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B. Lakshmi

Bio: B. Lakshmi is an academic researcher from Cold Spring Harbor Laboratory. The author has contributed to research in topics: Copy-number variation & Comparative genomic hybridization. The author has an hindex of 13, co-authored 18 publications receiving 9389 citations. Previous affiliations of B. Lakshmi include Ontario Institute for Cancer Research.

Papers
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Journal ArticleDOI
20 Apr 2007-Science
TL;DR: Findings establish de novo germline mutation as a more significant risk factor for ASD than previously recognized.
Abstract: We tested the hypothesis that de novo copy number variation (CNV) is associated with autism spectrum disorders (ASDs). We performed comparative genomic hybridization (CGH) on the genomic DNA of patients and unaffected subjects to detect copy number variants not present in their respective parents. Candidate genomic regions were validated by higher-resolution CGH, paternity testing, cytogenetics, fluorescence in situ hybridization, and microsatellite genotyping. Confirmed de novo CNVs were significantly associated with autism (P = 0.0005). Such CNVs were identified in 12 out of 118 (10%) of patients with sporadic autism, in 2 out of 77 (3%) of patients with an affected first-degree relative, and in 2 out of 196 (1%) of controls. Most de novo CNVs were smaller than microscopic resolution. Affected genomic regions were highly heterogeneous and included mutations of single genes. These findings establish de novo germline mutation as a more significant risk factor for ASD than previously recognized.

2,770 citations

Journal ArticleDOI
23 Jul 2004-Science
TL;DR: It is shown that large-scale copy number polymorphisms (CNPs) (about 100 kilobases and greater) contribute substantially to genomic variation between normal humans.
Abstract: The extent to which large duplications and deletions contribute to human genetic variation and diversity is unknown. Here, we show that large-scale copy number polymorphisms (CNPs) (about 100 kilobases and greater) contribute substantially to genomic variation between normal humans. Representational oligonucleotide microarray analysis of 20 individuals revealed a total of 221 copy number differences representing 76 unique CNPs. On average, individuals differed by 11 CNPs, and the average length of a CNP interval was 465 kilobases. We observed copy number variation of 70 different genes within CNP intervals, including genes involved in neurological function, regulation of cell growth, regulation of metabolism, and several genes known to be associated with disease.

2,572 citations

Journal ArticleDOI
25 Apr 2008-Science
TL;DR: The results suggest that multiple, individually rare mutations altering genes in neurodevelopmental pathways contribute to schizophrenia, and disrupted genes disproportionately from signaling networks controlling neurodevelopment, including neuregulin and glutamate pathways.
Abstract: Schizophrenia is a devastating neurodevelopmental disorder whose genetic influences remain elusive. We hypothesize that individually rare structural variants contribute to the illness. Microdeletions and microduplications >100 kilobases were identified by microarray comparative genomic hybridization of genomic DNA from 150 individuals with schizophrenia and 268 ancestry-matched controls. All variants were validated by high-resolution platforms. Novel deletions and duplications of genes were present in 5% of controls versus 15% of cases and 20% of young-onset cases, both highly significant differences. The association was independently replicated in patients with childhood-onset schizophrenia as compared with their parents. Mutations in cases disrupted genes disproportionately from signaling networks controlling neurodevelopment, including neuregulin and glutamate pathways. These results suggest that multiple, individually rare mutations altering genes in neurodevelopmental pathways contribute to schizophrenia.

1,762 citations

Journal ArticleDOI
TL;DR: A meta-analysis of datasets for multiple psychiatric disorders showed a significant association of the microduplication with schizophrenia, bipolar disorder, and autism, while the reciprocal microdeletion was associated only with autism and developmental disorders.
Abstract: Recurrent microdeletions and microduplications of a 600-kb genomic region of chromosome 16p11.2 have been implicated in childhood-onset developmental disorders1, 2, 3. We report the association of 16p11.2 microduplications with schizophrenia in two large cohorts. The microduplication was detected in 12/1,906 (0.63%) cases and 1/3,971 (0.03%) controls (P = 1.2 10-5, OR = 25.8) from the initial cohort, and in 9/2,645 (0.34%) cases and 1/2,420 (0.04%) controls (P = 0.022, OR = 8.3) of the replication cohort. The 16p11.2 microduplication was associated with a 14.5-fold increased risk of schizophrenia (95% CI (3.3, 62)) in the combined sample. A meta-analysis of datasets for multiple psychiatric disorders showed a significant association of the microduplication with schizophrenia (P = 4.8 10-7), bipolar disorder (P = 0.017) and autism (P = 1.9 10-7). In contrast, the reciprocal microdeletion was associated only with autism and developmental disorders (P = 2.3 10-13). Head circumference was larger in patients with the microdeletion than in patients with the microduplication (P = 0.0007).

689 citations

Journal ArticleDOI
09 Jun 2011-Neuron
TL;DR: The results show that, relative to males, females have greater resistance to autism from genetic causes, which raises the question of the fate of female carriers.

680 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
08 Oct 2009-Nature
TL;DR: This paper examined potential sources of missing heritability and proposed research strategies, including and extending beyond current genome-wide association approaches, to illuminate the genetics of complex diseases and enhance its potential to enable effective disease prevention or treatment.
Abstract: Genome-wide association studies have identified hundreds of genetic variants associated with complex human diseases and traits, and have provided valuable insights into their genetic architecture. Most variants identified so far confer relatively small increments in risk, and explain only a small proportion of familial clustering, leading many to question how the remaining, 'missing' heritability can be explained. Here we examine potential sources of missing heritability and propose research strategies, including and extending beyond current genome-wide association approaches, to illuminate the genetics of complex diseases and enhance its potential to enable effective disease prevention or treatment.

7,797 citations

Journal ArticleDOI
TL;DR: A technical review of template preparation, sequencing and imaging, genome alignment and assembly approaches, and recent advances in current and near-term commercially available NGS instruments is presented.
Abstract: Demand has never been greater for revolutionary technologies that deliver fast, inexpensive and accurate genome information. This challenge has catalysed the development of next-generation sequencing (NGS) technologies. The inexpensive production of large volumes of sequence data is the primary advantage over conventional methods. Here, I present a technical review of template preparation, sequencing and imaging, genome alignment and assembly approaches, and recent advances in current and near-term commercially available NGS instruments. I also outline the broad range of applications for NGS technologies, in addition to providing guidelines for platform selection to address biological questions of interest.

7,023 citations

Journal ArticleDOI
John W. Belmont1, Andrew Boudreau, Suzanne M. Leal1, Paul Hardenbol  +229 moreInstitutions (40)
27 Oct 2005
TL;DR: A public database of common variation in the human genome: more than one million single nucleotide polymorphisms for which accurate and complete genotypes have been obtained in 269 DNA samples from four populations, including ten 500-kilobase regions in which essentially all information about common DNA variation has been extracted.
Abstract: Inherited genetic variation has a critical but as yet largely uncharacterized role in human disease. Here we report a public database of common variation in the human genome: more than one million single nucleotide polymorphisms (SNPs) for which accurate and complete genotypes have been obtained in 269 DNA samples from four populations, including ten 500-kilobase regions in which essentially all information about common DNA variation has been extracted. These data document the generality of recombination hotspots, a block-like structure of linkage disequilibrium and low haplotype diversity, leading to substantial correlations of SNPs with many of their neighbours. We show how the HapMap resource can guide the design and analysis of genetic association studies, shed light on structural variation and recombination, and identify loci that may have been subject to natural selection during human evolution.

5,479 citations

Journal ArticleDOI
Shaun Purcell1, Shaun Purcell2, Naomi R. Wray3, Jennifer Stone2, Jennifer Stone1, Peter M. Visscher, Michael Conlon O'Donovan4, Patrick F. Sullivan5, Pamela Sklar1, Pamela Sklar2, Douglas M. Ruderfer, Andrew McQuillin, Derek W. Morris6, Colm O'Dushlaine6, Aiden Corvin6, Peter Holmans4, Stuart MacGregor3, Hugh Gurling, Douglas Blackwood7, Nicholas John Craddock5, Michael Gill6, Christina M. Hultman8, Christina M. Hultman9, George Kirov4, Paul Lichtenstein9, Walter J. Muir7, Michael John Owen4, Carlos N. Pato10, Edward M. Scolnick2, Edward M. Scolnick1, David St Clair, Nigel Williams4, Lyudmila Georgieva4, Ivan Nikolov4, Nadine Norton4, Hywel Williams4, Draga Toncheva, Vihra Milanova, Emma Flordal Thelander9, Patrick Sullivan11, Elaine Kenny6, Emma M. Quinn6, Khalid Choudhury12, Susmita Datta12, Jonathan Pimm12, Srinivasa Thirumalai13, Vinay Puri12, Robert Krasucki12, Jacob Lawrence12, Digby Quested14, Nicholas Bass12, Caroline Crombie15, Gillian Fraser15, Soh Leh Kuan, Nicholas Walker, Kevin A. McGhee7, Ben S. Pickard16, P. Malloy7, Alan W Maclean7, Margaret Van Beck7, Michele T. Pato10, Helena Medeiros10, Frank A. Middleton17, Célia Barreto Carvalho10, Christopher P. Morley17, Ayman H. Fanous, David V. Conti10, James A. Knowles10, Carlos Ferreira, António Macedo18, M. Helena Azevedo18, Andrew Kirby1, Andrew Kirby2, Manuel A. R. Ferreira1, Manuel A. R. Ferreira2, Mark J. Daly2, Mark J. Daly1, Kimberly Chambert2, Finny G Kuruvilla2, Stacey Gabriel2, Kristin G. Ardlie2, Jennifer L. Moran2 
06 Aug 2009-Nature
TL;DR: The extent to which common genetic variation underlies the risk of schizophrenia is shown, using two analytic approaches, and the major histocompatibility complex is implicate, which is shown to involve thousands of common alleles of very small effect.
Abstract: Schizophrenia is a severe mental disorder with a lifetime risk of about 1%, characterized by hallucinations, delusions and cognitive deficits, with heritability estimated at up to 80%(1,2). We performed a genome-wide association study of 3,322 European individuals with schizophrenia and 3,587 controls. Here we show, using two analytic approaches, the extent to which common genetic variation underlies the risk of schizophrenia. First, we implicate the major histocompatibility complex. Second, we provide molecular genetic evidence for a substantial polygenic component to the risk of schizophrenia involving thousands of common alleles of very small effect. We show that this component also contributes to the risk of bipolar disorder, but not to several non-psychiatric diseases.

4,573 citations