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1.
Cell ; 180(3): 568-584.e23, 2020 02 06.
Article in English | MEDLINE | ID: mdl-31981491

ABSTRACT

We present the largest exome sequencing study of autism spectrum disorder (ASD) to date (n = 35,584 total samples, 11,986 with ASD). Using an enhanced analytical framework to integrate de novo and case-control rare variation, we identify 102 risk genes at a false discovery rate of 0.1 or less. Of these genes, 49 show higher frequencies of disruptive de novo variants in individuals ascertained to have severe neurodevelopmental delay, whereas 53 show higher frequencies in individuals ascertained to have ASD; comparing ASD cases with mutations in these groups reveals phenotypic differences. Expressed early in brain development, most risk genes have roles in regulation of gene expression or neuronal communication (i.e., mutations effect neurodevelopmental and neurophysiological changes), and 13 fall within loci recurrently hit by copy number variants. In cells from the human cortex, expression of risk genes is enriched in excitatory and inhibitory neuronal lineages, consistent with multiple paths to an excitatory-inhibitory imbalance underlying ASD.


Subject(s)
Autistic Disorder/genetics , Cerebral Cortex/growth & development , Exome Sequencing/methods , Gene Expression Regulation, Developmental , Neurobiology/methods , Case-Control Studies , Cell Lineage , Cohort Studies , Exome , Female , Gene Frequency , Genetic Predisposition to Disease , Humans , Male , Mutation, Missense , Neurons/metabolism , Phenotype , Sex Factors , Single-Cell Analysis/methods
2.
Nat Rev Genet ; 21(6): 367-376, 2020 06.
Article in English | MEDLINE | ID: mdl-32317787

ABSTRACT

Autism spectrum disorder (ASD) is often grouped with other brain-related phenotypes into a broader category of neurodevelopmental disorders (NDDs). In clinical practice, providers need to decide which genes to test in individuals with ASD phenotypes, which requires an understanding of the level of evidence for individual NDD genes that supports an association with ASD. Consensus is currently lacking about which NDD genes have sufficient evidence to support a relationship to ASD. Estimates of the number of genes relevant to ASD differ greatly among research groups and clinical sequencing panels, varying from a few to several hundred. This Roadmap discusses important considerations necessary to provide an evidence-based framework for the curation of NDD genes based on the level of information supporting a clinically relevant relationship between a given gene and ASD.


Subject(s)
Autism Spectrum Disorder/genetics , Evidence-Based Medicine/methods , Genetic Association Studies/methods , Brain/growth & development , Cognition/physiology , Humans , Intellectual Disability/genetics
3.
Hum Mol Genet ; 31(4): 625-637, 2022 02 21.
Article in English | MEDLINE | ID: mdl-34559195

ABSTRACT

Individuals with Phelan-McDermid syndrome (PMS) present with a wide range of developmental, medical, cognitive and behavioral abnormalities. Previous literature has begun to elucidate genotype-phenotype associations that may contribute to the wide spectrum of features. Here, we report results of genotype-phenotype associations in a cohort of 170 individuals with PMS. Genotypes were defined as Class I deletions (including SHANK3 only or SHANK3 with ARSA and/or ACR and RABL2B), Class II deletions (all other deletions) or sequence variants. Phenotype data were derived prospectively from direct evaluation, caregiver interview and questionnaires, and medical history. Analyses revealed individuals with Class I deletions or sequence variants had fewer delayed developmental milestones and higher cognitive ability compared to those with Class II deletions but had more skill regressions. Individuals with Class II deletions were more likely to have a variety of medical features, including renal abnormalities, spine abnormalities, and ataxic gait. Those with Class I deletions or sequence variants were more likely to have psychiatric diagnoses including bipolar disorder, depression, and schizophrenia. Autism spectrum disorder diagnoses did not differ between groups. This study represents the largest and most rigorous genotype-phenotype analysis in PMS to date and provides important information for considering clinical functioning, trajectories and comorbidities as a function of specific genetic alteration.


Subject(s)
Autism Spectrum Disorder , Chromosome Disorders , Autism Spectrum Disorder/genetics , Chromosome Deletion , Chromosome Disorders/genetics , Chromosomes, Human, Pair 22/genetics , Genetic Association Studies , Humans
4.
Cell Tissue Bank ; 25(2): 619-623, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38141131

ABSTRACT

The cornea transplant is considered the most frequently performed type of transplant in the world, with a demand that has been increasing in recent years. An observational descriptive study was conducted, focusing on the ocular tissue extracted from cadaveric donors from January 2019 to December 2021 at the Red Cross Eye Bank in Medellin, Colombia. This is the first epidemiological characterization of corneal donor tissues within the eye banks of our city, where high rates of violence-related deaths explain that tissue donors are mostly young individuals. This, in turn, results in excellent counts of endothelial cells and tissue viability in their microscopic studies. Additionally, there are lower rates of discarded tissues compared to similar studies.


Subject(s)
Cornea , Corneal Transplantation , Eye Banks , Tissue Donors , Colombia , Humans , Adult , Female , Middle Aged , Male , Eye Banks/statistics & numerical data , Aged , Young Adult , Adolescent , Aged, 80 and over , Cities
5.
Am J Med Genet A ; 191(8): 2015-2044, 2023 08.
Article in English | MEDLINE | ID: mdl-37392087

ABSTRACT

Phelan-McDermid syndrome (PMS) is a genetic condition caused by SHANK3 haploinsufficiency and characterized by a wide range of neurodevelopmental and systemic manifestations. The first practice parameters for assessment and monitoring in individuals with PMS were published in 2014; recently, knowledge about PMS has grown significantly based on data from longitudinal phenotyping studies and large-scale genotype-phenotype investigations. The objective of these updated clinical management guidelines was to: (1) reflect the latest in knowledge in PMS and (2) provide guidance for clinicians, researchers, and the general community. A taskforce was established with clinical experts in PMS and representatives from the parent community. Experts joined subgroups based on their areas of specialty, including genetics, neurology, neurodevelopment, gastroenterology, primary care, physiatry, nephrology, endocrinology, cardiology, gynecology, and dentistry. Taskforce members convened regularly between 2021 and 2022 and produced specialty-specific guidelines based on iterative feedback and discussion. Taskforce leaders then established consensus within their respective specialty group and harmonized the guidelines. The knowledge gained over the past decade allows for improved guidelines to assess and monitor individuals with PMS. Since there is limited evidence specific to PMS, intervention mostly follows general guidelines for treating individuals with developmental disorders. Significant evidence has been amassed to guide the management of comorbid neuropsychiatric conditions in PMS, albeit mainly from caregiver report and the experience of clinical experts. These updated consensus guidelines on the management of PMS represent an advance for the field and will improve care in the community. Several areas for future research are also highlighted and will contribute to subsequent updates with more refined and specific recommendations as new knowledge accumulates.


Subject(s)
Chromosome Disorders , Humans , Phenotype , Chromosome Disorders/diagnosis , Chromosome Disorders/epidemiology , Chromosome Disorders/genetics , Chromosome Deletion , Nerve Tissue Proteins/genetics , Chromosomes, Human, Pair 22/genetics
6.
Genet Med ; 24(9): 1899-1908, 2022 09.
Article in English | MEDLINE | ID: mdl-35616647

ABSTRACT

PURPOSE: Neurodevelopmental disorders (NDDs), such as intellectual disability (ID) and autism spectrum disorder (ASD), exhibit genetic and phenotypic heterogeneity, making them difficult to differentiate without a molecular diagnosis. The Clinical Genome Resource Intellectual Disability/Autism Gene Curation Expert Panel (GCEP) uses systematic curation to distinguish ID/ASD genes that are appropriate for clinical testing (ie, with substantial evidence supporting their relationship to disease) from those that are not. METHODS: Using the Clinical Genome Resource gene-disease validity curation framework, the ID/Autism GCEP classified genes frequently included on clinical ID/ASD testing panels as Definitive, Strong, Moderate, Limited, Disputed, Refuted, or No Known Disease Relationship. RESULTS: As of September 2021, 156 gene-disease pairs have been evaluated. Although most (75%) were determined to have definitive roles in NDDs, 22 (14%) genes evaluated had either Limited or Disputed evidence. Such genes are currently not recommended for use in clinical testing owing to the limited ability to assess the effect of identified variants. CONCLUSION: Our understanding of gene-disease relationships evolves over time; new relationships are discovered and previously-held conclusions may be questioned. Without periodic re-examination, inaccurate gene-disease claims may be perpetuated. The ID/Autism GCEP will continue to evaluate these claims to improve diagnosis and clinical care for NDDs.


Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Intellectual Disability , Neurodevelopmental Disorders , Autism Spectrum Disorder/diagnosis , Autism Spectrum Disorder/genetics , Autistic Disorder/diagnosis , Autistic Disorder/genetics , Humans , Intellectual Disability/diagnosis , Intellectual Disability/genetics , Neurodevelopmental Disorders/genetics
7.
Am J Med Genet A ; 182(1): 213-218, 2020 01.
Article in English | MEDLINE | ID: mdl-31729143

ABSTRACT

Nuclear receptor subfamily 2 group F member 1 (NR2F1) is an orphan receptor and transcriptional regulator that is involved in neurogenesis, visual processing and development, and cortical patterning. Alterations in NR2F1 cause Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS), a recently described autosomal dominant disorder characterized by intellectual and developmental disabilities and optic atrophy. This study describes the clinical and neurocognitive features of an individual with a de novo nonsense variant in NR2F1 (NM_005654.5:c.82C > T, p.Gln28*), identified by whole exome sequencing. The patient was diagnosed with autism spectrum disorder (ASD) and unlike most previously reported cases, he had no developmental delay, superior verbal abilities (verbal IQ = 141), and high educational attainment despite reduced nonverbal abilities (nonverbal IQ = 63). He had optic nerve hypoplasia with minimal visual impairment as well as mild dysmorphic features. Compared to both age-matched individuals with ASD and healthy controls, the patient showed reductions in manual motor speed, accuracy of saccadic eye movements, and rates of successful behavioral response inhibition. Although the majority of previously reported cases of BBSOAS have been associated with more global intellectual dysfunction, we report on a patient with selective disruption of nonverbal abilities and superior verbal abilities.


Subject(s)
COUP Transcription Factor I/genetics , Developmental Disabilities/genetics , Intellectual Disability/genetics , Optic Atrophy/genetics , Adult , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/physiopathology , Codon, Nonsense/genetics , Developmental Disabilities/physiopathology , Female , Genetic Predisposition to Disease , Humans , Intellectual Disability/physiopathology , Male , Optic Atrophy/physiopathology , Phenotype , Exome Sequencing , Young Adult
8.
J Neurochem ; 150(3): 330-340, 2019 08.
Article in English | MEDLINE | ID: mdl-30748001

ABSTRACT

Cre/loxP recombination is a widely used approach to study gene function in vivo, using mice models expressing the Cre recombinase under the control of specific promoters or through viral delivery of Cre-expressing constructs. A profuse literature on transgenic mouse lines points out the deleterious effects of Cre expression in various cell types and tissues, presumably by acting on illegitimate loxP-like sites present in the genome. However, most studies reporting the consequences of Cre-lox gene invalidation often omit adequate controls to exclude the potential toxic effects of Cre, compromising the interpretation of data. In this study, we report the anatomical, neurochemical, and behavioral consequences in mice of adeno-associated virus (AAV)-mediated Cre expression in the dopaminergic nuclei substantia nigra, at commonly used viral titers (3 × 109 genome copies/0.3 µL or 2 × 109 genome copies/0.6 µL). We found that injecting AAV-eGFP-Cre into the SN engendered drastic and reproducible modifications of behavior, with increased basal locomotor activity as well as impaired locomotor response to cocaine compared to AAV-eGFP-injected controls. Cre expression in the SN induced a massive decrease in neuronal populations of both pars compacta and pars reticulata and dopamine depletion in the nigrostriatal pathway. This anatomical injury was associated with typical features of programmed cell death, including an increase in DNA break markers, evidence of apoptosis, and disrupted macroautophagy. These observations underscore the need for careful control of Cre toxicity in the brain and the reassessment of previous studies. In addition, our findings suggest that Cre-mediated ablation may constitute an efficient tool to explore the function of specific cell populations and areas in the brain, and the impact of neurodegeneration in these populations.


Subject(s)
Integrases , Neurons/pathology , Substantia Nigra/metabolism , Substantia Nigra/pathology , Animals , Apoptosis/drug effects , Dependovirus , Dopamine/metabolism , Genetic Vectors , Integrases/administration & dosage , Integrases/genetics , Integrases/toxicity , Locomotion/physiology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neurons/drug effects , Neurons/metabolism
9.
Nature ; 485(7397): 242-5, 2012 Apr 04.
Article in English | MEDLINE | ID: mdl-22495311

ABSTRACT

Autism spectrum disorders (ASD) are believed to have genetic and environmental origins, yet in only a modest fraction of individuals can specific causes be identified. To identify further genetic risk factors, here we assess the role of de novo mutations in ASD by sequencing the exomes of ASD cases and their parents (n = 175 trios). Fewer than half of the cases (46.3%) carry a missense or nonsense de novo variant, and the overall rate of mutation is only modestly higher than the expected rate. In contrast, the proteins encoded by genes that harboured de novo missense or nonsense mutations showed a higher degree of connectivity among themselves and to previous ASD genes as indexed by protein-protein interaction screens. The small increase in the rate of de novo events, when taken together with the protein interaction results, are consistent with an important but limited role for de novo point mutations in ASD, similar to that documented for de novo copy number variants. Genetic models incorporating these data indicate that most of the observed de novo events are unconnected to ASD; those that do confer risk are distributed across many genes and are incompletely penetrant (that is, not necessarily sufficient for disease). Our results support polygenic models in which spontaneous coding mutations in any of a large number of genes increases risk by 5- to 20-fold. Despite the challenge posed by such models, results from de novo events and a large parallel case-control study provide strong evidence in favour of CHD8 and KATNAL2 as genuine autism risk factors.


Subject(s)
Autistic Disorder/genetics , DNA-Binding Proteins/genetics , Exons/genetics , Genetic Predisposition to Disease/genetics , Mutation/genetics , Transcription Factors/genetics , Case-Control Studies , Exome/genetics , Family Health , Humans , Models, Genetic , Multifactorial Inheritance/genetics , Phenotype , Poisson Distribution , Protein Interaction Maps
10.
PLoS Genet ; 9(6): e1003523, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23754953

ABSTRACT

Autism Spectrum Disorders (ASD) are highly heritable and characterised by impairments in social interaction and communication, and restricted and repetitive behaviours. Considering four sets of de novo copy number variants (CNVs) identified in 181 individuals with autism and exploiting mouse functional genomics and known protein-protein interactions, we identified a large and significantly interconnected interaction network. This network contains 187 genes affected by CNVs drawn from 45% of the patients we considered and 22 genes previously implicated in ASD, of which 192 form a single interconnected cluster. On average, those patients with copy number changed genes from this network possess changes in 3 network genes, suggesting that epistasis mediated through the network is extensive. Correspondingly, genes that are highly connected within the network, and thus whose copy number change is predicted by the network to be more phenotypically consequential, are significantly enriched among patients that possess only a single ASD-associated network copy number changed gene (p = 0.002). Strikingly, deleted or disrupted genes from the network are significantly enriched in GO-annotated positive regulators (2.3-fold enrichment, corrected p = 2×10(-5)), whereas duplicated genes are significantly enriched in GO-annotated negative regulators (2.2-fold enrichment, corrected p = 0.005). The direction of copy change is highly informative in the context of the network, providing the means through which perturbations arising from distinct deletions or duplications can yield a common outcome. These findings reveal an extensive ASD-associated molecular network, whose topology indicates ASD-relevant mutational deleteriousness and that mechanistically details how convergent aetiologies can result extensively from CNVs affecting pathways causally implicated in ASD.


Subject(s)
Child Development Disorders, Pervasive/genetics , Gene Dosage , Gene Regulatory Networks , Protein Interaction Maps/genetics , Animals , Child , Gene Deletion , Gene Duplication , Genetic Predisposition to Disease , Genome, Human , Humans , Mice
11.
Nat Genet ; 39(1): 25-7, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17173049

ABSTRACT

SHANK3 (also known as ProSAP2) regulates the structural organization of dendritic spines and is a binding partner of neuroligins; genes encoding neuroligins are mutated in autism and Asperger syndrome. Here, we report that a mutation of a single copy of SHANK3 on chromosome 22q13 can result in language and/or social communication disorders. These mutations concern only a small number of individuals, but they shed light on one gene dosage-sensitive synaptic pathway that is involved in autism spectrum disorders.


Subject(s)
Autistic Disorder/genetics , Carrier Proteins/genetics , Base Sequence , DNA Mutational Analysis , Female , Genetic Testing , Humans , In Situ Hybridization, Fluorescence , Male , Molecular Sequence Data , Mutation , Nerve Tissue Proteins , Pedigree
12.
Nat Genet ; 39(3): 319-28, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17322880

ABSTRACT

Autism spectrum disorders (ASDs) are common, heritable neurodevelopmental conditions. The genetic architecture of ASDs is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASDs by using Affymetrix 10K SNP arrays and 1,181 [corrected] families with at least two affected individuals, performing the largest linkage scan to date while also analyzing copy number variation in these families. Linkage and copy number variation analyses implicate chromosome 11p12-p13 and neurexins, respectively, among other candidate loci. Neurexins team with previously implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for contributing to ASDs.


Subject(s)
Autistic Disorder/genetics , Chromosome Aberrations , Chromosome Mapping , Genetic Linkage , Genetic Predisposition to Disease , Genetic Testing/methods , Autistic Disorder/diagnosis , Family , Female , Genetic Variation , Humans , Lod Score , Male , Risk Factors
13.
Am J Med Genet B Neuropsychiatr Genet ; 171B(3): 377-82, 2016 04.
Article in English | MEDLINE | ID: mdl-26978485

ABSTRACT

The proline dehydrogenase (PRODH) gene maps to 22q11.2 in the region deleted in the velo-cardio-facial syndrome (VCFS). A moderate to severe reduction (>50%) in PRODH activity resulting from recessive deletions and/or missense mutations has been shown to cause type 1 hyperprolinemia (HPI). Autistic features have been reported as a common clinical manifestation of HPI. Here we studied the frequency of a recurrent small 22q11.2 deletion encompassing PRODH and the neighboring DGCR6 gene in three case-control studies, one comprising HPI patients (n = 83), and the other two comprising autism spectrum disorder (ASD) patients (total of n = 2800), analyzed with high-resolution microarrays. We found that the PRODH deletion is a strong risk factor for HPI (OR = 50.7; 95%CI = 7.5-2147) but not for ASD (P = 0.4, OR = 0.6-3.3). This result indicates either that the suggested association between ASD and HPI is spurious and results from a bias leading to the preferential inclusion of patients with autistic features in HPI series, or that HPI is present in only a very small subset of ASD patients. In this latter case, a very large sample size would be required to detect an association between the PRODH deletion and ASD in a case-control study.


Subject(s)
Amino Acid Metabolism, Inborn Errors/genetics , Autism Spectrum Disorder/genetics , Chromosomes, Human, Pair 22/genetics , Extracellular Matrix Proteins/genetics , Gene Deletion , Genetic Predisposition to Disease , Proline Oxidase/genetics , Adult , Child , Child, Preschool , Cohort Studies , Female , Humans , Male , Nuclear Proteins , Risk Factors
14.
Proc Natl Acad Sci U S A ; 109(21): 7974-81, 2012 May 22.
Article in English | MEDLINE | ID: mdl-22566635

ABSTRACT

We recently reported a deletion of exon 2 of the trimethyllysine hydroxylase epsilon (TMLHE) gene in a proband with autism. TMLHE maps to the X chromosome and encodes the first enzyme in carnitine biosynthesis, 6-N-trimethyllysine dioxygenase. Deletion of exon 2 of TMLHE causes enzyme deficiency, resulting in increased substrate concentration (6-N-trimethyllysine) and decreased product levels (3-hydroxy-6-N-trimethyllysine and γ-butyrobetaine) in plasma and urine. TMLHE deficiency is common in control males (24 in 8,787 or 1 in 366) and was not significantly increased in frequency in probands from simplex autism families (9 in 2,904 or 1 in 323). However, it was 2.82-fold more frequent in probands from male-male multiplex autism families compared with controls (7 in 909 or 1 in 130; P = 0.023). Additionally, six of seven autistic male siblings of probands in male-male multiplex families had the deletion, suggesting that TMLHE deficiency is a risk factor for autism (metaanalysis Z-score = 2.90 and P = 0.0037), although with low penetrance (2-4%). These data suggest that dysregulation of carnitine metabolism may be important in nondysmorphic autism; that abnormalities of carnitine intake, loss, transport, or synthesis may be important in a larger fraction of nondysmorphic autism cases; and that the carnitine pathway may provide a novel target for therapy or prevention of autism.


Subject(s)
Autistic Disorder , Carnitine/deficiency , Chromosomes, Human, X/genetics , Genes, X-Linked/genetics , Metabolism, Inborn Errors , Mixed Function Oxygenases/genetics , Autistic Disorder/epidemiology , Autistic Disorder/genetics , Autistic Disorder/metabolism , Carnitine/biosynthesis , Cognition/physiology , Exons/genetics , Gene Deletion , Humans , Male , Metabolism, Inborn Errors/epidemiology , Metabolism, Inborn Errors/genetics , Metabolism, Inborn Errors/metabolism , Mixed Function Oxygenases/blood , Mixed Function Oxygenases/urine , Penetrance , Risk Factors , Siblings
15.
PLoS Genet ; 8(2): e1002521, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22346768

ABSTRACT

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23-4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11-q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the "multiple hit model" for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.


Subject(s)
Child Development Disorders, Pervasive/genetics , Nerve Tissue Proteins/genetics , Sequence Deletion/genetics , Synapses/genetics , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Adult , Alternative Splicing/genetics , Cell Line , Child , Child, Preschool , Female , Gene Dosage/genetics , Gene Expression Regulation , Humans , Male , Neurons/cytology , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA Splice Sites/genetics , Receptors, Nicotinic/genetics , Receptors, Nicotinic/metabolism , Synapses/pathology , Tissue Distribution , alpha7 Nicotinic Acetylcholine Receptor
16.
Rev Colomb Psiquiatr (Engl Ed) ; 53(1): 41-46, 2024.
Article in English, Spanish | MEDLINE | ID: mdl-38653661

ABSTRACT

BACKGROUND: Little is known about the incidence of delirium and its subtypes in patients admitted to different departments of university hospitals in Latin America. OBJECTIVE: To determine the incidence of delirium and the frequency of its subtypes, as well as its associated factors, in patients admitted to different departments of a university hospital in Bogotá, Colombia. METHODS: A cohort of patients over 18 years of age admitted to the internal medicine (IM), geriatrics (GU), general surgery (GSU), orthopaedics (OU) and intensive care unit (ICU) services of a university hospital was followed up between January and June 2018. To detect the presence of delirium, we used the CAM (Confusion Assessment Method) and the CAM-ICU if the patient had decreased communication skills. The delirium subtype was characterised using the RASS (Richmond Agitation and Sedation Scale). Patients were assessed on their admission date and then every two days until discharged from the hospital. Those in whom delirium was identified were referred for specialised intra-institutional interdisciplinary management. RESULTS: A total of 531 patients admitted during the period were assessed. The overall incidence of delirium was 12% (95% CI, 0.3-14.8). They represented 31.8% of patients in the GU, 15.6% in the ICU, 8.7% in IM, 5.1% in the OU, and 3.9% in the GSU. The most frequent clinical display was the mixed subtype, at 60.9%, followed by the normoactive subtype (34.4%) and the hypoactive subtype (4.7%). The factors most associated with delirium were age (adjusted RR = 1.07; 95% CI, 1.05-1.09), the presence of four or more comorbidities (adjusted RR = 2.04; 95% CI, 1.31-3.20), and being a patient in the ICU (adjusted RR = 2.02; 95% CI, 1.22-3.35). CONCLUSIONS: The incidence of delirium is heterogeneous in the different departments of the university hospital. The highest incidence occurred in patients that were admitted to the GU. The mixed subtype was the most frequent one, and the main associated factors were age, the presence of four or more comorbidities, and being an ICU patient.


Subject(s)
Delirium , Hospitals, University , Humans , Delirium/epidemiology , Delirium/diagnosis , Incidence , Male , Female , Middle Aged , Aged , Colombia/epidemiology , Aged, 80 and over , Adult , Intensive Care Units/statistics & numerical data , Cohort Studies , Hospitalization/statistics & numerical data , Risk Factors
17.
BMC Med Genet ; 14: 124, 2013 Dec 03.
Article in English | MEDLINE | ID: mdl-24299421

ABSTRACT

BACKGROUND: Widespread abnormalities in white matter development are frequently reported in cases of autism spectrum disorders (ASD) and could be involved in the disconnectivity suggested in these disorders. Homozygous mutations in the gene coding for fatty-acid 2-hydroxylase (FA2H), an enzyme involved in myelin synthesis, are associated with complex leukodystrophies, but little is known about the functional impact of heterozygous FA2H mutations. We hypothesized that rare deleterious heterozygous mutations of FA2H might constitute risk factors for ASD. METHODS: We searched deleterious mutations affecting FA2H, by genotyping 1256 independent patients with ASD genotyped using Genome Wide SNP arrays, and also by sequencing in independent set of 186 subjects with ASD and 353 controls. We then explored the impact of the identified mutations by measuring FA2H enzymatic activity and expression, in transfected COS7 cells. RESULTS: One heterozygous deletion within 16q22.3-q23.1 including FA2H was observed in two siblings who share symptoms of autism and severe cognitive impairment, axial T2-FLAIR weighted MRI posterior periventricular white matter lesions. Also, two rare non-synonymous mutations (R113W and R113Q) were reported. Although predictive models suggested that R113W should be a deleterious, we did not find that FA2H activity was affected by expression of the R113W mutation in cultured COS cells. CONCLUSIONS: While our results do not support a major role for FA2H coding variants in ASD, a screening of other genes related to myelin synthesis would allow us to better understand the role of non-neuronal elements in ASD susceptibility.


Subject(s)
Child Development Disorders, Pervasive/genetics , Mixed Function Oxygenases/genetics , Adolescent , Amino Acid Sequence , Animals , Brain/diagnostic imaging , COS Cells , Child Development Disorders, Pervasive/pathology , Child, Preschool , Chlorocebus aethiops , Cohort Studies , Gene Deletion , Genotype , Heterozygote , Humans , Magnetic Resonance Imaging , Male , Mixed Function Oxygenases/metabolism , Molecular Sequence Data , Pedigree , Polymorphism, Single Nucleotide , Radiography , Risk Factors , Sequence Analysis, DNA
18.
Nat Genet ; 34(1): 27-9, 2003 May.
Article in English | MEDLINE | ID: mdl-12669065

ABSTRACT

Many studies have supported a genetic etiology for autism. Here we report mutations in two X-linked genes encoding neuroligins NLGN3 and NLGN4 in siblings with autism-spectrum disorders. These mutations affect cell-adhesion molecules localized at the synapse and suggest that a defect of synaptogenesis may predispose to autism.


Subject(s)
Autistic Disorder/genetics , Carrier Proteins/genetics , Chromosomes, Human, X/genetics , Membrane Proteins/genetics , Mutation , Nerve Tissue Proteins/genetics , Amino Acid Sequence , Autistic Disorder/metabolism , Base Sequence , Brain/metabolism , Cell Adhesion Molecules, Neuronal , DNA, Complementary/genetics , Female , Gene Expression Profiling , Genetic Linkage , Humans , Male , Molecular Sequence Data , Pedigree , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sequence Homology, Amino Acid
19.
Transl Psychiatry ; 13(1): 302, 2023 09 29.
Article in English | MEDLINE | ID: mdl-37775532

ABSTRACT

Selective serotonin reuptake inhibitors (SSRI) are common first-line treatments for major depression. However, a significant number of depressed patients do not respond adequately to these pharmacological treatments. In the present preclinical study, we demonstrate that organic cation transporter 2 (OCT2), an atypical monoamine transporter, contributes to the effects of SSRI by regulating the routing of the essential amino acid tryptophan to the brain. Contrarily to wild-type mice, OCT2-invalidated mice failed to respond to prolonged fluoxetine treatment in a chronic depression model induced by corticosterone exposure recapitulating core symptoms of depression, i.e., anhedonia, social withdrawal, anxiety, and memory impairment. After corticosterone and fluoxetine treatment, the levels of tryptophan and its metabolites serotonin and kynurenine were decreased in the brain of OCT2 mutant mice compared to wild-type mice and reciprocally tryptophan and kynurenine levels were increased in mutants' plasma. OCT2 was detected by immunofluorescence in several structures at the blood-cerebrospinal fluid (CSF) or brain-CSF interface. Tryptophan supplementation during fluoxetine treatment increased brain concentrations of tryptophan and, more discreetly, of 5-HT in wild-type and OCT2 mutant mice. Importantly, tryptophan supplementation improved the sensitivity to fluoxetine treatment of OCT2 mutant mice, impacting chiefly anhedonia and short-term memory. Western blot analysis showed that glycogen synthase kinase-3ß (GSK3ß) and mammalian/mechanistic target of rapamycin (mTOR) intracellular signaling was impaired in OCT2 mutant mice brain after corticosterone and fluoxetine treatment and, conversely, tryptophan supplementation recruited selectively the mTOR protein complex 2. This study provides the first evidence of the physiological relevance of OCT2-mediated tryptophan transport, and its biological consequences on serotonin homeostasis in the brain and SSRI efficacy.


Subject(s)
Depressive Disorder, Major , Organic Cation Transporter 2 , Selective Serotonin Reuptake Inhibitors , Animals , Mice , Anhedonia , Antidepressive Agents/therapeutic use , Brain/metabolism , Corticosterone/pharmacology , Depressive Disorder, Major/drug therapy , Fluoxetine/pharmacology , Kynurenine/metabolism , Organic Cation Transporter 2/metabolism , Selective Serotonin Reuptake Inhibitors/pharmacology , Serotonin/metabolism , Tryptophan/metabolism
20.
Am J Med Genet C Semin Med Genet ; 160C(2): 130-42, 2012 May 15.
Article in English | MEDLINE | ID: mdl-22499558

ABSTRACT

Autism spectrum disorders (ASD) are a group of related neurodevelopmental disorders with significant combined prevalence (∼1%) and high heritability. Dozens of individually rare genes and loci associated with high-risk for ASD have been identified, which overlap extensively with genes for intellectual disability (ID). However, studies indicate that there may be hundreds of genes that remain to be identified. The advent of inexpensive massively parallel nucleotide sequencing can reveal the genetic underpinnings of heritable complex diseases, including ASD and ID. However, whole exome sequencing (WES) and whole genome sequencing (WGS) provides an embarrassment of riches, where many candidate variants emerge. It has been argued that genetic variation for ASD and ID will cluster in genes involved in distinct pathways and protein complexes. For this reason, computational methods that prioritize candidate genes based on additional functional information such as protein-protein interactions or association with specific canonical or empirical pathways, or other attributes, can be useful. In this study we applied several supervised learning approaches to prioritize ASD or ID disease gene candidates based on curated lists of known ASD and ID disease genes. We implemented two network-based classifiers and one attribute-based classifier to show that we can rank and classify known, and predict new, genes for these neurodevelopmental disorders. We also show that ID and ASD share common pathways that perturb an overlapping synaptic regulatory subnetwork. We also show that features relating to neuronal phenotypes in mouse knockouts can help in classifying neurodevelopmental genes. Our methods can be applied broadly to other diseases helping in prioritizing newly identified genetic variation that emerge from disease gene discovery based on WES and WGS.


Subject(s)
Child Development Disorders, Pervasive/genetics , Gene Regulatory Networks/genetics , Genetic Markers/genetics , Genetic Variation/genetics , Intellectual Disability/genetics , Signal Transduction , Child , Child Development Disorders, Pervasive/classification , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Intellectual Disability/classification , Phenotype
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