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1.
J Psychiatr Res ; 145: 92-101, 2021 Nov 29.
Article in English | MEDLINE | ID: mdl-34883412

ABSTRACT

Several traits related to positive and negative affect show a high genetic as well as phenotypic correlation with well-being in humans, and are therefore collectively termed as "Well-being spectrum". Genome-Wide Association studies (GWA studies) on "well-being measurement" have led to identification of several genomic variants (Single Nucleotide Variants - SNVs), but very little has been explained with respect to their functionality and mode of alteration of well-being. Utilizing a pool of 1258 GWA studies based SNVs on "well-being measurement", we prioritized the SNVs and tried to annotate well-being related functionality through several bioinformatic tools to predict whether a protein sequence variation affects protein function, as well as experimentally validated datasets available in ENCODE based web-tools namely rSNPBase, RegulomeDB, Haploreg, along with GTEx Portal and STRING based protein interaction networks. Prioritization yielded three key SNVs; rs3781627-A, rs13072536-T and 5877-C potentially regulating three genes, PSMC3, ITIH4 and SERPINC1, respectively. Interestingly, the genes showed well clustered protein-protein interaction (maximum combined confidence score >0.4) with other well-being candidate genes, namely TNF and CRP genes suggesting their important role in modulation of well-being. PSMC3 and ITIH4 genes are also involved in driving acute phase responses signifying a probable cross-talk between well-being and psychoneuroimmunological system. To best of our knowledge this study is the first of its kind where the well-being associated GWA studies-SNVs were prioritized and functionally annotated, majorly based on functional data available in public domain, which revealed PSMC3, ITIH4 and SERPINC1 genes as probable candidates in regulation of well-being spectrum.

2.
Curr Med Chem ; 25(36): 4693-4717, 2018.
Article in English | MEDLINE | ID: mdl-28393691

ABSTRACT

Secondary metabolites from numerous plant sources have been developed as anti- cancer reagents and compounds such as resveratrol, podophyllotoxin and zerumbone are of particular importance in this regard. Since their de novo chemical synthesis is both arduous and commercially expensive, there has been an impetus to develop viable, biotechnological methods of production. Accordingly, this review focuses on the recent developments in the field, highlighting the use of micropropagation, cell suspension cultures, callus cultures, hairy root cultures, recombinant microbes and genetically modified higher plants. Optimization of media and culture conditions, precursor feeding, immobilization and the use of chemical or physical elicitation in various protocols has led to an increase in resveratrol and podophyllotoxin production. Heterologous gene transformation of higher plants with stilbene synthase derived from Arachis hypogaea or Vitis vinifera lead to resveratrol production with the concomitant increase in resistance to plant pathogens. Interestingly, genetic transformation of Podophyllum hexandrum and Linum flavum with Agrobacterium rhizogenes resulted in Ri-T-DNA gene(s)-mediated enhancement of podophyllotoxin production. Zerumbone yields from tissue cultured plantlets or from suspension cultures are generally low and these methods require further optimization. In microbes lacking the native resveratrol or zerumbone biosynthesis pathway, metabolic engineering required not only the introduction of several genes of the pathway, but also precursor feeding and optimization of gene expression to increase their production. Data pertaining to safety and toxicity testing are needed prior to use of these sources of anti-cancer compounds in therapy.


Subject(s)
Antineoplastic Agents/chemical synthesis , Biotechnology/methods , Podophyllotoxin/biosynthesis , Resveratrol/chemical synthesis , Sesquiterpenes/chemical synthesis , Animals , Bacteria/genetics , Cells, Cultured , Humans , Metabolic Engineering/methods , Plants/genetics
3.
Recent Pat Biotechnol ; 11(2): 85-100, 2017.
Article in English | MEDLINE | ID: mdl-28137207

ABSTRACT

BACKGROUND: Resveratrol, taxol, podophyllotoxin, withanolides and their derivatives find applications in anti-cancer therapy. They are plant-derived compounds whose chemical structures and synthesis limit their natural availability and restrict a large-scale industrial production. Hence, their production by various biotechnological approaches may hold promise for a continuous and reliable mode of supply. OBJECTIVE: We review process and product patents in this regard. METHODS: Accordingly, we provide a general outline to search the freely accessible WIPO, EPO, USPTO and Cambia databases with several keywords and patent codes. We have tabulated both granted and filed patents from the said databases. RESULTS AND CONCLUSION: We retrieved ~40 patents from these databases. Novel biotechnological processes for production of these anticancer compounds include Agrobacterium rhizogenes-mediated hairy root culture, suspension culture, cell culture with elicitors, use of recombinant microorganisms, and bioreactors among others. The results are indicative of being both database-specific as well as queryspecific. A ten-year search window yielded 33 patents. The utility of the search strategy is discussed in the light of biotechnological developments in the field. Those who examine patent literature using similar search strategies may complement their knowledge obtained from perusal of mainstream journal resources.


Subject(s)
Neoplasms/drug therapy , Paclitaxel/therapeutic use , Podophyllotoxin/therapeutic use , Stilbenes/therapeutic use , Withanolides/therapeutic use , Humans , Neoplasms/metabolism , Neoplasms/pathology , Patents as Topic , Resveratrol
4.
Neurochem Int ; 82: 52-68, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25684070

ABSTRACT

The onset of attention-deficit-hyperactivity-disorder (ADHD) in childhood is characterized by developmentally inappropriate levels of hyperactivity, impulsivity and inattention. A chronic deficit of serotonin (5-HT) at the synapse may trigger symptoms of ADHD. This review focuses on neuro-anatomical, experimental and clinical pharmacological evidence, as well as the genetic underpinnings of serotoninergic involvement in the etiology of ADHD. Neuro-anatomical investigations suggest that serotonin through the orbitofrontal-striatal circuitry may regulate behavioral domains of hyperactivity and impulsivity in ADHD. Studies from animal models of ADHD indicate intimate interplay between 5-HT and dopaminergic neurotransmission. Selective serotonin re-uptake inhibitors, as also non-stimulant drugs acting on the 5-HT system are, however, clinically effective. They impart less severe side effects in patients with no risk of addiction. Oral administration of l-tryptophan, the amino acid precursor of 5-HT, significantly alleviates ADHD symptoms. Given the multifactorial nature of ADHD, candidate gene and genome-wide association studies have suggested that serotoninergic gene variants are associated with increased risk of ADHD with each locus individually exerting a modest effect on overall risk.


Subject(s)
Attention Deficit Disorder with Hyperactivity/genetics , Serotonin/deficiency , Adolescent , Animals , Animals, Newborn , Attention Deficit Disorder with Hyperactivity/drug therapy , Attention Deficit Disorder with Hyperactivity/physiopathology , Central Nervous System Stimulants/therapeutic use , Child , Child, Preschool , Corpus Striatum/physiopathology , Disease Models, Animal , Dopamine/physiology , Gene-Environment Interaction , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Inhibition, Psychological , Mice, Knockout , Multifactorial Inheritance , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/physiology , Neurotransmitter Transport Proteins/deficiency , Neurotransmitter Transport Proteins/genetics , Oxidopamine/toxicity , Prefrontal Cortex/drug effects , Prefrontal Cortex/physiopathology , Rats, Inbred SHR , Rats, Inbred WKY , Receptor, Serotonin, 5-HT1B/deficiency , Serotonin/physiology , Selective Serotonin Reuptake Inhibitors/pharmacology , Selective Serotonin Reuptake Inhibitors/therapeutic use , Tryptophan/deficiency , Tryptophan/therapeutic use
5.
Indian J Biochem Biophys ; 50(5): 345-56, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24772956

ABSTRACT

Adenosine deaminase deficiency accounts for approximately 15-20% of severe combined immunodeficiency in humans. The gene for adenosine deaminase is located on chromosome 20q12-q13.11 and codes for an aminohydrolase that catalyzes the deamination of adenosine and deoxyadenosine to inosine and deoxyinosine, respectively. Absence of the enzyme causes a build-up of the substrates in addition to excess deoxyadenosine triphosphate, thereby compromising the regenerative capacity of the immune system. Due to underlying allelic heterogeneity, the disorder manifests as a spectrum, ranging from neonatal onset severe combined immunodeficiency to apparently normal partial adenosine deaminase deficiency. Tandem mass spectrometry coupled with high efficiency separation systems enables postnatal diagnosis of the disorder, while prenatal diagnosis relies on assaying enzyme activity in cultured amniotic fibroblasts or chorionic villi sampling. Screening of adenosine deaminase deficiency for relatives-at-risk may reduce costs of treatment and ensure timely medical intervention as applicable. This article reviews the genetic, biochemical and clinical aspects of adenosine deaminase deficiency.


Subject(s)
Adenosine Deaminase/deficiency , Metabolic Diseases/genetics , Metabolic Diseases/metabolism , Genetic Heterogeneity , Humans , Metabolic Diseases/diagnosis , Metabolic Diseases/therapy
6.
Indian J Hum Genet ; 18(2): 204-16, 2012 May.
Article in English | MEDLINE | ID: mdl-23162297

ABSTRACT

INTRODUCTION: Down syndrome (DS), the leading genetic cause of mental retardation, stems from non-disjunction of chromosome 21. AIM: Our aim was to discern non-disjunction in DS patients by genotyping GluK1-(AGAT)(n) and D21S2055-(GATA)(n) microsatellites on chromosome 21 using a family-based study design. MATERIALS AND METHODS: We have used a PCR and automated DNA sequencing followed by appropriate statistical analysis of genotype data for the present study RESULTS AND DISCUSSION: We show that a high power of discrimination and a low probability of matching indicate that both markers may be used to distinguish between two unrelated individuals. That the D21S2055-(GATA)(n) allele distribution is evenly balanced, is indicated by a high power of exclusion [PE=0.280]. The estimated values of observed heterozygosity and polymorphism information content reveal that relative to GluK1-(AGAT)(n)[H(obs)=0.286], the D21S2055- (GATA)(n)[H(obs)=0.791] marker, is more informative. Though allele frequencies for both polymorphisms do not conform to Hardy-Weinberg equilibrium proportions, we were able to discern the parental origin of non-disjunction and also garnered evidence for triallelic (1:1:1) inheritance. The estimated proportion of meiosis-I to meiosis-II errors is 2:1 in maternal and 4:1 in paternal cases for GluK1-(AGAT)(n), whereas for D21S2055-(GATA)(n), the ratio is 2:1 in both maternal and paternal cases. Results underscore a need to systematically evaluate additional chromosome 21-specific markers in the context of non-disjunction DS.

7.
Genet Test Mol Biomarkers ; 16(10): 1226-35, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22931243

ABSTRACT

AIM: We wished to identify markers associated with allelic nondisjunction in nuclear families with Down syndrome (DS) offspring. Since the GRIK1 and GARS-AIRS-GART genes, mapping to chromosome 21q22.1, may be informative in this regard, we genotyped four single-nucleotide polymorphisms [30952599(A/G) rs363484; 30924733(A/G) rs363506; 34901423(A/G) rs2834235; 34877070(A/G) rs7283354] present in these genes using the SNaPshot(™) assay protocol. RESULTS: We have reported 30952599(A/G)-rs363484 to be monomorphic in our sample population. Genotyping revealed 35/65 families to be informative for 34877070(A/G)-rs7283354 (GARS-AIRS-GART), whereas only 25/65 and 11/65 are informative for 34901423(A/G)-rs2834235 (GARS-AIRS-GART) and 30924733(A/G)-rs363506 (GRIK1) polymorphisms, respectively. The parent- and stage-of-origin of nondisjunction could be traced in 48/65 families using at least one polymorphic marker. A single trio provided internal validation for assignment of the parent- and stage-of-origin of nondisjunction whereby the nondisjoining alleles were independently identified as G-rs363506, G-rs2834235, and G-rs7283354, respectively. An enhanced ratio of meiosis-I to meiosis-II errors during maternal or paternal meioses accounts for allelic nondisjunction. CONCLUSIONS: The SNaPshot assay is quantitative and permits multiplexing for detection of allelic nondisjunction. Inclusion of additional informative chromosome 21-specific markers may aid rapid aneuploidy detection, screening, and prenatal counseling of parents at risk of having babies with DS.


Subject(s)
Carbon-Nitrogen Ligases/genetics , Down Syndrome/genetics , Nondisjunction, Genetic , Phosphoribosylglycinamide Formyltransferase/genetics , Polymorphism, Single Nucleotide , Receptors, Kainic Acid/genetics , Alleles , Chromosomes, Human, Pair 21/genetics , Female , Genotype , Humans , Male
9.
Indian J Clin Biochem ; 27(1): 46-51, 2012 Jan.
Article in English | MEDLINE | ID: mdl-23277712

ABSTRACT

UNLABELLED: GARS-AIRS-GART is crucial in studies of Down syndrome (DS)-related mental retardation due to its chromosomal location (21q22.1), involvement in de novo purine biosynthesis and over-expression in fetal DS brain postmortem samples. GARS-AIRS-GART regions important for structure-function were screened for mutations that might alter protein levels in DS patients. Mutation screening relied on multiplex/singleplex PCR-based amplification of genomic targets followed by amplicon size determination/fingerprinting. Serum protein samples were resolved by SDS-PAGE and immunoblotted with a GARS-AIRS-GART monoclonal antibody. No variation in amplicon size/fingerprints was observed in regions encoding the ATP-binding, active site residues of GARS, the structurally important glycine-rich loops of AIRS, substrate-binding, flexible and folate-binding loops of GART or the poly-adenylation signal sequences. The de novo occurrence or inheritance of large insertion/deletion/rearrangement-type mutations is therefore excluded. Immunoblots show presence of GARS-AIRS-GART protein in all patient samples, with no change in expression levels with respect to either sex or developmental age. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12291-011-0183-6) contains supplementary material, which is available to authorized users.

10.
Dis Markers ; 27(2): 45-54, 2009.
Article in English | MEDLINE | ID: mdl-19893199

ABSTRACT

Mechanisms underlying Down syndrome (DS)-related mental retardation (MR) remain poorly understood. In trisomic offspring, non-disjunction may result in the reduction to homozygosity of a susceptibility allele inherited from a heterozygous parent. Accordingly, we sought evidence for allelic non-disjunction in the GluK1 gene that encodes the critical kainite-binding glutamate receptor subunit-5, maps to chromosome 21q22.1 in the DS critical region and is expressed in brain regions responsible for learning and memory. Three polymorphisms of GluK1 [522(A/C) rs363538; 1173(C/T) rs363430 and 2705(T/C) rs363504] were genotyped in 86 DS patient families by means of PCR-coupled RFLP assays and evaluated with respect to allele frequency, heterozygosity, linkage disequilibrium, stage and parental origin of allelic non-disjunction. We report that the distribution of allele frequencies is in Hardy-Weinberg equilibrium. Moderate heterozygosity (0.339) and a major allele frequency of 0.78 render the 1173(C/T) marker informative. Pair-wise comparisons reveal that 522(A/C)-1173(C/T) [chi;{2} = 31.2, df = 1, p = 0.0001; D' = 0.42] and 1173(C/T)-2705(T/C) [chi;{2} = 18.3, df = 1, p = 0.0001; D' = 0.34] are in significant linkage disequilibrium of weak magnitude. The estimated ratio of meiosis-I to meiosis-II errors arising from allelic non-disjunction of 1173(C/T) is 4:1 in maternal cases and 2:1 in paternal cases. Studies including additional markers and patient samples are warranted to further substantiate present findings.


Subject(s)
Down Syndrome/genetics , Polymorphism, Genetic/genetics , Receptors, Kainic Acid/genetics , Child , Chromosomes, Human, Pair 21/genetics , Female , Gene Frequency , Humans , Linkage Disequilibrium , Male , Meiosis , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length
11.
Neurosci Lett ; 454(3): 244-8, 2009 May 01.
Article in English | MEDLINE | ID: mdl-19429092

ABSTRACT

PURPOSE OF THE STUDY: The G482T and G689T polymorphisms in the 3'-UTR of serotonin transporter (SLC6A4) are implicated in translational regulation and allelic variants may mediate susceptibility to attention-deficit-hyperactivity disorder (ADHD). Accordingly, we examined influence of allelic variation on stable secondary structure formation and on seed sequences necessary for microRNA-binding. Furthermore, 90 ADHD cases from India were genotyped for these markers and tested for association with ADHD. METHODS: The Mfold software was used for secondary structure predictions and miRNA-binding sequences were obtained from the PicTar database. Using a family-based study design we assessed genetic association by means of the haplotype-based haplotype relative risk (HHRR) and transmission disequilibrium test (TDT) statistics. With respect to G689T, previously published TDT data were included in pooled analysis. RESULT: Secondary structure analysis reveals that G482, U482, G689 and U689 conformers are energetically similar. Unlike G482, the U482 change maps within a loop and this conformer differs in free energy by approximately 4.4kcal/mol. While G482T is proximal to various miRNA-binding sequences, it is not part of the seed sequence for any of them. Thus, G482T and G689T polymorphisms do not regulate SLC6A4 translation in cis. From the HHRR (chi(2)=0.860, p=0.353; R.R.=1.11; 95% C.I.=0.89-1.65 for G482T; chi(2)=0.902, p=0.342; R.R.=1.17; 95% C.I.=0.83-1.32 for G689T), TDT (chi(2)=1.33, p=0.25; O.R.=1.35; 95% C.I.=0.94-1.94 for G482T; chi(2)=1.45, p=0.23; O.R.=1.44; 95% C.I.=0.94-2.22 for G689T) and pooled TDT (chi(2)=0.52, p=0.47; O.R.=1.05; 95% C.I.=0.96-1.15) statistics we infer that these polymorphisms are not associated with risk of ADHD.


Subject(s)
Attention Deficit Disorder with Hyperactivity/genetics , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Serotonin Plasma Membrane Transport Proteins/genetics , 3' Untranslated Regions/genetics , Base Sequence , Child , Female , Gene Frequency , Humans , Male , Molecular Sequence Data , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Protein Biosynthesis , Protein Structure, Secondary , Risk Factors , Serotonin Plasma Membrane Transport Proteins/chemistry
12.
Mol Biotechnol ; 42(3): 306-19, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19301155

ABSTRACT

Human GARS-AIRS-GART encodes a fused tri-functional enzyme protein involved in de novo purine biosynthesis, aberrant function being implicated in Down syndrome and Leukemia. We performed phylogenetic analysis to discern evolutionary relationships and in silico characterization to identify elements potentially important for gene regulation. We report that murine, bovine and chimpanzee sequences are the nearest neighbors of human GARS-AIRS-GART and that endo-duplication of the AIRS protein is restricted to insect orthologs. Convergent evolution of mono-functional bacterial orthologs to bi-functional, partly fused, yeast orthologs is observed from the rooted-NJ tree topology that bears bootstrap values exceeding 9000 in majority of the nodes. Sequence alignments reveal that introns 11-15 of human GARS-AIRS-GART are conserved among vertebrates. An inverse correlation is observed between intron size and intron density without bias for intron position. The generation time of organisms is independent of intron density. Human, bovine and murine sequences possess similar GC content with CpG islands in promoter regions. The long isoforms of cow and chicken transcripts and short isoforms of human, bovine and murine mRNA form energetically stable stem-like structures in the 3'-UTR and may regulate translational stability of GARS-AIRS-GART transcripts. Glycine-rich loops important for enzyme structure and ATP-, folate-binding residues are partially conserved.


Subject(s)
Carbon-Nitrogen Ligases/genetics , Phosphoribosylglycinamide Formyltransferase/genetics , Amino Acid Sequence , Animals , Base Composition , Carbon-Nitrogen Ligases/metabolism , Cluster Analysis , Computer Simulation , CpG Islands , Gene Expression Regulation , Humans , Models, Genetic , Molecular Sequence Data , Phosphoribosylglycinamide Formyltransferase/metabolism , Phylogeny , Sequence Alignment , Statistics, Nonparametric , Untranslated Regions
13.
Cell Mol Neurobiol ; 27(8): 1117-26, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17902044

ABSTRACT

(1) GARS-AIRS-GART is an important candidate gene in studies of Down syndrome (DS)-related Alzheimer's disease (AD), due to its chromosomal localization (21q22.1) in the Down syndrome critical region, involvement in de novo purine biosynthesis, and over-expression in DS brain. The aim of this study was to identify factor(s) likely to enhance transcription of GARS-AIRS-GART in DS-related AD. (2) Based on a bio-informatics approach, the PromoterInspector, Promoter Scan II, and EBI toolbox CpG plot software programs were used to identify GARS-AIRS-GART sequences important for gene transcription. Transcription factor binding motifs within these regions were mapped with the help of the MatInspector and TFSEARCH programs. Factors implicated in neurodevelopment or neurodegeneration were the focus of attention, and mining of human (T1Dbase) and murine (GNF) expression databases revealed information on the regional distribution of these factors and their relative abundance vis-a-vis GARS-AIRS-GART. (3) The Leader-binding protein 1-c (LBP-1c/CP2/LSF) emerged as a promising candidate from these studies, as MatInspector and TFSEARCH analyses revealed a total of four CP2 binding sites with potential for functional interaction(s) within the promoter and CpG islands of GARS-AIRS-GART. Furthermore, two of these sites harbor sequences for methylation-sensitive restriction enzymes, which suggest that methylation status may, in part, regulate CP2-mediated transcription of GARS-AIRS-GART. A search of T1Dbase and GNF expression databases reveals co-expression of CP2 and GARS-AIRS-GART in brain regions relevant to DS-related AD. (4) The virtual screen identified CP2/LBP-1c/LSF as a factor that likely mediates enhanced transcription of GARS-AIRS-GART in DS-related AD.


Subject(s)
Alzheimer Disease/genetics , Carbon-Nitrogen Ligases/genetics , DNA-Binding Proteins/metabolism , Down Syndrome/genetics , Phosphoribosylglycinamide Formyltransferase/genetics , Transcription Factors/metabolism , Alzheimer Disease/etiology , Animals , Binding Sites , Carbon-Nitrogen Ligases/metabolism , Chromosome Mapping , Chromosomes, Human, Pair 21 , Computational Biology , DNA-Binding Proteins/genetics , DNA-Binding Proteins/physiology , Databases, Genetic , Down Syndrome/complications , Gene Expression Regulation , Genetic Linkage , Humans , Mice , Models, Biological , Phosphoribosylglycinamide Formyltransferase/metabolism , Protein Binding , Tissue Distribution , Transcription Factors/genetics , Transcription Factors/physiology , Transcription, Genetic
14.
Am J Med Genet B Neuropsychiatr Genet ; 141B(4): 361-6, 2006 Jun 05.
Article in English | MEDLINE | ID: mdl-16583436

ABSTRACT

Serotonin transporter (SLC6A4) polymorphisms are variously implicated in mediating susceptibility to attention-deficit-hyperactivity disorder (ADHD), a highly heritable and heterogeneous disorder with onset in childhood. Since there has been no survey in this regard from India, a sample of 56 ADHD cases and 174 healthy individuals from Kolkata were genotyped for the SLC6A4 promoter (5-HTTLPR) and intron-2 (STin2) polymorphisms. We report that the observed distribution of allele frequencies is consonant with that expected as per Hardy-Weinberg equilibrium proportions. Pair-wise combination of alleles comprising the 5-HTTLPR and STin2 polymorphic systems exhibit significant (chi(2) = 14.74, df = 1; P = 0.0001) linkage disequilibrium of low magnitude (D' = 0.269). The estimates of haplotype-based haplotype relative risk (HHRR) (chi(2) = 4.92, P = 0.027; RR = 1.47; 95% CI = 1.01-2.13) and transmission disequilibrium test (TDT) statistics (chi(2) = 7.00, P = 0.008; OR = 3.00; 95% CI = 1.53-5.90) using a family-based study design, indicate significant preferential transmission of the STin2.12 (A12) allele to ADHD cases. Maternal inheritance of the A12 allele is significant in terms of the HHRR (chi(2) = 6.53, P = 0.011; RR = 2.00; 95% CI = 1.08-3.72) and TDT (chi(2) = 8.07, P = 0.005; OR = 6.50; 95% CI = 1.76-23.98) suggesting a novel role for epigenetic mechanisms in the etiology of ADHD. Similar analyses yielded no evidence of association between the 5-HTTLPR polymorphism and ADHD. Studies including additional polymorphic markers, ADHD subjects and other ethnic groups are warranted to further substantiate the present findings.


Subject(s)
Attention Deficit Disorder with Hyperactivity/genetics , Introns/genetics , Polymorphism, Genetic , Serotonin Plasma Membrane Transport Proteins/genetics , Adult , Alleles , Child , Child, Preschool , Family Health , Female , Gene Frequency , Genotype , Humans , India , Linkage Disequilibrium , Male
15.
Indian Pediatr ; 42(4): 339-44, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15876595

ABSTRACT

Molecular aspects of Down syndrome (DS), a major genetic cause for mental retardation, commonly associated with trisomy 21 are discussed. Two different hypotheses have been speculated to better understand the disease. One believes that increased gene dosage contributes to the phenotypic abnormalities; the other correlates genetic imbalance with DS pathogenesis. To sustain these hypotheses, different murine models have been developed. Experimental models as well as sequencing of human chromosome 21 helped in speculating a few possible candidate genes for DS. However, the phenotypic changes involved with this neurological disorder vis-a-vis the enhanced number of genes, still remain unexplained. Improvement in screening pattern, model system, as well as better understanding of the disease etiology may help in developing efficacious therapeutic regimes for DS.


Subject(s)
Down Syndrome/genetics , Animals , Disease Models, Animal , Humans , Mice , Mice, Transgenic , Trisomy/genetics
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