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1.
Front Genet ; 15: 1355962, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38425716

RESUMO

Classic galactosemia (CG, OMIM #230400, ORPHA: 79,239) is a hereditary disorder of galactose metabolism that, despite treatment with galactose restriction, affects brain function in 85% of the patients. Problems with cognitive function, neuropsychological/social emotional difficulties, neurological symptoms, and abnormalities in neuroimaging and electrophysiological assessments are frequently reported in this group of patients, with an enormous individual variability. In this review, we describe the role of impaired galactose metabolism on brain dysfunction based on state of the art knowledge. Several proposed disease mechanisms are discussed, as well as the time of damage and potential treatment options. Furthermore, we combine data from longitudinal, cross-sectional and retrospective studies with the observations of specialist teams treating this disease to depict the brain disease course over time. Based on current data and insights, the majority of patients do not exhibit cognitive decline. A subset of patients, often with early onset cerebral and cerebellar volume loss, can nevertheless experience neurological worsening. While a large number of patients with CG suffer from anxiety and depression, the increased complaints about memory loss, anxiety and depression at an older age are likely multifactorial in origin.

2.
JCI Insight ; 9(4)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38271099

RESUMO

A distinct adipose tissue distribution pattern was observed in patients with methylmalonyl-CoA mutase deficiency, an inborn error of branched-chain amino acid (BCAA) metabolism, characterized by centripetal obesity with proximal upper and lower extremity fat deposition and paucity of visceral fat, that resembles familial multiple lipomatosis syndrome. To explore brown and white fat physiology in methylmalonic acidemia (MMA), body composition, adipokines, and inflammatory markers were assessed in 46 patients with MMA and 99 matched controls. Fibroblast growth factor 21 levels were associated with acyl-CoA accretion, aberrant methylmalonylation in adipose tissue, and an attenuated inflammatory cytokine profile. In parallel, brown and white fat were examined in a liver-specific transgenic MMA mouse model (Mmut-/- TgINS-Alb-Mmut). The MMA mice exhibited abnormal nonshivering thermogenesis with whitened brown fat and had an ineffective transcriptional response to cold stress. Treatment of the MMA mice with bezafibrates led to clinical improvement with beiging of subcutaneous fat depots, which resembled the distribution seen in the patients. These studies defined what we believe to be a novel lipodystrophy phenotype in patients with defects in the terminal steps of BCAA oxidation and demonstrated that beiging of subcutaneous adipose tissue in MMA could readily be induced with small molecules.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos , Fatores de Crescimento de Fibroblastos , Lipodistrofia , Animais , Humanos , Camundongos , Erros Inatos do Metabolismo dos Aminoácidos/complicações , Erros Inatos do Metabolismo dos Aminoácidos/genética , Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Camundongos Transgênicos
3.
Mol Genet Metab ; 140(3): 107693, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37716025

RESUMO

Newborn screening (NBS) began a revolution in the management of biochemical genetic diseases, greatly increasing the number of patients for whom dietary therapy would be beneficial in preventing complications in phenylketonuria as well as in a few similar disorders. The advent of next generation sequencing and expansion of NBS have markedly increased the number of biochemical genetic diseases as well as the number of patients identified each year. With the avalanche of new and proposed therapies, a second wave of options for the treatment of biochemical genetic disorders has emerged. These therapies range from simple substrate reduction to enzyme replacement, and now ex vivo gene therapy with autologous cell transplantation. In some instances, it may be optimal to introduce nucleic acid therapy during the prenatal period to avoid fetopathy. However, as with any new therapy, complications may occur. It is important for physicians and other caregivers, along with ethicists, to determine what new therapies might be beneficial to the patient, and which therapies have to be avoided for those individuals who have less severe problems and for which standard treatments are available. The purpose of this review is to discuss the "Standard" treatment plans that have been in place for many years and to identify the newest and upcoming therapies, to assist the physician and other healthcare workers in making the right decisions regarding the initiation of both the "Standard" and new therapies. We have utilized several diseases to illustrate the applications of these different modalities and discussed for which disorders they may be suitable. The future is bright, but optimal care of the patient, including and especially the newborn infant, requires a deep knowledge of the disease process and careful consideration of the necessary treatment plan, not just based on the different genetic defects but also with regards to different variants within a gene itself.


Assuntos
Erros Inatos do Metabolismo , Fenilcetonúrias , Recém-Nascido , Lactente , Gravidez , Feminino , Humanos , Erros Inatos do Metabolismo/genética , Erros Inatos do Metabolismo/terapia , Erros Inatos do Metabolismo/diagnóstico , Triagem Neonatal , Fenilcetonúrias/genética , Fenilcetonúrias/terapia , Biologia Molecular , Sequenciamento de Nucleotídeos em Larga Escala
4.
Hum Reprod Update ; 29(2): 246-258, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36512573

RESUMO

BACKGROUND: Hypergonadotropic hypogonadism is a burdensome complication of classic galactosemia (CG), an inborn error of galactose metabolism that invariably affects female patients. Since its recognition in 1979, data have become available regarding the clinical spectrum, and the impact on fertility. Many women have been counseled for infertility and the majority never try to conceive, yet spontaneous pregnancies can occur. Onset and mechanism of damage have not been elucidated, yet new insights at the molecular level are becoming available that might greatly benefit our understanding. Fertility preservation options have expanded, and treatments to mitigate this complication either by directly rescuing the metabolic defect or by influencing the cascade of events are being explored. OBJECTIVE AND RATIONALE: The aims are to review: the clinical picture and the need to revisit the counseling paradigm; insights into the onset and mechanism of damage at the molecular level; and current treatments to mitigate ovarian damage. SEARCH METHODS: In addition to the work on this topic by the authors, the PubMed database has been used to search for peer-reviewed articles and reviews using the following terms: 'classic galactosemia', 'gonadal damage', 'primary ovarian insufficiency', 'fertility', 'animal models' and 'fertility preservation' in combination with other keywords related to the subject area. All relevant publications until August 2022 have been critically evaluated and reviewed. OUTCOMES: A diagnosis of premature ovarian insufficiency (POI) results in a significant psychological burden with a high incidence of depression and anxiety that urges adequate counseling at an early stage, appropriate treatment and timely discussion of fertility preservation options. The cause of POI in CG is unknown, but evidence exists of dysregulation in pathways crucial for folliculogenesis such as phosphatidylinositol 3-kinase/protein kinase B, inositol pathway, mitogen-activated protein kinase, insulin-like growth factor-1 and transforming growth factor-beta signaling. Recent findings from the GalT gene-trapped (GalTKO) mouse model suggest that early molecular changes in 1-month-old ovaries elicit an accelerated growth activation and burnout of primordial follicles, resembling the progressive ovarian failure seen in patients. Although data on safety and efficacy outcomes are still limited, ovarian tissue cryopreservation can be a fertility preservation option. Treatments to overcome the genetic defect, for example nucleic acid therapy such as mRNA or gene therapy, or that influence the cascade of events are being explored at the (pre-)clinical level. WIDER IMPLICATIONS: Elucidation of the molecular pathways underlying POI of any origin can greatly advance our insight into the pathogenesis and open new treatment avenues. Alterations in these molecular pathways might serve as markers of disease progression and efficiency of new treatment options.


Assuntos
Galactosemias , Hipogonadismo , Infertilidade , Gravidez , Animais , Camundongos , Feminino , Humanos , Galactosemias/diagnóstico , Galactosemias/genética , Galactosemias/metabolismo , Fertilidade/fisiologia , Infertilidade/metabolismo , Ovário/fisiologia , Hipogonadismo/complicações
5.
Orphanet J Rare Dis ; 17(1): 331, 2022 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-36056436

RESUMO

BACKGROUND: Galactose epimerase (GALE) deficiency is a rare hereditary disorder of galactose metabolism with only a few cases described in the literature. This study aims to present the data of patients with GALE deficiency from different countries included through the Galactosemia Network to further expand the existing knowledge and review the current diagnostic strategy, treatment and follow-up of this not well characterized entity. METHODS: Observational study collecting medical data from December 2014 to April 2022 of 22 not previously reported patients from 14 centers in 9 countries. Patients were classified as generalized or non-generalized based on their genotype, enzyme activities in different tissues and/or clinical picture and professional judgment of the treating physician. RESULTS: In total 6 patients were classified as generalized and 16 as non-generalized. In the generalized group, acute neonatal illness was reported in 3, cognitive and developmental delays were present in 5 and hearing problems were reported in 3. Four generalized patients were homozygous for the genetic variant NM_001008216.2:c.280G > A (p.Val94Met). In the non-generalized group, no clearly related symptoms were found. Ten novel genetic variants were reported in this study population. CONCLUSION: The phenotypic spectrum of GALE deficiency ranges from asymptomatic to severe. The generalized patients have a phenotype that is in line with the 9 described cases in the literature and prescribing dietary interventions is the cornerstone for treatment. In the non-generalized group, treatment advice is more difficult. To be able to offer proper counseling, in addition to red blood cell enzyme activity, genetic studies, transferrin glycoform analysis and enzymatic measurements in fibroblasts are recommended. Due to lack of facilities, additional enzymatic testing is not common practice in many centers nor a tailored long-term follow-up is performed.


Assuntos
Galactosemias , Galactosemias/genética , Galactosemias/metabolismo , Genótipo , Homozigoto , Humanos , Sistema de Registros , UDPglucose 4-Epimerase/genética , UDPglucose 4-Epimerase/metabolismo
6.
J Inherit Metab Dis ; 45(6): 1106-1117, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36093991

RESUMO

Patients with galactosemia who carry the S135L (c.404C > T) variant of galactose-1-P uridylyltransferase (GALT), documented to encode low-level residual GALT activity, have been under-represented in most prior studies of outcomes in Type 1 galactosemia. What is known about the acute and long-term outcomes of these patients, therefore, is based on very limited data. Here, we present a study comparing acute and long-term outcomes of 12 patients homozygous for S135L, 25 patients compound heterozygous for S135L, and 105 patients homozygous for two GALT-null (G) alleles. This is the largest cohort of S135L patients characterized to date. Acute disease following milk exposure in the newborn period was common among patients in all 3 comparison groups in our study, as were long-term complications in the domains of speech, cognition, and motor outcomes. In contrast, while at least 80% of both GALT-null and S135L compound heterozygous girls and women showed evidence of an adverse ovarian outcome, prevalence was only 25% among S135L homozygotes. Further, all young women in this study with even one copy of S135L achieved spontaneous menarche; this is true for only about 33% of women with classic galactosemia. Overall, we observed that while most long-term outcomes trended milder among groups of patients with even one copy of S135L, many individual patients, either homozygous or compound heterozygous for S135L, nonetheless experienced long-term outcomes that were not mild. This was true despite detection by newborn screening and both early and life-long dietary restriction of galactose. This information should empower more evidence-based counseling for galactosemia patients with S135L.


Assuntos
Galactosemias , Feminino , Humanos , Recém-Nascido , Alelos , Galactose , Galactosemias/genética , Galactosemias/diagnóstico , Homozigoto , UTP-Hexose-1-Fosfato Uridililtransferase/genética
7.
Mol Genet Metab ; 137(1-2): 33-39, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35882174

RESUMO

Despite many decades of research involving both human subjects and model systems, the underlying pathophysiology of long-term complications in classic galactosemia (CG) remains poorly understood. In this review, intended for those already familiar with galactosemia, we focus on the big questions relating to outcomes, mechanism, and markers, drawing on relevant literature where available, attempting to navigate inconsistencies where they appear, and acknowledging gaps in knowledge where they persist.


Assuntos
Galactosemias , Humanos , Galactosemias/complicações , Galactosemias/genética , Modelos Biológicos , UTP-Hexose-1-Fosfato Uridililtransferase
8.
Eur J Hum Genet ; 30(9): 1083-1087, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35768521

RESUMO

Pathogenic variants in the SRCAP (SNF2-related CREBBP activator protein) gene, which encodes a chromatin-remodeling ATPase, cause neurodevelopmental disorders including Floating Harbor syndrome (FLHS). Here, we report the discovery of a de novo transposon insertion in SRCAP exon 13 from trio genome sequencing in a 28-year-old female with failure to thrive, developmental delay, mood disorder and seizure disorder. The insertion was a full-length (~2.8 kb), antisense-oriented SVA insertion relative to the SRCAP transcript, bearing a 5' transduction and hallmarks of target-primed reverse transcription. The 20-bp 5' transduction allowed us to trace the source SVA element to an intron of a long non-coding RNA on chromosome 12, which is highly expressed in testis. RNA sequencing and qRT-PCR confirmed significant depletion of SRCAP expression and low-level exon skipping in the proband. This case highlights a novel disease-causing structural variant and the importance of transposon analysis in a clinical diagnostic setting.


Assuntos
Anormalidades Múltiplas , Anormalidades Craniofaciais , Comunicação Interventricular , Transtornos do Neurodesenvolvimento , Anormalidades Múltiplas/genética , Adenosina Trifosfatases/genética , Adulto , Anormalidades Craniofaciais/genética , Éxons , Feminino , Comunicação Interventricular/genética , Humanos , Masculino , Transtornos do Neurodesenvolvimento/diagnóstico , Transtornos do Neurodesenvolvimento/genética
9.
JIMD Rep ; 63(2): 131-136, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35281664

RESUMO

We report two patients with PMM2-CDG who developed end stage renal disease (ESRD). Renal abnormalities of clinical significance have only been reported in about 6% of patients with PMM2-CDG and have rarely been reported as the cause of death. Given the recurrent episodes of acute kidney injury associated with hospital admissions and the accelerated development of ESRD thereafter in our two patients, we recommend proactively involving Nephrology early in the care of these patients.

10.
Genet Med ; 24(4): 839-850, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35027292

RESUMO

PURPOSE: This study aimed to evaluate genetic contributions to sudden unexpected death in pediatrics (SUDP). METHODS: We phenotyped and performed exome sequencing for 352 SUDP cases. We analyzed variants in 294 "SUDP genes" with mechanisms plausibly related to sudden death. In a subset of 73 cases with parental data (trios), we performed exome-wide analyses and conducted cohort-wide burden analyses. RESULTS: In total, we identified likely contributory variants in 37 of 352 probands (11%). Analysis of SUDP genes identified pathogenic/likely pathogenic variants in 12 of 352 cases (SCN1A, DEPDC5 [2], GABRG2, SCN5A [2], TTN [2], MYBPC3, PLN, TNNI3, and PDHA1) and variants of unknown significance-favor-pathogenic in 17 of 352 cases. Exome-wide analyses of the 73 cases with family data additionally identified 4 de novo pathogenic/likely pathogenic variants (SCN1A [2], ANKRD1, and BRPF1) and 4 de novo variants of unknown significance-favor-pathogenic. Comparing cases with controls, we demonstrated an excess burden of rare damaging SUDP gene variants (odds ratio, 2.94; 95% confidence interval, 2.37-4.21) and of exome-wide de novo variants in the subset of 73 with trio data (odds ratio, 3.13; 95% confidence interval, 1.91-5.16). CONCLUSION: We provide strong evidence for a role of genetic factors in SUDP, involving both candidate genes and novel genes for SUDP and expanding phenotypes of disease genes not previously associated with sudden death.


Assuntos
Morte Súbita , Pediatria , Proteínas Adaptadoras de Transdução de Sinal , Criança , Pré-Escolar , Proteínas de Ligação a DNA , Exoma/genética , Humanos , Lactente , Recém-Nascido , Fenótipo , Sequenciamento do Exoma
11.
JIMD Rep ; 62(1): 30-34, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34765395

RESUMO

Lesch-Nyhan syndrome is an x-linked genetic disorder of purine metabolism that results in the overproduction of uric acid and neurologic deficits manifesting as intellectual disability, dystonia, other movement disorders and self-mutilation. We describe a 12-year-old patient with a history of Lesch-Nyhan syndrome, G6PD deficiency and central diabetes insipidus and multiple admissions for fever, acute kidney injury and transaminitis in the setting of rhabdomyolysis. The patient's temperature dysregulation and dysautonomia is likely attributable to abnormal neurotransmitter release, particularly that of dopamine, in the central nervous system. Our patient presented similarly to that of a patient with neuroleptic malignant syndrome (NMS), with symptoms including altered mental status, fever, dysautonomia and renal failure, and laboratory findings including elevated serum creatinine kinase, leukocytosis, transaminitis, hypernatremia and metabolic acidosis. Similar to NMS, disruption of dopamine neurotransmission results in dysregulated sympathetic activity and hyperthermia.

12.
Mol Genet Metab ; 134(1-2): 132-138, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34391645

RESUMO

Duarte galactosemia is not classic galactosemia, but rather an example of biochemical variant galactosemia that results in approximately 25% residual activity of galactose-1-phosphate uridylyltransferase (GALT) enzyme. In contrast, classic galactosemia is associated with complete or near complete absence of GALT activity. While infants with classic galactosemia are placed on galactose-restricted diets to prevent the acute and long-term manifestations of their metabolic disorder, while individuals with Duarte variant galactosemia (Duarte-2 galactosemia) do not require diet therapy. The long-term complications that are seen in classic galactosemia such as cerebellar ataxia, and hypergonadotropic hypogonadism do not occur in Duarte-2 galactosemia. While Duarte galactosemia does not appear to be a metabolic disease, it may have an impact on early neurodevelopmental outcomes. This study examined developmental outcomes and the need for special services in individuals with Duarte-2 galactosemia in comparison to individuals with classic galactosemia. We performed a medical record review of individuals with GALT deficiency who were evaluated at Boston Children's Hospital and enrolled in our study of outcomes in galactosemia. This included 95 participants, 21 with Duarte-2 galactosemia and 73 with classic galactosemia. Duarte-2 participants had developmental test scores within the average range. However, 42% of subjects with Duarte-2 galactosemia had participated in early intervention and/or special education and 32% received speech therapy. Their pattern of strengths and weaknesses in cognitive/language/motor domains was similar to that noted in participants with classic galactosemia, albeit to a milder degree. The data indicate that in children with Duarte-2 variant galactosemia, the cognitive/language and motor skills were within normal limits with their cognitive/language skills developing earlier than their motor skills during their first year of life. A history of diet treatment was not related to the use of special services. These results suggest that Duarte-2 galactosemia increases the risk for early mild developmental delays irrespective of treatment history, which resolves over time, and highlights the need to further assess neurodevelopment in early infancy, in Duarte-2 galactosemia. As Duarte-2 galactosemia is not a bona fide biochemical genetic disease, we hypothesize that elements in the genomic space that include the GALT gene are responsible for a transient delay in language-related motor skills during early infancy.


Assuntos
Alelos , Desenvolvimento Infantil , Galactosemias/classificação , Galactosemias/genética , Variação Genética , Pré-Escolar , Feminino , Galactosemias/fisiopatologia , Genótipo , Humanos , Lactente , Masculino , Transtornos do Neurodesenvolvimento/etiologia , Transtornos do Neurodesenvolvimento/genética , Fenótipo , Estudos Retrospectivos , UTP-Hexose-1-Fosfato Uridililtransferase/genética
13.
JIMD Rep ; 59(1): 104-109, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33977035

RESUMO

Galactokinase deficiency is an inborn error of carbohydrate metabolism due to a block in the formation of galactose-1-phosphate from galactose. Although the association of galactokinase deficiency with formation of cataracts is well established, the extent of the clinical phenotype is still under investigation. We describe a 6-year-old female who was diagnosed with galactokinase deficiency due to cataract formation when she was 10 months of age and initially started on galactose-restricted diet at that time for 5 months. She developed gait abnormality at 4 years of age. Breath tests via measurement of 13C isotope in exhaled carbon dioxide following 13C-labeled galactose administration at carbon-1 and carbon-2 positions revealed oxidation rates within the normal range. The results in this patient strikingly contrast with the results of another patient with GALK1 deficiency that underwent breath testing with [1-14C]-galactose and [2-14C]-galactose. Extension of in vivo breath tests to other galactokinase patients is needed to better understand the pathophysiology of this disease.

14.
Mol Genet Metab Rep ; 27: 100742, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33763331

RESUMO

Adult-onset non-cirrhotic hyperammonemia (NCH) is a rare, but often fatal condition that can result in both reversible and irreversible neurological defects. Here we present five cases of adult-onset non-cirrhotic hyperammonemia wherein brain magnetic resonance spectroscopy (MRS) scans for cerebral glutamine (Gln) and myo-inositol (mI) levels helped guide clinical management. Specifically, we demonstrate that when combined with traditional brain magnetic resonance imaging (MRI) scans, cerebral Gln and mI MRS can help disentangle the reversible from irreversible neurological defects associated with hyperammonemic crisis. Specifically, we demonstrate that whereas an elevated brain MRS Gln level is associated with reversible neurological defects, markedly low mI levels are associated with a risk for irreversible neurological defects such as central pontine myelinolysis. Overall, our findings indicate the utility of brain MRS in guiding clinical care and prognosis in patients with adult-onset non-cirrhotic hyperammonemia.

16.
Genet Med ; 23(1): 202-210, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32807972

RESUMO

PURPOSE: Galactokinase (GALK1) deficiency is a rare hereditary galactose metabolism disorder. Beyond cataract, the phenotypic spectrum is questionable. Data from affected patients included in the Galactosemias Network registry were collected to better characterize the phenotype. METHODS: Observational study collecting medical data of 53 not previously reported GALK1 deficient patients from 17 centers in 11 countries from December 2014 to April 2020. RESULTS: Neonatal or childhood cataract was reported in 15 and 4 patients respectively. The occurrence of neonatal hypoglycemia and infection were comparable with the general population, whereas bleeding diathesis (8.1% versus 2.17-5.9%) and encephalopathy (3.9% versus 0.3%) were reported more often. Elevated transaminases were seen in 25.5%. Cognitive delay was reported in 5 patients. Urinary galactitol was elevated in all patients at diagnosis; five showed unexpected Gal-1-P increase. Most patients showed enzyme activities ≤1%. Eleven different genotypes were described, including six unpublished variants. The majority was homozygous for NM_000154.1:c.82C>A (p.Pro28Thr). Thirty-five patients were diagnosed following newborn screening, which was clearly beneficial. CONCLUSION: The phenotype of GALK1 deficiency may include neonatal elevation of transaminases, bleeding diathesis, and encephalopathy in addition to cataract. Potential complications beyond the neonatal period are not systematically surveyed and a better delineation is needed.


Assuntos
Catarata , Galactoquinase/deficiência , Galactosemias , Galactoquinase/genética , Galactosemias/epidemiologia , Galactosemias/genética , Homozigoto , Humanos , Recém-Nascido , Sistema de Registros
17.
Am J Med Genet A ; 185(1): 203-207, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33037779

RESUMO

Inherited optic neuropathies (IONs) are neurodegenerative disorders characterized by optic atrophy with or without extraocular manifestations. Optic atrophy-10 (OPA10) is an autosomal recessive ION recently reported to be caused by mutations in RTN4IP1, which encodes reticulon 4 interacting protein 1 (RTN4IP1), a mitochondrial ubiquinol oxydo-reductase. Here we report novel compound heterozygous mutations in RTN4IP1 in a male proband with developmental delay, epilepsy, optic atrophy, ataxia, and choreoathetosis. Workup was notable for transiently elevated lactate and lactate-to-pyruvate ratio, brain magnetic resonance imaging with optic atrophy and T2 signal abnormalities, and a nondiagnostic initial genetic workup, including chromosomal microarray and mitochondrial panel testing. Exome sequencing identified a paternally inherited missense variant (c.263T>G, p.Val88Gly) predicted to be deleterious and a maternally inherited deletion encompassing RTN4IP1. To our knowledge, this is the first report of a non-single nucleotide pathogenic variant associated with OPA10. This case highlights the expanding phenotypic spectrum of OPA10, the association between "syndromic" cases and severe RTN4IP1 mutations, and the importance of nonbiased genetic testing, such as ES, to analyze multiple genes and variants types, in patients suspected of having genetic disease.


Assuntos
Proteínas de Transporte/genética , Deficiências do Desenvolvimento/genética , Epilepsia/genética , Proteínas Mitocondriais/genética , Atrofia Óptica/genética , Ataxia/diagnóstico por imagem , Ataxia/genética , Ataxia/patologia , Proteínas de Transporte/ultraestrutura , Pré-Escolar , Deficiências do Desenvolvimento/diagnóstico por imagem , Deficiências do Desenvolvimento/patologia , Epilepsia/diagnóstico por imagem , Epilepsia/patologia , Exoma/genética , Feminino , Predisposição Genética para Doença , Testes Genéticos/métodos , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Proteínas Mitocondriais/ultraestrutura , Mutação/genética , Atrofia Óptica/diagnóstico por imagem , Atrofia Óptica/patologia , Linhagem , Conformação Proteica , Relação Estrutura-Atividade , Sequenciamento do Exoma
18.
Mol Genet Metab ; 131(1-2): 147-154, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32828637

RESUMO

Inborn errors of metabolism (IEM) involving the non-oxidative pentose phosphate pathway (PPP) include the two relatively rare conditions, transketolase deficiency and transaldolase deficiency, both of which can be difficult to diagnosis given their non-specific clinical presentations. Current biochemical testing approaches require an index of suspicion to consider targeted urine polyol testing. To determine whether a broad-spectrum biochemical test could accurately identify a specific metabolic pattern defining IEMs of the non-oxidative PPP, we employed the use of clinical metabolomic profiling as an unbiased novel approach to diagnosis. Subjects with molecularly confirmed IEMs of the PPP were included in this study. Targeted quantitative analysis of polyols in urine and plasma samples was accomplished with chromatography and mass spectrometry. Semi-quantitative unbiased metabolomic analysis of urine and plasma samples was achieved by assessing small molecules via liquid chromatography and high-resolution mass spectrometry. Results from untargeted and targeted analyses were then compared and analyzed for diagnostic acuity. Two siblings with transketolase (TKT) deficiency and three unrelated individuals with transaldolase (TALDO) deficiency were identified for inclusion in the study. For both IEMs, targeted polyol testing and untargeted metabolomic testing on urine and/or plasma samples identified typical perturbations of the respective disorder. Additionally, untargeted metabolomic testing revealed elevations in other PPP metabolites not typically measured with targeted polyol testing, including ribonate, ribose, and erythronate for TKT deficiency and ribonate, erythronate, and sedoheptulose 7-phosphate in TALDO deficiency. Non-PPP alternations were also noted involving tryptophan, purine, and pyrimidine metabolism for both TKT and TALDO deficient patients. Targeted polyol testing and untargeted metabolomic testing methods were both able to identify specific biochemical patterns indicative of TKT and TALDO deficiency in both plasma and urine samples. In addition, untargeted metabolomics was able to identify novel biomarkers, thereby expanding the current knowledge of both conditions and providing further insight into potential underlying pathophysiological mechanisms. Furthermore, untargeted metabolomic testing offers the advantage of having a single effective biochemical screening test for identification of rare IEMs, like TKT and TALDO deficiencies, that may otherwise go undiagnosed due to their generally non-specific clinical presentations.


Assuntos
Erros Inatos do Metabolismo dos Carboidratos/genética , Erros Inatos do Metabolismo/genética , Transaldolase/deficiência , Transaldolase/genética , Transcetolase/genética , Adulto , Biomarcadores/sangue , Erros Inatos do Metabolismo dos Carboidratos/sangue , Erros Inatos do Metabolismo dos Carboidratos/metabolismo , Erros Inatos do Metabolismo dos Carboidratos/patologia , Criança , Pré-Escolar , Cromatografia Líquida , Feminino , Humanos , Lactente , Masculino , Espectrometria de Massas , Erros Inatos do Metabolismo/sangue , Erros Inatos do Metabolismo/metabolismo , Erros Inatos do Metabolismo/patologia , Metabolômica , Via de Pentose Fosfato/genética , Transaldolase/sangue , Transaldolase/metabolismo , Transcetolase/sangue , Transcetolase/deficiência , Adulto Jovem
19.
J Inherit Metab Dis ; 43(6): 1165-1172, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32713002

RESUMO

Adult-onset noncirrhotic hyperammonemia (NCH) is poorly understood and has a high morbidity and mortality. To elucidate the etiology and management of NCH, we performed a retrospective analysis of 23 adults (median age 51) with NCH treated between 2014 and 2020 at two academic medical centers. Hyperammonemia was diagnosed in all cases during the evaluation of altered mental status, with 22% presenting with seizures. Peak ammonia levels were >200 µmol/L in 70% of cases. Defects in ammonia metabolism were assessed using urea cycle biochemical testing, germline genetic testing, and testing for urease-producing infectious agents. Ammonia metabolism defects in these cases appear attributable to four major sources: (a) infection with urease-producing organism (n = 5); (b) previously undiagnosed inborn errors of metabolism (IEMs) (n = 4); (c) clinical exposures causing acquired urea cycle dysfunction (n = 6); and (d) unexplained acquired urea cycle dysfunction (uaUCD) (n = 8), as evidenced by biochemical signatures of urea cycle dysfunction without a genetic or clinical exposure. Severe protein malnutrition appeared to be a reversible risk factor for uaUCD. Overall, 13% of our cohort died prior to resolution of hyperammonemia, 26% died after hyperammonemia resolution, 57% survived after having reversible neurological changes, and 4% survived with irreversible neurological changes. Renal replacement therapy for ammonia clearance was often utilized for patients with an ammonia level above 250 µmol/L and patients were frequently empirically treated with antibiotics targeting urea-splitting organisms. Our study demonstrates that acquired urea cycle dysfunction, IEMs and urease-producing infections are major sources of adult-onset NCH and highlights successful management strategies for adult-onset NCH.


Assuntos
Hiperamonemia/diagnóstico , Distúrbios Congênitos do Ciclo da Ureia/diagnóstico , Adulto , Idade de Início , Idoso , Amônia/sangue , Feminino , Humanos , Hiperamonemia/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Convulsões/complicações , Análise de Sobrevida , Ureia/metabolismo , Adulto Jovem
20.
JIMD Rep ; 54(1): 3-8, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32685343

RESUMO

Cardiomyopathy is a frequent complication of propionic acidemia (PA). It is often fatal, and its occurrence is largely independent of classic metabolic treatment modalities. Liver transplantation (LT) is a treatment option for severe PA as the liver plays a vital role in metabolism of the precursors that accumulate in patients with PA. LT in PA is now considered to be a long-lasting and valid treatment to prevent cardiac disease. The subject of this report had severe cardiomyopathy that largely disappeared prior to undergoing a LT. Three years following the transplant, there was recurrence of cardiomyopathy following a surgery that was complicated with a postoperative aspiration pneumonia. On his last hospital admission, he was presented with pulmonary edema and heart failure. He continued with episodes of intractable hypotension, despite maximum inotropic and diuretic support. He died following redirection of care. We conclude that lethal cardiomyopathy may develop several years after successful LT in patients with PA.

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