scholarly journals Intellectual Disability and Brain Creatine Deficit: Phenotyping of the Genetic Mouse Model for GAMT Deficiency

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1201
Author(s):  
Luigia Rossi ◽  
Francesca Nardecchia ◽  
Francesca Pierigè ◽  
Rossella Ventura ◽  
Claudia Carducci ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Mouse Model ◽  
Clinical Symptoms ◽  
Global Developmental Delay ◽  
Behavioral Alterations ◽  
Biochemical Alterations ◽  
Bodily Fluids ◽  
Genetic Mouse Model ◽  
Gamt Deficiency ◽  
Pathogenic Variants

Guanidinoacetate methyltransferase deficiency (GAMT-D) is one of three cerebral creatine (Cr) deficiency syndromes due to pathogenic variants in the GAMT gene (19p13.3). GAMT-D is characterized by the accumulation of guanidinoacetic acid (GAA) and the depletion of Cr, which result in severe global developmental delay (and intellectual disability), movement disorder, and epilepsy. The GAMT knockout (KO) mouse model presents biochemical alterations in bodily fluids, the brain, and muscles, including increased GAA and decreased Cr and creatinine (Crn) levels, which are similar to those observed in humans. At the behavioral level, only limited and mild alterations have been reported, with a large part of analyzed behaviors being unaffected in GAMT KO as compared with wild-type mice. At the cerebral level, decreased Cr and Crn and increased GAA and other guanidine compound levels have been observed. Nevertheless, the effects of Cr deficiency and GAA accumulation on many neurochemical, morphological, and molecular processes have not yet been explored. In this review, we summarize data regarding behavioral and cerebral GAMT KO phenotypes, and focus on uncharted behavioral alterations that are comparable with the clinical symptoms reported in GAMT-D patients, including intellectual disability, poor speech, and autistic-like behaviors, as well as unexplored Cr-induced cerebral alterations.

scholarly journals Treatable inherited metabolic disorders causing intellectual disability: 2021 review and digital app

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Eva M. M. Hoytema van Konijnenburg ◽  
Saskia B. Wortmann ◽  
Marina J. Koelewijn ◽  
Laura A. Tseng ◽  
Roderick Houben ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Metabolic Disorders ◽  
Clinical Symptoms ◽  
Early Recognition ◽  
Diagnostic Algorithm ◽  
Global Developmental Delay ◽  
Digital Tool ◽  
Enzyme Replacement ◽  
Published Evidence ◽  
Inherited Metabolic Disorders

Abstract Background The Treatable ID App was created in 2012 as digital tool to improve early recognition and intervention for treatable inherited metabolic disorders (IMDs) presenting with global developmental delay and intellectual disability (collectively ‘treatable IDs’). Our aim is to update the 2012 review on treatable IDs and App to capture the advances made in the identification of new IMDs along with increased pathophysiological insights catalyzing therapeutic development and implementation. Methods Two independent reviewers queried PubMed, OMIM and Orphanet databases to reassess all previously included disorders and therapies and to identify all reports on Treatable IDs published between 2012 and 2021. These were included if listed in the International Classification of IMDs (ICIMD) and presenting with ID as a major feature, and if published evidence for a therapeutic intervention improving ID primary and/or secondary outcomes is available. Data on clinical symptoms, diagnostic testing, treatment strategies, effects on outcomes, and evidence levels were extracted and evaluated by the reviewers and external experts. The generated knowledge was translated into a diagnostic algorithm and updated version of the App with novel features. Results Our review identified 116 treatable IDs (139 genes), of which 44 newly identified, belonging to 17 ICIMD categories. The most frequent therapeutic interventions were nutritional, pharmacological and vitamin and trace element supplementation. Evidence level varied from 1 to 3 (trials, cohort studies, case–control studies) for 19% and 4–5 (case-report, expert opinion) for 81% of treatments. Reported effects included improvement of clinical deterioration in 62%, neurological manifestations in 47% and development in 37%. Conclusion The number of treatable IDs identified by our literature review increased by more than one-third in eight years. Although there has been much attention to gene-based and enzyme replacement therapy, the majority of effective treatments are nutritional, which are relatively affordable, widely available and (often) surprisingly effective. We present a diagnostic algorithm (adjustable to local resources and expertise) and the updated App to facilitate a swift and accurate workup, prioritizing treatable IDs. Our digital tool is freely available as Native and Web App (www.treatable-id.org) with several novel features. Our Treatable ID endeavor contributes to the Treatabolome and International Rare Diseases Research Consortium goals, enabling clinicians to deliver rapid evidence-based interventions to our rare disease patients.

scholarly journals Attention Deficit Hyperactivity and Autism Spectrum Disorders as the Core Symptoms of AUTS2 Syndrome: Description of Five New Patients and Update of the Frequency of Manifestations and Genotype-Phenotype Correlation

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1360
Author(s):  
Carolina Sanchez-Jimeno ◽  
Fiona Blanco-Kelly ◽  
Fermina López-Grondona ◽  
Rebeca Losada-Del Pozo ◽  
Beatriz Moreno ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Attention Deficit ◽  
Autism Spectrum ◽  
Global Developmental Delay ◽  
Sequence Variants ◽  
Loss Of Function ◽  
Phenotype Correlation ◽  
Feeding Difficulties ◽  
Pathogenic Variants ◽  
Genotype Phenotype Correlation

Haploinsufficiency of AUTS2 has been associated with a syndromic form of neurodevelopmental delay characterized by intellectual disability, autistic features, and microcephaly, also known as AUTS2 syndrome. While the phenotype associated with large deletions and duplications of AUTS2 is well established, clinical features of patients harboring AUTS2 sequence variants have not been extensively described. In this study, we describe the phenotype of five new patients with AUTS2 pathogenic variants, three of them harboring loss-of-function sequence variants. The phenotype of the patients was characterized by attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) or autistic features and mild global developmental delay (GDD) or intellectual disability (ID), all in 4/5 patients (80%), a frequency higher than previously reported for ADHD and autistic features. Microcephaly and short stature were found in 60% of the patients; and feeding difficulties, generalized hypotonia, and ptosis, were each found in 40%. We also provide the aggregated frequency of the 32 items included in the AUTS2 syndrome severity score (ASSS) in patients currently reported in the literature. The main characteristics of the syndrome are GDD/ID in 98% of patients, microcephaly in 65%, feeding difficulties in 62%, ADHD or hyperactivity in 54%, and autistic traits in 52%. Finally, using the location of 31 variants from the literature together with variants from the five patients, we found significantly higher ASSS values in patients with pathogenic variants affecting the 3′ end of the gene, confirming the genotype-phenotype correlation initially described.

scholarly journals Clinical and Genetic Characteristics and Prenatal Diagnosis of Rare Monogenic Global Developmental Delay and Intellectual Disability.

2020 ◽  
Author(s):  
Liling Lin ◽  
Ying Zhang ◽  
Hong Pan ◽  
Jingmin Wang ◽  
Yu Qi ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Prenatal Diagnosis ◽  
Developmental Delay ◽  
Hot Spot ◽  
Disease Onset ◽  
Genetic Diagnosis ◽  
Global Developmental Delay ◽  
Genetic Characteristics ◽  
Pathogenic Variants

Abstract Background: The estimated worldwide prevalence of global developmental delay (GDD) and intellectual disability (ID) is 1-3%. Rare monogenic GDD/ID is poorly characterized because its low prevalence limits research. In this study, we aimed to describe the diagnostic courses and clinical and genetic characteristics of a cohort with rare monogenic GDD/ID.Method:We retrospectively analyzed the diagnostic courses, clinical characteristics, and genetic spectra of rare monogenic GDD/ID patients. We also conducted a follow-up study on prenatal diagnosis in these families. Mutation pathogenicity was interpreted by molecular geneticists and clinicians according to the guidelines of the American College of Medical Genetics and Genomics. Results:Among 108 patients with rare monogenic GDD/ID, it often took 0.5-4 years and 3-5 referrals to obtain a genetic diagnosis after disease onset. Onset typically occurred before 6 years of age, and patients usually presented moderate to severe GDD/ID. The most common coexisting conditions were epilepsy (68%), facial dysmorphism (14%) and microcephaly (13%). In total, 149 different pathogenic variants were found in 81 different genes among the 108 pedigrees, and 71 variants were novel. The most common inheritance patterns in this outbred Chinese population were autosomal recessive (AR; 46.3%), autosomal dominant (AD; 37%), and X-linked (XL; 16.7%). GLB1, PLA2G6, SCN2A, SHANK3 and STXBP1 were important causal genes. Hot-spot mutations were rarely found. By the follow-up, 43 families, including 24 ARID, 13 ADID and 6 XLID families, had undergone prenatal diagnosis. The offspring of 6 ARID, 2 ADID and 2 XLID families had the same pathogenic variants as the probands.Conclusion:Rare monogenic GDD/ID is characterized by early onset, relatively severe symptoms, great clinical variability and genetic heterogeneity. Moreover, timely referrals to genetic counseling and prenatal diagnostic laboratories are important for affected families planning to have additional children.

scholarly journals Neurological Disorders Associated with WWOX Germline Mutations—A Comprehensive Overview

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 824
Author(s):  
Ehud Banne ◽  
Baraa Abudiab ◽  
Sara Abu-Swai ◽  
Srinivasa Rao Repudi ◽  
Daniel J. Steinberg ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Clinical Symptoms ◽  
Epileptic Encephalopathy ◽  
Global Developmental Delay ◽  
Comprehensive Overview ◽  
Pathogenic Variants ◽  
The Impact ◽  
Underlying Pathophysiology ◽  
Wwox Gene ◽  
Cross Reference

The transcriptional regulator WW domain-containing oxidoreductase (WWOX) is a key player in a number of cellular and biological processes including tumor suppression. Recent evidence has emerged associating WWOX with non-cancer disorders. Patients harboring pathogenic germline bi-allelic WWOX variants have been described with the rare devastating neurological syndromes autosomal recessive spinocerebellar ataxia 12 (SCAR12) (6 patients) and WWOX-related epileptic encephalopathy (DEE28 or WOREE syndrome) (56 patients). Individuals with these syndromes present with a highly heterogenous clinical spectrum, the most common clinical symptoms being severe epileptic encephalopathy and profound global developmental delay. Knowledge of the underlying pathophysiology of these syndromes, the range of variants of the WWOX gene and its genotype-phenotype correlations is limited, hampering therapeutic efforts. Therefore, there is a critical need to identify and consolidate all the reported variants in WWOX to distinguish between disease-causing alleles and their associated severity, and benign variants, with the aim of improving diagnosis and increasing therapeutic efforts. Here, we provide a comprehensive review of the literature on WWOX, and analyze the pathogenic variants from published and unpublished reports by collecting entries from the ClinVar, DECIPHER, VarSome, and PubMed databases to generate the largest dataset of WWOX pathogenic variants. We estimate the correlation between variant type and patient phenotype, and delineate the impact of each variant, and used GnomAD to cross reference these variants found in the general population. From these searches, we generated the largest published cohort of WWOX individuals. We conclude with a discussion on potential personalized medicine approaches to tackle the devastating disorders associated with WWOX mutations.

scholarly journals De novo pathogenic variants inCHAMP1are associated with global developmental delay, intellectual disability, and dysmorphic facial features

2015 ◽  
Vol 2 (1) ◽  
pp. a000661 ◽  
Author(s):  
Akemi J. Tanaka ◽  
Megan T. Cho ◽  
Kyle Retterer ◽  
Julie R. Jones ◽  
Catherine Nowak ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
De Novo ◽  
Global Developmental Delay ◽  
Facial Features ◽  
Pathogenic Variants

scholarly journals Shukla-Vernon Syndrome: A Second Family with a Novel Variant in the BCORL1 Gene

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 452
Author(s):  
Babylakshmi Muthusamy ◽  
Anikha Bellad ◽  
Satish Chandra Girimaji ◽  
Akhilesh Pandey
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Protein Complexes ◽  
Neurodevelopmental Disorder ◽  
Missense Variant ◽  
Global Developmental Delay ◽  
Dysmorphic Features ◽  
Pathogenic Variants ◽  
Behavioral Abnormalities ◽  
Novel Variant

Shukla-Vernon syndrome (SHUVER) is an extremely rare neurodevelopmental disorder characterized by global developmental delay, intellectual disability, behavioral anomalies, and dysmorphic features. Pathogenic variants in the BCORL1 gene have been identified as the molecular cause for this disorder. The BCORL1 gene encodes for BCL-6 corepressor-like protein 1, a transcriptional corepressor that is an integral component of protein complexes involved in transcription repression. In this study, we report an Indian family with two male siblings with features of Shukla-Vernon syndrome. The patients exhibited global developmental delay, intellectual disability, kyphosis, seizures, and dysmorphic features including bushy prominent eyebrows with synophrys, sharp beaked prominent nose, protuberant lower jaw, squint, and hypoplastic ears with fused ear lobes. No behavioral abnormalities were observed. Whole exome sequencing revealed a novel potentially pathogenic arginine to cysteine substitution (p.Arg1265Cys) in the BCORL1 protein. This is the second report of Shukla-Vernon syndrome with a novel missense variant in the BCORL1 gene. Our study confirms and expands the phenotypes and genotypes described previously for this syndrome and should aid in diagnosis and genetic counselling of patients and their families.

1734-P: High Dietary Fat Intake Exacerbates Insulin Resistance in a Type 2 Diabetes Genetic Mouse Model

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 1734-P
Author(s):  
AUSTIN REILLY ◽  
SHIJUN YAN ◽  
ALEXA J. LONCHARICH ◽  
HONGXIA REN
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Mouse Model ◽  
Dietary Fat ◽  
Fat Intake ◽  
Dietary Fat Intake ◽  
Genetic Mouse Model

scholarly journals Carrot Supplementation Improves Blood Pressure and Reduces Aortic Root Lesions in an Atherosclerosis-Prone Genetic Mouse Model

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1181
Author(s):  
Raffaella Soleti ◽  
Marine Coué ◽  
Charlotte Trenteseaux ◽  
Gregory Hilairet ◽  
Lionel Fizanne ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Mouse Model ◽  
Aortic Root ◽  
De Novo ◽  
Body Weight Gain ◽  
Density Lipoprotein ◽  
De Novo Lipogenesis ◽  
Hemodynamic Parameters ◽  
Cellular Models ◽  
Genetic Mouse Model

Epidemiological studies have shown that carrot consumption may be associated with a lower risk of developing several metabolic dysfunctions. Our group previously determined that the Bolero (Bo) carrot variety exhibited vascular and hepatic tropism using cellular models of cardiometabolic diseases. The present study evaluated the potential metabolic and cardiovascular protective effect of Bo, grown under two conditions (standard and biotic stress conditions (BoBS)), in apolipoprotein E-knockout (ApoE−/−) mice fed with high fat diet (HFD). Effects on metabolic/hemodynamic parameters and on atherosclerotic lesions have been assessed. Both Bo and BoBS decreased plasma triglyceride and expression levels of genes implicated in hepatic de novo lipogenesis and lipid oxidation. BoBS supplementation decreased body weight gain, secretion of very-low-density lipoprotein, and increased cecal propionate content. Interestingly, Bo and BoBS supplementation improved hemodynamic parameters by decreasing systolic, diastolic, and mean blood pressure. Moreover, Bo improved cardiac output. Finally, Bo and BoBS substantially reduced the aortic root lesion area. These results showed that Bo and BoBS enriched diets corrected most of the metabolic and cardiovascular disorders in an atherosclerosis-prone genetic mouse model and may therefore represent an interesting nutritional approach for the prevention of cardiovascular diseases.

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