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Author

María Dolores Moltó

Other affiliations: Baylor College of Medicine
Bio: María Dolores Moltó is an academic researcher from University of Valencia. The author has contributed to research in topics: Frataxin & Ataxia. The author has an hindex of 25, co-authored 59 publications receiving 3925 citations. Previous affiliations of María Dolores Moltó include Baylor College of Medicine.
Topics: Frataxin, Ataxia, Haplotype, Prefrontal cortex, Gene


Papers
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Journal ArticleDOI
08 Mar 1996-Science
TL;DR: A few FRDA patients were found to have point mutations in X25, but the majority were homozygous for an unstable GAA trinucleotide expansion in the first X25 intron.
Abstract: Friedreich's ataxia (FRDA) is an autosomal recessive, degenerative disease that involves the central and peripheral nervous systems and the heart. A gene, X25, was identified in the critical region for the FRDA locus on chromosome 9q13. This gene encodes a 210-amino acid protein, frataxin, that has homologs in distant species such as Caenorhabditis elegans and yeast. A few FRDA patients were found to have point mutations in X25, but the majority were homozygous for an unstable GAA trinucleotide expansion in the first X25 intron.

2,552 citations

Journal ArticleDOI
TL;DR: In this article , a two-stage genome-wide association study of up to 76,755 individuals with schizophrenia and 243,649 control individuals was conducted, and the authors reported common variant associations at 287 distinct genomic loci.
Abstract: Schizophrenia has a heritability of 60–80%1, much of which is attributable to common risk alleles. Here, in a two-stage genome-wide association study of up to 76,755 individuals with schizophrenia and 243,649 control individuals, we report common variant associations at 287 distinct genomic loci. Associations were concentrated in genes that are expressed in excitatory and inhibitory neurons of the central nervous system, but not in other tissues or cell types. Using fine-mapping and functional genomic data, we identify 120 genes (106 protein-coding) that are likely to underpin associations at some of these loci, including 16 genes with credible causal non-synonymous or untranslated region variation. We also implicate fundamental processes related to neuronal function, including synaptic organization, differentiation and transmission. Fine-mapped candidates were enriched for genes associated with rare disruptive coding variants in people with schizophrenia, including the glutamate receptor subunit GRIN2A and transcription factor SP4, and were also enriched for genes implicated by such variants in neurodevelopmental disorders. We identify biological processes relevant to schizophrenia pathophysiology; show convergence of common and rare variant associations in schizophrenia and neurodevelopmental disorders; and provide a resource of prioritized genes and variants to advance mechanistic studies. A genome-wide association study including over 76,000 individuals with schizophrenia and over 243,000 control individuals identifies common variant associations at 287 genomic loci, and further fine-mapping analyses highlight the importance of genes involved in synaptic processes.

558 citations

Journal ArticleDOI
TL;DR: It is proposed that in FA, the oxidative mediated inactivation of aconitase, which occurs normally during the aging process, is enhanced due to the lack of frataxin, and an important role of oxidative stress in the progression of FA is supported.
Abstract: Friedreich ataxia (FA), the most common form of hereditary ataxia, is caused by a deficit in the mitochondrial protein frataxin. While several hypotheses have been suggested, frataxin function is not well understood. Oxidative stress has been suggested to play a role in the pathophysiology of FA, but this view has been recently questioned, and its link to frataxin is unclear. Here, we report the use of RNA interference (RNAi) to suppress the Drosophila frataxin gene (fh) expression. This model system parallels the situation in FA patients, namely a moderate systemic reduction of frataxin levels compatible with normal embryonic development. Under these conditions, fh-RNAi flies showed a shortened life span, reduced climbing abilities, and enhanced sensitivity to oxidative stress. Under hyperoxia, fh-RNAi flies also showed a dramatic reduction of aconitase activity that seriously impairs the mitochondrial respiration while the activities of succinate dehydrogenase, respiratory complex I and II, and indirect...

122 citations

Journal ArticleDOI
TL;DR: The results show that mPFC inhibitory networks are affected by chronic stress and suggest that structural plasticity may be an important feature of stress-related psychiatric disorders where this cortical region, specially their GABAergic system, is altered.
Abstract: Chronic stress in experimental animals induces dendritic atrophy and decreases spine density in principal neurons of the medial prefrontal cortex (mPFC) This structural plasticity may play a neuroprotective role and underlie stress-induced behavioral changes Different evidences indicate that the prefrontocortical GABA system is also altered by stress and in major depression patients In the amygdala, chronic stress induces dendritic remodeling both in principal neurons and in interneurons However, it is not known whether similar structural changes occur in mPFC interneurons The polysialylated form of the neural cell adhesion molecule (PSA-NCAM) may mediate these changes, because it is known to influence the dendritic organization of adult cortical interneurons We have analyzed the dendritic arborization and spine density of mPFC interneurons in adult mice after 21 days of restraint stress and have found dendritic hypertrophy in a subpopulation of interneurons identified mainly as Martinotti cells This aversive experience also decreases the number of glutamate decarboxylase enzyme, 67 kDa isoform (GAD67) expressing somata, without affecting different parameters related to apoptosis, but does not alter the number of interneurons expressing PSA-NCAM Quantitative retrotranscription-polymerase chain reaction (qRT-PCR) analysis of genes related to general and inhibitory neurotransmission and of PSA synthesizing enzymes reveals increases in the expression of NCAM, synaptophysin and GABA(A)α1 Together these results show that mPFC inhibitory networks are affected by chronic stress and suggest that structural plasticity may be an important feature of stress-related psychiatric disorders where this cortical region, specially their GABAergic system, is altered

112 citations

Journal ArticleDOI
TL;DR: FOXP2 might be involved in the language disorder in patients with schizophrenia, and Epigenetic factors might be also implicated in the developing of this disorder.
Abstract: Schizophrenia is considered a language related human specific disease. Previous studies have reported evidence of positive selection for schizophrenia-associated genes specific to the human lineage. FOXP2 shows two important features as a convincing candidate gene for schizophrenia vulnerability: FOXP2 is the first gene related to a language disorder, and it has been subject to positive selection in the human lineage. Twenty-seven SNPs of FOXP2 were genotyped in a cohort of 293 patients with schizophrenia and 340 controls. We analyzed in particular the association with the poverty of speech and the intensity of auditory hallucinations. Potential expansion of three trinucleotide repeats of FOXP2 was also screened in a subsample. Methylation analysis of a CpG island, located in the first exon of the gene, was performed in post-mortem brain samples, as well as qRT-PCR analysis. A significant association was found between the SNP rs2253478 and the item Poverty of speech of the Manchester scale (p = 0.038 after Bonferroni correction). In patients, we detected higher degree of methylation in the left parahippocampus gyrus than in the right one. FOXP2 might be involved in the language disorder in patients with schizophrenia. Epigenetic factors might be also implicated in the developing of this disorder.

105 citations


Cited by
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Journal ArticleDOI
TL;DR: A new algorithm for finding tandem repeats which works without the need to specify either the pattern or pattern size is presented and its ability to detect tandem repeats that have undergone extensive mutational change is demonstrated.
Abstract: A tandem repeat in DNA is two or more contiguous, approximate copies of a pattern of nucleotides. Tandem repeats have been shown to cause human disease, may play a variety of regulatory and evolutionary roles and are important laboratory and analytic tools. Extensive knowledge about pattern size, copy number, mutational history, etc. for tandem repeats has been limited by the inability to easily detect them in genomic sequence data. In this paper, we present a new algorithm for finding tandem repeats which works without the need to specify either the pattern or pattern size. We model tandem repeats by percent identity and frequency of indels between adjacent pattern copies and use statistically based recognition criteria. We demonstrate the algorithm’s speed and its ability to detect tandem repeats that have undergone extensive mutational change by analyzing four sequences: the human frataxin gene, the human β T cell receptor locus sequence and two yeast chromosomes. These sequences range in size from 3 kb up to 700 kb. A World Wide Web server interface at c3.biomath.mssm.edu/trf.html has been established for automated use of the program.

6,577 citations

Journal ArticleDOI
TL;DR: Oxidative stress has been implicated in the progression of Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis and different strategies, including novel metal–protein attenuating compounds aimed at a variety of targets have shown promise in clinical studies.
Abstract: Oxidative stress has been implicated in the progression of Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Oxygen is vital for life but is also potentially dangerous, and a complex system of checks and balances exists for utilizing this essential element. Oxidative stress is the result of an imbalance in pro-oxidant/antioxidant homeostasis that leads to the generation of toxic reactive oxygen species. The systems in place to cope with the biochemistry of oxygen are complex, and many questions about the mechanisms of oxygen regulation remain unanswered. However, this same complexity provides a number of therapeutic targets, and different strategies, including novel metal-protein attenuating compounds, aimed at a variety of targets have shown promise in clinical studies.

3,376 citations

Journal ArticleDOI
TL;DR: It is concluded that a small polyglutamine expansion in the human α1A calcium channel is most likely the cause of a newly classified autosomal dominant spinocerebellar ataxia, SCA6.
Abstract: A polymorphic CAG repeat was identified in the human α1A voltage-dependent calcium channel subunit. To test the hypothesis that expansion of this CAG repeat could be the cause of an inherited progressive ataxia, we genotyped a large number of unrelated controls and ataxia patients. Eight unrelated patients with late onset ataxia had alleles with larger repeat numbers (21‐27) compared to the number of repeats (4‐16) in 475 non‐ataxia individuals. Analysis of the repeat length in families of the affected individuals revealed that the expansion segregated with the phenotype in every patient. We identified six isoforms of the human α1A calcium channel subunit. The CAG repeat is within the open reading frame and is predicted to encode glutamine in three of the isoforms. We conclude that a small polyglutamine expansion in the human α1A calcium channel is most likely the cause of a newly classified autosomal dominant spinocerebellar ataxia, SCA6.

1,558 citations

Journal ArticleDOI
TL;DR: During the past 65 million years, Alu elements have propagated to more than one million copies in primate genomes, which has resulted in the generation of a series of Alu subfamilies of different ages.
Abstract: During the past 65 million years, Alu elements have propagated to more than one million copies in primate genomes, which has resulted in the generation of a series of Alu subfamilies of different ages. Alu elements affect the genome in several ways, causing insertion mutations, recombination between elements, gene conversion and alterations in gene expression. Alu-insertion polymorphisms are a boon for the study of human population genetics and primate comparative genomics because they are neutral genetic markers of identical descent with known ancestral states.

1,415 citations

Journal ArticleDOI
TL;DR: It is exciting that within a span of 15 years, pathogenesis studies of this class of disorders are beginning to reveal pathways that are potential therapeutic targets.
Abstract: The discovery that expansion of unstable repeats can cause a variety of neurological disorders has changed the landscape of disease-oriented research for several forms of mental retardation, Huntington disease, inherited ataxias, and muscular dystrophy. The dynamic nature of these mutations provided an explanation for the variable phenotype expressivity within a family. Beyond diagnosis and genetic counseling, the benefits from studying these disorders have been noted in both neurobiology and cell biology. Examples include insight about the role of translational control in synaptic plasticity, the role of RNA processing in the integrity of muscle and neuronal function, the importance of Fe-S-containing enzymes for cellular energy, and the dramatic effects of altering protein conformations on neuronal function and survival. It is exciting that within a span of 15 years, pathogenesis studies of this class of disorders are beginning to reveal pathways that are potential therapeutic targets.

1,341 citations