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1.
Hum Mutat ; 43(3): 305-315, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35026043

RESUMO

Iron-sulfur cluster proteins are involved in critical functions for gene expression regulation and mitochondrial bioenergetics including the oxidative phosphorylation system. The c.215G>A p.(Arg72Gln) variant in NFS1 has been previously reported to cause infantile mitochondrial complex II and III deficiency. We describe three additional unrelated patients with the same missense variant. Two infants with the same homozygous variant presented with hypotonia, weakness and lactic acidosis, and one patient with compound heterozygous p.(Arg72Gln) and p.(Arg412His) variants presented as a young adult with gastrointestinal symptoms and fatigue. Skeletal muscle biopsy from patients 1 and 3 showed abnormal mitochondrial morphology, and functional analyses demonstrated decreased activity in respiratory chain complex II and variably in complexes I and III. We found decreased mitochondrial and cytosolic aconitase activities but only mildly affected lipoylation of pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase enzymes. Our studies expand the phenotypic spectrum and provide further evidence for the pathogenicity and functional sequelae of NFS1-related disorders with disturbances in both mitochondrial and cytosolic iron-sulfur cluster containing enzymes.


Assuntos
Proteínas Ferro-Enxofre , Ferro , Liases de Carbono-Enxofre/genética , Liases de Carbono-Enxofre/metabolismo , Complexo I de Transporte de Elétrons/metabolismo , Humanos , Ferro/metabolismo , Proteínas Ferro-Enxofre/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Enxofre/metabolismo , Adulto Jovem
2.
Child Neurol Open ; 8: 2329048X211030723, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34395718

RESUMO

We present a case of a young child with a rare metabolic disorder whose clinical presentation resembled that of autoimmune myasthenia gravis. The differential diagnosis was expanded when autoantibody testing was negative and the patient did not respond to standard immunomodulatory therapies. Rapid whole genome sequencing identified 2 rare variants of uncertain significance in the SLC52A3 gene shown to be in compound heterozygous state after parental testing. Biallelic mutations in SLC52A3 are associated with Riboflavin Transporter Deficiency, which in its untreated form, results in progressive neurodegeneration and death. Supplementation with oral riboflavin has been shown to limit disease progression and improve symptoms in some patients. When the diagnosis is suspected, patients should be started on supplementation immediately while awaiting results from genetic studies.

3.
Ann Clin Transl Neurol ; 8(1): 284-287, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33249780

RESUMO

Refractory epilepsy and encephalopathy are frequently encountered in patients with inborn errors of metabolism. We report a case of an 8-year-old girl with history of developmental delay, autism and intractable epilepsy that was found to have a pathogenic variant in CAD. We briefly review the biochemical pathway of CAD and the preclinical and clinical studies that suggest uridine supplementation can rescue the CAD deficiency phenotypes. Our case demonstrates a relatively late-onset case of refractory epilepsy with a rapid response to treatment using the uridine pro-drug triacetyluridine (TAU), the FDA-approved treatment for hereditary orotic aciduria.


Assuntos
Acetatos/uso terapêutico , Aspartato Carbamoiltransferase/genética , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/genética , Di-Hidro-Orotase/genética , Epilepsia Generalizada/tratamento farmacológico , Epilepsia Generalizada/genética , Uridina/análogos & derivados , Criança , Feminino , Humanos , Mutação de Sentido Incorreto , Uridina/uso terapêutico
4.
Dev Neurosci ; 31(1-2): 7-22, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19372683

RESUMO

Defects in the development of the brain have a profound impact on mature brain functions and underlying psychopathology. Classical neurotransmitters and neuromodulators, such as dopamine, serotonin, norepinephrine, acetylcholine, glutamate and GABA, have pleiotropic effects during brain development. In other words, these molecules produce multiple diverse effects to serve as regulators of distinct cellular functions at different times in neurodevelopment. These systems are impacted upon by abuse of a variety of illicit drugs, neurotherapeutics and environmental contaminants. In this review, we describe the impact of drugs and chemicals on brain formation and function in animal models and in human populations, highlighting sensitive periods and effects that may not emerge until later in life.


Assuntos
Aminas Biogênicas/metabolismo , Química Encefálica/fisiologia , Encéfalo/crescimento & desenvolvimento , Transtornos Relacionados ao Uso de Substâncias/complicações , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Adulto , Transtornos Relacionados ao Uso de Anfetaminas/complicações , Transtornos Relacionados ao Uso de Anfetaminas/metabolismo , Animais , Comportamento/efeitos dos fármacos , Criança , Desenvolvimento Infantil , Transtornos Relacionados ao Uso de Cocaína/complicações , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Poluentes Ambientais/efeitos adversos , Feminino , Humanos , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Gravidez , Psicotrópicos/efeitos adversos , Toxinas Biológicas/toxicidade
5.
Front Behav Neurosci ; 6: 29, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22723772

RESUMO

Many neurotransmitters, hormones, and sensory stimuli elicit their cellular responses through the targeted activation of receptors coupled to the G(αq) family of heterotrimeric G proteins. Nevertheless, we still understand little about the consequences of loss of this signaling activity on brain function. We therefore examined the effects of genetic inactivation of Gnaq, the gene that encode for G(αq), on responsiveness in a battery of behavioral tests in order to assess the contribution of G(αq) signaling capacity in the brain circuits mediating expression of affective behaviors (anxiety and behavioral despair), spatial working memory, and locomotor output (coordination, strength, spontaneous activity, and drug-induced responses). First, we replicated and extended findings showing clear motor deficits in G(αq) knockout mice as assessed on an accelerating rotarod and the inverted screen test. We then assessed the contribution of the basal ganglia motor loops to these impairments, using open field testing and analysis of drug-induced locomotor responses to the psychostimulant cocaine, the benzazepine D(1) receptor agonists SKF83822 and SKF83959, and the NMDA receptor antagonist MK-801. We observed significant increases in drug-induced locomotor activity in G(αq) knockout mice from the dopaminergic agonists but not MK-801, indicating that basal ganglia locomotor circuitry is largely intact in the absence of G(αq). Additionally, we observed normal phenotypes in both the elevated zero maze and the forced swim test indicating that anxiety and depression-related circuitry appears to be largely intact after loss of Gnaq expression. Lastly, use of the Y-maze revealed spatial memory deficits in G(αq) knockout mice, indicating that receptors signaling through G(αq) are necessary in these circuits for proficiency in this task.

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