitina/metabolismo , Demografia , Reações Falso-Positivas , Feminino , Seguimentos , Estudos de Associação Genética , Homocistinúria/genética , Humanos , Recém-Nascido , Masculino , Erros Inatos do Metabolismo/genética , Ácido Metilmalônico/metabolismo , New York , Propionatos/metabolismo , Encaminhamento e Consulta
16.
Evid Based Complement Alternat Med ; 7(2): 219-25, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18955312

RESUMO

Chinese and Chumash traditional medical approaches are similar in terms of disease causation, use of acupuncture or healing touch, plants, spiritual and philosophical approaches. This article provides a brief comparison and discussion of Chinese and Chumash traditional medical practices. A table of 66 plants is presented along with Chinese and Chumash uses of each plant. These uses are compared and contrasted.

17.
Curr Med Chem ; 27(9): 1501-1514, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30027844

RESUMO

Inflammatory states are among the most common and most treated medical conditions. Inflammation comes along with swelling, pain and uneasiness in using the affected area. Inflammation is not always a simple symptom; more often is part of a defensive response of the body to an external threat or is a sign that the damaged tissue has not healed yet and needs to rest. The management of the pain associated with an inflammatory state could be a tricky task. In fact, most remedies simply quench the pain, leaving the inflammatory state unaltered. This review focuses on sesquiterpene lactones, a class of natural compounds, that represents a future promise in the treatment of inflammation. Sesquiterpene lactones are efficient inhibitors of multiple targets of the inflammatory process. Their natural sources are often ancient remedies with relevant traditional uses in folk medicines. This work also aims to elucidate how these compounds may represent the starting material for the development of new anti-inflammatory drugs.


Assuntos
Inflamação , Anti-Inflamatórios , Edema , Humanos , Lactonas , NF-kappa B , Compostos Fitoquímicos , Sesquiterpenos
18.
Childs Nerv Syst ; 25(2): 153-9, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19023578

RESUMO

BACKGROUND: Familial hemophagocytic lymphohistiocytosis (FHLH) is an autosomal recessively inherited multisystem disease characterized by fever, rash, splenomegaly, cytopenias, and variable central nervous system (CNS) manifestations. CASE HISTORY: We report the case of a 3-year-old boy who presented with splenomegaly and normocytic anemia 4 months after returning to the US from a region endemic for Leishmania infection. The child later developed progressive neurological impairment and had radiologic evidence of widespread demyelinating disease. Gene studies showed homozygosity for a mutation at Munc13-4, confirming FHLH type 3. DISCUSSION: The diagnostic uncertainty that accompanies FHLH was compounded by our patient's travel history and CNS disease mimicking acute disseminated encephalomyelitis (ADEM). Diagnostic criteria for hemophagocytic lymphohistiocytosis were not consistently met, despite aggressive disease. CONCLUSIONS: FHLH may present with fulminant demyelinating disease, mimicking ADEM, and without necessarily meeting previously defined clinical and laboratory criteria. We strongly recommend expeditious molecular testing and genetic counseling for FHLH mutations in cases of undiagnosed inflammatory CNS disease in the pediatric population.


Assuntos
Doenças Desmielinizantes/patologia , Linfo-Histiocitose Hemofagocítica/diagnóstico , Proteínas de Membrana/genética , Mutação , Anemia/etiologia , Anemia/patologia , Pré-Escolar , Doenças Desmielinizantes/etiologia , Diagnóstico Diferencial , Humanos , Linfo-Histiocitose Hemofagocítica/complicações , Linfo-Histiocitose Hemofagocítica/genética , Masculino , Esplenomegalia/etiologia , Esplenomegalia/patologia
19.
Mitochondrion ; 44: 58-64, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29307858

RESUMO

Elevations of specific acylcarnitines in blood reflect carboxylase deficiencies, and have utility in newborn screening for life-threatening organic acidemias and other inherited metabolic diseases. In this report, we describe a newly-identified association of biochemical features of multiple carboxylase deficiency in individuals harboring mitochondrial DNA (mtDNA) mutations in MT-ATP6 and in whom organic acidemias and multiple carboxylase deficiencies were excluded. Using retrospective chart review, we identified eleven individuals with abnormally elevated propionylcarnitine (C3) or hydroxyisovalerylcarnitine (C5OH) with mutations in MT-ATP6, most commonly m.8993T>G in high heteroplasmy or homoplasmy. Most patients were ascertained on newborn screening; most had normal enzymatic or molecular genetic testing to exclude biotinidase and holocarboxylase synthetase deficiencies. MT-ATP6 is associated with some cases of Leigh disease; clinical outcomes in our cohort ranged from death from neurodegenerative disease in early childhood to clinically and developmentally normal after several years of follow-up. These cases expand the biochemical phenotype associated with MT-ATP6 mutations, especially m.8993T>G, to include acylcarnitine abnormalities mimicking carboxylase deficiency states. Clinicians should be aware of this association and its implications for newborn screening, and consider mtDNA sequencing in patients exhibiting similar acylcarnitine abnormalities that are biotin-unresponsive and in whom other enzymatic deficiencies have been excluded.


Assuntos
ATPases Mitocondriais Próton-Translocadoras/genética , Deficiência Múltipla de Carboxilase/genética , Deficiência Múltipla de Carboxilase/patologia , Mutação , Adolescente , Carnitina/análogos & derivados , Carnitina/sangue , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Testes Genéticos , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Adulto Jovem
20.
Transl Sci Rare Dis ; 3(3-4): 157-170, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30613471

RESUMO

Organic acidemias and urea cycle disorders are ultra-rare inborn errors of metabolism characterized by episodic acute decompensation, often associated with hyperammonemia, resulting in brain edema and encephalopathy. Retrospective reports and translational studies suggest that N-carbamylglutamate (NCG) may be effective in reducing ammonia levels during acute decompensation in two organic acidemias, propionic and methylmalonic acidemia (PA and MMA), and in two urea cycle disorders, carbamylphosphate synthetase 1 and ornithine transcarbamylase deficiency (CPSD and OTCD). We established the 9-site N-carbamylglutamate Consortium (NCGC) in order to conduct two randomized double-blind, placebo-controlled trials of NCG in acute hyperammonemia of PA, MMA, CPSD and OTCD. Conducting clinical trials is challenging in any disease, but poses unique barriers and risks in the ultra-rare disorders. As the number of clinical trials in orphan diseases increases, evaluating the successes and opportunities for improvement in such trials is essential. We summarize herein the design, methods, experiences, challenges and lessons from the NCGC-conducted trials.

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