SYNGAP1 and Methylenetetrahydrofolate in Cerebrospinal Fluid: Cognitive Development after Oral Folate (5-Methyltetrahydrofolate) Supplementation in a 5-Year-Old Girl

2021 ◽  
Author(s):  
Valentin Hess ◽  
Justine Miguel ◽  
Chrystèle Bonnemains ◽  
Claire Bilbault
Keyword(s):  
Cerebrospinal Fluid ◽  
Methylenetetrahydrofolate Reductase ◽  
Genetic Disorders ◽  
Autism Spectrum ◽  
Epileptic Encephalopathy ◽  
Synaptic Function ◽  
Folate Metabolism ◽  
Folate Supplementation ◽  
Psychomotor Delay ◽  
Vitamin Therapy

AbstractSynaptic Ras GTPase-activating protein 1 (SYNGAP1), also called Ras-GAP 1 or RASA5, is a cerebral protein with a role in brain synaptic function. Its expression affects the development, structure, function, and plasticity of neurons. Mutations in the gene cause a neurodevelopment disorder termed mental retardation-type 5, also called SYNGAP1 syndrome. This syndrome can cause many neurological symptoms including pharmaco-resistant epilepsy, intellectual disability, language delay, and autism spectrum disorder. The syndrome naturally evolves as epileptic encephalopathy with handicap and low intellectual level. A treatment to control epilepsy, limit any decrease in social capacities, and improve intellectual development is really a challenging goal for these patients. The etiologic investigation performed in a 5-year-old girl with early epileptic absence seizures (onset at 6 months) and psychomotor delay (language) revealed a low methylenetetrahydrofolate level in cerebrospinal fluid in a lumbar puncture, confirmed by a second one (35 nmol/L and 50 nmol/L vs. 60–100 nmol/L normal), associated with normal blood and erythrocyte folate levels. Hyperhomocysteinemia, de vivo disease, and other metabolic syndromes were excluded by metabolic analysis. No genetic disorders (like methylenetetrahydrofolate reductase and methenyltetrahydrofolate synthetase) with folate metabolism were found. The physical examination showed only a minor kinetic ataxia. An oral folate (5-methyltetrahydrofolate) supplementation was started with oral vitamin therapy. The child showed good progress in language with this new treatment; epilepsy was well balanced with only one antiepileptic drug. The SYNGAP1 mutation was identified in this patient's genetic analysis. Since the start of folate supplementation/vitamin therapy, the patient's neurologic development has improved. To our knowledge, no association between these two pathologies has been linked and no patient with this SYNGAP1 mutation has ever showed much intellectual progress. Low cerebral methylenetetrahydrofolate levels could be associated with SYNGAP1 mutations. One of the hypotheses is the link of folate metabolism with epigenetic changes including methylation process. One inborn metabolic activity in folate metabolism may be associated with SYNGAP1 disease with epigenetic repercussions. Further studies should assess the link of SYNGAP1 and methyltetrahydrofolate and the evolution of SYNGAP1 patients with oral folate supplementation or vitamin therapy.

scholarly journals The Relationship Between Methylation Defects and Different Genetic Disorders: Two Case Reports

2016 ◽  
Author(s):  
Emine Aydın ◽  
Ahmet Cevdet Ceylan ◽  
Mehmet Sinan Beksaç
Keyword(s):  
Methylenetetrahydrofolate Reductase ◽  
Chromosomal Abnormalities ◽  
Case Reports ◽  
Genetic Disorders ◽  
Mthfr Gene ◽  
Folate Metabolism ◽  
Key Enzyme ◽  
Gene Switching ◽  
Methylation Defects ◽  
The Relationship

<p>5, 10-methylenetetrahydrofolate reductase (MTHFR) is a coding gene, for a key enzyme in methionine-homocysteine and folate metabolism. This pathway has been associated with gene specific DNA hypo and hypermethylation as a result of gene switching on or off.<br />Methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms are associated with folate metabolism disorders; such as, it results in an impaired DNA methylation and chromosomal abnormalities, gene deficiencies and structural anomalies. Here, we reported two cases of compound heterozygote and homozygote MTHFR gene mutation association with genetical disorders during the pregnancies.</p>

Case report: a child with cystic fibrosis and phenylketonuria

2020 ◽  
Vol 1 (2) ◽  
pp. 38-44
Author(s):  
Irina V. Vakhlova ◽  
Anastasia D. Kazachina ◽  
Olga A. Beglyanina
Keyword(s):  
Cystic Fibrosis ◽  
Case Report ◽  
Clinical Practice ◽  
Neonatal Screening ◽  
Genetic Disorders ◽  
Epileptiform Activity ◽  
Autism Spectrum ◽  
Speech Development ◽  
Inherited Disorders ◽  
Congenital Diseases

Background. In the international clinical practice there have been occasional reports of phenylketonuria (PKU) and cystic fibrosis (CF) found simultaneously in the same patient. Both PKU and CF are the inherited disorders characterized by autosomal recessive type of inheritance. Currently the combination of two or more inherited disorders in one patient is considered to be a clinical rarity.Case description. This is a clinical case of two genetic disorders, CF and PKU, combined in a 5-year old patient who had been followed up since birth. Owing to implementation of neonatal screening for inherited and congenital diseases into clinical practice, during the first month of life the infant was diagnosed with CF (diagnostically significant elevation of immunoreactive trypsin [IRT] at the initial [163.2 ng/mL] and repeat testing on day 21 of life [138.7 ng/mL]) and PKU (phenylalanine [PA] level 15.9 mg/dL). Both disorders have been confirmed by genetic tests, i.e., homozygous DelF508 mutation was found in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, and P281L mutation in the phenylalanine hydroxylase (PAH) gene was also present in homozygous state. Child’s parents strictly adhered to dietary and treatment recommendations. By the age of 5 years the child developed symptoms of neurological disorder and disorder of the respiratory system, cognitive impairment and delay in speech development, subclinical epileptiform activity with high risk of epilepsy, and chronic inflammation of the respiratory tract.Conclusion. This case report demonstrates the important role of neonatal screening in early diagnosis and timely start of therapy, and underscores the importance of continuous medication in such genetic disorders as CF and PKU. On the whole, such approach brings about a relative preservation of functioning of the most affected organs and systems. By the age of 5 years the child does not form bronchiectases, shows no signs of chronic hypoxia, nutritional deficiency or pronounced neurologic deficit, and is at low risk for the development of autism spectrum disorder. At the same time, the larger scale and longer-term observations are required in order to make the unequivocal conclusions about the prognosis of these diseases under conditions of modern-day medical follow-up.

scholarly journals “Guilt by association” is not competitive with genetic association for identifying autism risk genes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Margot Gunning ◽  
Paul Pavlidis
Keyword(s):  
Machine Learning ◽  
Genetic Association ◽  
Gene Networks ◽  
Rare Variants ◽  
Association Studies ◽  
Genetic Disorders ◽  
Autism Spectrum ◽  
Biological Data ◽  
Disease Genes ◽  
Risk Genes

AbstractDiscovering genes involved in complex human genetic disorders is a major challenge. Many have suggested that machine learning (ML) algorithms using gene networks can be used to supplement traditional genetic association-based approaches to predict or prioritize disease genes. However, questions have been raised about the utility of ML methods for this type of task due to biases within the data, and poor real-world performance. Using autism spectrum disorder (ASD) as a test case, we sought to investigate the question: can machine learning aid in the discovery of disease genes? We collected 13 published ASD gene prioritization studies and evaluated their performance using known and novel high-confidence ASD genes. We also investigated their biases towards generic gene annotations, like number of association publications. We found that ML methods which do not incorporate genetics information have limited utility for prioritization of ASD risk genes. These studies perform at a comparable level to generic measures of likelihood for the involvement of genes in any condition, and do not out-perform genetic association studies. Future efforts to discover disease genes should be focused on developing and validating statistical models for genetic association, specifically for association between rare variants and disease, rather than developing complex machine learning methods using complex heterogeneous biological data with unknown reliability.

scholarly journals Targeting Poison Exons to Treat Developmental and Epileptic Encephalopathy

2021 ◽  
pp. 1-6
Author(s):  
Miriam C. Aziz ◽  
Patricia N. Schneider ◽  
Gemma L. Carvill
Keyword(s):  
Alternative Splicing ◽  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
Autism Spectrum ◽  
Epileptic Encephalopathy ◽  
Nonsense Mediated Decay ◽  
Subsequent Degradation ◽  
Alternative Splicing Events ◽  
Genetic Epilepsies

Developmental and epileptic encephalopathies (DEEs) describe a subset of neurodevelopmental disorders categorized by refractory epilepsy that is often associated with intellectual disability and autism spectrum disorder. The majority of DEEs are now known to have a genetic basis with de novo coding variants accounting for the majority of cases. More recently, a small number of individuals have been identified with intronic <i>SCN1A</i> variants that result in alternative splicing events that lead to ectopic inclusion of poison exons (PEs). PEs are short highly conserved exons that contain a premature truncation codon, and when spliced into the transcript, lead to premature truncation and subsequent degradation by nonsense-mediated decay. The reason for the inclusion/exclusion of these PEs is not entirely clear, but research suggests an autoregulatory role in gene expression and protein abundance. This is seen in proteins such as RNA-binding proteins and serine/arginine-rich proteins. Recent studies have focused on targeting these PEs as a method for therapeutic intervention. Targeting PEs using antisense oligonucleotides (ASOs) has shown to be effective in modulating alternative splicing events by decreasing the amount of transcripts harboring PEs, thus increasing the abundance of full-length transcripts and thereby the amount of protein in haploinsufficient genes implicated in DEE. In the age of personalized medicine, cellular and animal models of the genetic epilepsies have become essential in developing and testing novel precision therapeutics, including PE-targeting ASOs in a subset of DEEs.

scholarly journals Synergistic inhibition of histone modifiers produces therapeutic effects in adult Shank3-deficient mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Freddy Zhang ◽  
Benjamin Rein ◽  
Ping Zhong ◽  
Treefa Shwani ◽  
Megan Conrow-Graham ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Social Preference ◽  
Intervention Strategy ◽  
Autism Spectrum ◽  
Synaptic Function ◽  
Pharmacological Intervention ◽  
Therapeutic Effects ◽  
Male Mice ◽  
Behavioral Abnormalities ◽  
Deficient Mice

AbstractAutism spectrum disorder (ASD) is a lifelong developmental disorder characterized by social deficits and other behavioral abnormalities. Dysregulation of epigenetic processes, such as histone modifications and chromatin remodeling, have been implicated in ASD pathology, and provides a promising therapeutic target for ASD. Haploinsufficiency of the SHANK3 gene is causally linked to ASD, so adult (3–5 months old) Shank3-deficient male mice were used in this drug discovery study. We found that combined administration of the class I histone deacetylase inhibitor Romidepsin and the histone demethylase LSD1 inhibitor GSK-LSD1 persistently ameliorated the autism-like social preference deficits, while each individual drug alone was largely ineffective. Another behavioral abnormality in adult Shank3-deficient male mice, heightened aggression, was also alleviated by administration of the dual drugs. Furthermore, Romidepsin/GSK-LSD1 treatment significantly increased transcriptional levels of NMDA receptor subunits in prefrontal cortex (PFC) of adult Shank3-deficient mice, resulting in elevated synaptic expression of NMDA receptors and the restoration of NMDAR synaptic function in PFC pyramidal neurons. These results have offered a novel pharmacological intervention strategy for ASD beyond early developmental periods.

scholarly journals Cerebrospinal fluid liquid biopsy for detecting somatic mosaicism in brain

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Zimeng Ye ◽  
Zac Chatterton ◽  
Jahnvi Pflueger ◽  
John A Damiano ◽  
Lara McQuillan ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Liquid Biopsy ◽  
Somatic Mutations ◽  
Somatic Mosaicism ◽  
Autism Spectrum ◽  
Brain Diseases ◽  
Cell Free Dna ◽  
Free Dna ◽  
Subcortical Band Heterotopia ◽  
Fluid Cell

Abstract Brain somatic mutations are an increasingly recognized cause of epilepsy, brain malformations and autism spectrum disorders and may be a hidden cause of other neurodevelopmental and neurodegenerative disorders. At present, brain mosaicism can be detected only in the rare situations of autopsy or brain biopsy. Liquid biopsy using cell-free DNA derived from cerebrospinal fluid has detected somatic mutations in malignant brain tumours. Here, we asked if cerebrospinal fluid liquid biopsy can be used to detect somatic mosaicism in non-malignant brain diseases. First, we reliably quantified cerebrospinal fluid cell-free DNA in 28 patients with focal epilepsy and 28 controls using droplet digital PCR. Then, in three patients we identified somatic mutations in cerebrospinal fluid: in one patient with subcortical band heterotopia the LIS1 p. Lys64* variant at 9.4% frequency; in a second patient with focal cortical dysplasia the TSC1 p. Phe581His*6 variant at 7.8% frequency; and in a third patient with ganglioglioma the BRAF p. Val600Glu variant at 3.2% frequency. To determine if cerebrospinal fluid cell-free DNA was brain-derived, whole-genome bisulphite sequencing was performed and brain-specific DNA methylation patterns were found to be significantly enriched (P = 0.03). Our proof of principle study shows that cerebrospinal fluid liquid biopsy is valuable in investigating mosaic neurological disorders where brain tissue is unavailable.

scholarly journals Cerebrospinal fluid abnormalities in developmental and epileptic encephalopathy with a de novo CDK19 variant

2020 ◽  
Vol 6 (6) ◽  
pp. e527
Author(s):  
Yuji Sugawara ◽  
Tomoko Mizuno ◽  
Kengo Moriyama ◽  
Hisako Ishiwata ◽  
Mitsuhiro Kato ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
De Novo ◽  
Epileptic Encephalopathy

scholarly journals Synaptic and Gene Regulatory Mechanisms in Schizophrenia, Autism, and 22q11.2 CNV Mediated Risk for Neuropsychiatric Disorders

2019 ◽  
Author(s):  
Jennifer K. Forsyth ◽  
Daniel Nachun ◽  
Michael J. Gandal ◽  
Daniel H. Geschwind ◽  
Ariana E. Anderson ◽  
...  
Keyword(s):  
Gene Networks ◽  
Disease Risk ◽  
Neuropsychiatric Disorders ◽  
Autism Spectrum ◽  
Synaptic Function ◽  
Protein Interaction Data ◽  
Regulatory Pathways ◽  
Polygenic Risk ◽  
Risk Variants ◽  
Gene Regulatory

AbstractBackground22q11.2 copy number variants (CNVs) are among the most highly penetrant genetic risk variants for developmental neuropsychiatric disorders such as schizophrenia (SCZ) and autism spectrum disorder (ASD). However, the specific mechanisms through which they confer risk remain unclear.MethodsUsing a functional genomics approach, we integrated transcriptomic data from the developing human brain, genome-wide association findings for SCZ and ASD, protein interaction data, and pathophysiological signatures of SCZ and ASD to: 1) organize genes into the developmental cellular and molecular systems within which they operate; 2) identify neurodevelopmental processes associated with polygenic risk for SCZ and ASD across the allelic frequency spectrum; and 3) elucidate pathways and individual genes through which 22q11.2 CNVs may confer risk for each disorder.ResultsPolygenic risk for SCZ and ASD converged on partially overlapping gene networks involved in synaptic function and transcriptional regulation, with ASD risk variants additionally enriched for networks involved in neuronal differentiation during fetal development. The 22q11.2 locus formed a large protein network that disproportionately affected SCZ- and ASD-associated neurodevelopmental networks, including loading highly onto synaptic and gene regulatory pathways. SEPT5, PI4KA, and SNAP29 genes are candidate drivers of 22q11.2 synaptic pathology relevant to SCZ and ASD, and DGCR8 and HIRA are candidate drivers of disease-relevant alterations in gene regulation.ConclusionsThe current approach provides a powerful framework to identify neurodevelopmental processes affected by diverse risk variants for SCZ and ASD, and elucidate the mechanisms through which highly penetrant multi-gene CNVs contribute to disease risk.

ROLE OF GENETIC POLYMORPHISMS ASSOCIATED WITH THROMBOPHILIA, PROTHROMBOTIC STATE AND FOLATE CYCLE DISTURBANCES IN WOMEN WITH REPRODUCTIVE DISORDERS

2017 ◽  
Author(s):  
А. Киселева ◽  
Е. Бутина ◽  
Г. Зайцева ◽  
Е. Попонина ◽  
С. Игнатьев ◽  
...  
Keyword(s):  
Genetic Disorders ◽  
Folate Metabolism ◽  
Clear Understanding ◽  
Reproductive Disorders ◽  
Primary Infertility ◽  
Risk Alleles ◽  
Heterozygous Form ◽  
Folate Cycle ◽  
Pai 1

Введение. Причины осложнения беременности достаточно многообразны: хромосомные и генетические нарушения, эндокринопатии, анатомические, инфекционные, иммунные и тромбофилические факторы. До настоящего времени нет четкого представления об истинных составляющих нарушения гестационного процесса. Материалы и методы. Проведено исследование аллелей, ассоциированных с тромбофилией и протромботическими состояниями, у 629 женщин и генов фолатного обмена у 277 женщин с отягощенным акушерским анамнезом. Результаты. Проанализирован характер распределения «аллелей риска» у женщин с первичным бесплодием, осложненными родами, неразвивающимися беременностями и у женщин без отягощенного акушерского анамнеза. Представлены данные о частоте встречаемости генетических мутаций, ассоциированных с тромбофилией (F2, F5), протромботическими состояниями (F7, F13, FGB, ITGA-2, ITGB-3, PAI-1) и нарушениями фолатного обмена (MTFFR, MTR, MTRR) у женщин с репродуктивными расстройствами. Заключение. Обнаружены статистически значимые различия в частоте распределения гетерозиготной формы полиморфизма ITGB3 у женщин с первичным бесплодием и осложненными родами в сравнении с женщинами без репродуктивных неудач. Влияние других полиморфных генов, ассоциированных с тромбофилией, протромботическими состояниями и нарушениями фолатного обмена, на наступление, течение и исход беременности не подтверждено. Introduction. The causes of pregnancy complications are quite multiformous: chromosomal and genetic disorders, endocrinopathies, anatomical, infectious, immune and thrombophilic factors. Until now there is no clear understanding of true components of gestational disorders. Materials and methods. We studied alleles associated with thrombophilia and prothrombotic conditions (in 629 women) and folate metabolism genes (in 277 women) with burdened obstetrical anamnesis. Results. The distribution of «risk alleles» in women with primary infertility, complicated delivery, non-developing pregnancy and at women without aggravated obstetric history was analyzed. Data about incidence of genetic mutations associated with thrombophilia (F2, F5), prothrombotic states (F7, F13, FGB, ITGA-2, ITGB-3, PAI-1) and folate metabolism disturbances (MTFFR, MTR, MTRR) in women with reproductive disorders are presented. Conclusion. Statistically signifi cant diff erences in distribution rate of heterozygous form of ITGB3 polymorphism in women with primary infertility and complicated delivery in comparison with women without reproductive failures were found. Impact of other polymorphic genes associated with thrombophilia, prothrombotic states and disturbances of folate metabolism to onset, gestation course and outcome of pregnancy was not proved.

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