The severity of autism spectrum disorder (ASD) shows wide variations, though the reason remains unclear. Vitamin D (VitD) deficiency is considered a risk factor for ASD and its supplementation was reported to reduce symptom severity. Since VitD, either synthesized in the skin or absorbed from the food, is transported to the liver by the vitamin D binding protein (DBP), we have analyzed DBP genetic polymorphisms [rs7041 (A/C), rs4588 (G/T), and rs3755967 (C/T)] affecting DBP function [Case = 411; Control = 397], levels of plasma 25(OH)D and DBP [Case = 25; Control = 26], and DBP mRNA expression [Case = 74; Control = 44] in a group of Indo-Caucasoid ASD probands and neurotypical subjects.
View Article and Find Full Text PDFGlutamate (Glu) is important for memory and learning. Hence, Glu imbalance is speculated to affect autism spectrum disorder (ASD) pathophysiology. The action of Glu is mediated through receptors and we analyzed four metabotropic Glu receptors (mGluR/GRM) in Indo-Caucasoid families with ASD probands and controls.
View Article and Find Full Text PDFAttention deficit hyperactivity disorder (ADHD), a childhood-onset neurobehavioral disorder, often perturbs scholastic achievement and peer-relationship. The pivotal role of glutamate (Glu) in learning and memory indicated an influence of Glu in ADHD, leading to the exploration of Glu in different brain regions of ADHD subjects. We for the first time analyzed GluR genetic variations, Glu levels, as well as expression of Glu receptors (GluR) in the peripheral blood of eastern Indian ADHD probands to find out the relevance of Glu in ADHD prognosis.
View Article and Find Full Text PDFBackground: The reasons behind the cardinal symptoms of communication deficits and repetitive, stereotyped behaviors that characterize autism spectrum disorder (ASD) remain unknown. The dopamine (DA) system, which regulates motor activity, goal-directed behaviors, and reward function, is believed to play a crucial role in ASD, although the exact mechanism is still unclear. Investigations have shown an association of the dopamine receptor D4 (DRD4) with various neurobehavioral disorders.
View Article and Find Full Text PDFSurface proteins containing leucine-rich repeat (LRR) are essential for the formation of synapses. Therefore, proteins containing aberrant LRR regions are speculated to cause synaptic dysfunction, an abnormality often associated with Autism spectrum disorder (ASD). LRR transmembrane 3 (LRRTM3) genetic variants showed association with ASD in the Caucasoid probands.
View Article and Find Full Text PDFExecutive dysfunctions caused by structural and functional abnormalities of the prefrontal cortex were reported in patients with Attention deficit hyperactivity disorder (ADHD). Owing to a higher expression of the glutamate ionotropic receptor kainate type subunit 1 (GluK1), encoded by the GRIK1 gene, in brain regions responsible for learning and memory, we hypothesized that GRIK1 might have a role in ADHD. GRIK1 variants rs363504 and rs363538, affecting the receptor function, were analyzed by case-control and family-based methods to identify the association with ADHD.
View Article and Find Full Text PDFObjectives: Symptomatic remediation from attention deficit hyperactivity disorder (ADHD)-associated traits is achieved by treatment with methylphenidate (MPH)/atomoxetine (ATX). We have analyzed the association of functional variations, rs1065852, rs3892097, rs1135840, and rs1058164, with ADHD in the Indian subjects.
Methods: Subjects were recruited following the Diagnostic and Statistical Manual for Mental Disorders.
Background: The serotonin transporter (SERT), encoded by the solute carrier family 6 number 4 (SLC6A4) gene, controls serotonin (5-HT) availability and is essential for the regulation of behavioral traits. Two SLC6A4 genetic variants, 5-HTTLPR and STin2, were widely investigated in patients with various neurobehavioral disorders, including attention deficit hyperactivity disorder (ADHD).
Methods: We analyzed the association of the 5-HTTLPR (L/S) and STin2 (10/12) variants, plasma 5-HT, and 5-hydroxyindole acetic acid (5-HIAA), as well as SERT messenger RNA (mRNA) with ADHD in the eastern Indian subjects.
Altered signaling of the chief inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), has been speculated in the etiology of autism spectrum disorder (ASD). We have investigated the association of six GABA-receptor genetic variants and plasma GABA levels with ASD. Subjects were recruited based on the DSM, and CARS2-ST and ADI-R assessed disease severity.
View Article and Find Full Text PDFBackground: Impulsivity (Imp), being one of the cardinal symptoms of Attention Deficit Hyperactivity Disorder (ADHD), often leads to inappropriate responses to stimuli. Since the dopaminergic system is the primary target for pharmaceutical intervention in ADHD, we investigated the association between ADHD-related Imp and functional gene variants of the dopamine transporter (SLC6A3) and catechol-O-methyltransferase involved in dopamine clearance.
Methods And Results: Indo-Caucasoid families with ADHD probands (N = 217) were recruited based on the Diagnostic and Statistical Manual of Mental Disorders (DSM).
Imbalance in dopamine (DA) signaling is proposed to play a potential role in the etiology of Autism spectrum disorder (ASD) since, as a neuromodulator, DA regulates executive function, motor activity, social peering, attention as well as perception and subjects with ASD often exhibit deficit in these traits. Level of DA in the synaptic cleft is maintained by dopamine transporter (DAT) and hence, to identify the role of DAT in ASD, we have analyzed four functional genetic variants, rs28363170, rs3836790, rs2652511, rs27072, in nuclear families with ASD probands. Subjects were diagnosed based on Diagnostic and Statistical Manual for Mental Disorders and trait severity was assessed by Childhood Autism Rating Scale 2-Standard test.
View Article and Find Full Text PDFPrimary symptoms of Attention Deficit Hyperactivity Disorder (ADHD) are age inappropriate inattention, hyperactivity and impulsivity. Caucasoid individuals showed increased susceptibility to ADHD and disruptive behaviour in presence of Adhesion G-protein-coupled receptor L3 (ADGRL3) gene variants. We investigated ADGRL3 rs1868790, rs6551665, rs2345039 in Indo-Caucasoid families with ADHD probands (N = 249) and controls (N = 350).
View Article and Find Full Text PDFAlteration in gamma aminobutyric acid (GABA), the principal inhibitory neurotransmitter, is speculated to be a potential risk factor for Autism Spectrum Disorder (ASD) due to an altered expression in the brain. Sensory, social, and emotional deficits of subjects with ASD were reported to be caused by an imbalance between excitatory and inhibitory neurotransmission as well as GABAergic dysfunction caused by inadequate receptor function. We for the first time studied association between ASD and a missense coding variant rs3810651 (I478F) in the GABRQ gene, encoding for one of the subunits of GABA receptors.
View Article and Find Full Text PDFDown syndrome (DS) is associated with trisomy of the 21 chromosome in more than 95% cases. The extra chromosome mostly derives due to abnormal chromosomal segregation, i.e.
View Article and Find Full Text PDFOrganizational inefficiency and inattention are speculated to be the reason for executive deficit (ED) of ADHD probands. Even with average IQ, probands often perform poorly due to higher inattention. Pharmacotherapy, cognitive behavioural therapy, and counselling provide only symptomatic relief.
View Article and Find Full Text PDFProg Neuropsychopharmacol Biol Psychiatry
June 2018
An etiologically complex disorder, Attention Deficit Hyperactivity Disorder (ADHD), is often associated with various levels of cognitive deficit. Folate/vitamin B is crucial for numerous biochemical pathways including neural stem cell proliferation and differentiation, regulation of gene expression, neurotransmitter synthesis, myelin synthesis and repair, etc. and a scarcity has often been linked to cognitive deficit.
View Article and Find Full Text PDFCortical neuronal migration and formation of filamentous actin cytoskeleton, needed for development, normal cell growth and differentiation, are regulated by the cyclin-dependent kinase 5 (Cdk5). Attention deficit hyperactivity disorder (ADHD) is associated with delayed maturation of the brain and hence we hypothesized that cdk5 may have a role in ADHD. Eight functional CDK5 gene variants were analyzed in 848 Indo-Caucasoid individuals including 217 families with ADHD probands and 250 healthy volunteers.
View Article and Find Full Text PDFWe investigated role of the folate-homocysteine metabolic pathway in the etiology of attention-deficit hyperactivity disorder (ADHD) due to its importance in maintaining DNA integrity as well as neurotransmission. Functional gene variants in MTR (rs1805087), CBS (rs5742905), MTHFR (rs1801133 &rs1801131), MTHFD (rs2236225), RFC1 (rs1051266), plasma vitamin B12, folate and homocysteine were analyzed. rs1805087 'A' showed strong association with ADHD.
View Article and Find Full Text PDFBackground: Chronic lead (Pb(2+)) exposure leads to the reduced lifespan of erythrocytes. Oxidative stress and K(+) loss accelerate Fas translocation into lipid raft microdomains inducing Fas mediated death signaling in these erythrocytes. Pathophysiological-based therapeutic strategies to combat against erythrocyte death were evaluated using garlic-derived organosulfur compounds like diallyl disulfide (DADS), S allyl cysteine (SAC) and imidazole based Gardos channel inhibitor clotrimazole (CLT).
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