Publications by authors named "Lili Senman"

9 Publications

  • Page 1 of 1

Whole genome sequencing resource identifies 18 new candidate genes for autism spectrum disorder.

Nat Neurosci 2017 Apr 6;20(4):602-611. Epub 2017 Mar 6.

The Centre for Applied Genomics, Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Canada.

We are performing whole-genome sequencing of families with autism spectrum disorder (ASD) to build a resource (MSSNG) for subcategorizing the phenotypes and underlying genetic factors involved. Here we report sequencing of 5,205 samples from families with ASD, accompanied by clinical information, creating a database accessible on a cloud platform and through a controlled-access internet portal. We found an average of 73.8 de novo single nucleotide variants and 12.6 de novo insertions and deletions or copy number variations per ASD subject. We identified 18 new candidate ASD-risk genes and found that participants bearing mutations in susceptibility genes had significantly lower adaptive ability (P = 6 × 10). In 294 of 2,620 (11.2%) of ASD cases, a molecular basis could be determined and 7.2% of these carried copy number variations and/or chromosomal abnormalities, emphasizing the importance of detecting all forms of genetic variation as diagnostic and therapeutic targets in ASD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nn.4524DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5501701PMC
April 2017

Rare deletions at the neurexin 3 locus in autism spectrum disorder.

Am J Hum Genet 2012 Jan 29;90(1):133-41. Epub 2011 Dec 29.

Program in Genetics and Genome Biology, The Centre for Applied Genomics, the Hospital for Sick Children, Toronto, Ontario, Canada.

The three members of the human neurexin gene family, neurexin 1 (NRXN1), neurexin 2 (NRXN2), and neurexin 3 (NRXN3), encode neuronal adhesion proteins that have important roles in synapse development and function. In autism spectrum disorder (ASD), as well as in other neurodevelopmental conditions, rare exonic copy-number variants and/or point mutations have been identified in the NRXN1 and NRXN2 loci. We present clinical characterization of four index cases who have been diagnosed with ASD and who possess rare inherited or de novo microdeletions at 14q24.3-31.1, a region that overlaps exons of the alpha and/or beta isoforms of NRXN3. NRXN3 deletions were found in one father with subclinical autism and in a carrier mother and father without formal ASD diagnoses, indicating issues of penetrance and expressivity at this locus. Notwithstanding these clinical complexities, this report on ASD-affected individuals who harbor NRXN3 exonic deletions advances the understanding of the genetic etiology of autism, further enabling molecular diagnoses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajhg.2011.11.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257896PMC
January 2012

Disruption at the PTCHD1 Locus on Xp22.11 in Autism spectrum disorder and intellectual disability.

Sci Transl Med 2010 Sep;2(49):49ra68

Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.

Autism is a common neurodevelopmental disorder with a complex mode of inheritance. It is one of the most highly heritable of the complex disorders, although the underlying genetic factors remain largely unknown. Here, we report mutations in the X-chromosome PTCHD1 (patched-related) gene in seven families with autism spectrum disorder (ASD) and in three families with intellectual disability. A 167-kilobase microdeletion spanning exon 1 was found in two brothers, one with ASD and the other with a learning disability and ASD features; a 90-kilobase microdeletion spanning the entire gene was found in three males with intellectual disability in a second family. In 900 probands with ASD and 208 male probands with intellectual disability, we identified seven different missense changes (in eight male probands) that were inherited from unaffected mothers and not found in controls. Two of the ASD individuals with missense changes also carried a de novo deletion at another ASD susceptibility locus (DPYD and DPP6), suggesting complex genetic contributions. In additional males with ASD, we identified deletions in the 5' flanking region of PTCHD1 that disrupted a complex noncoding RNA and potential regulatory elements; equivalent changes were not found in male control individuals. Thus, our systematic screen of PTCHD1 and its 5' flanking regions suggests that this locus is involved in ~1% of individuals with ASD and intellectual disability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/scitranslmed.3001267DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2987731PMC
September 2010

A genome-wide scan for common alleles affecting risk for autism.

Hum Mol Genet 2010 Oct 27;19(20):4072-82. Epub 2010 Jul 27.

Department of Psychiatry, School of Medicine, Trinity College, Dublin 8, Ireland.

Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 × 10(-8). When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner's curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 × 10(-8) threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/hmg/ddq307DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2947401PMC
October 2010

Functional impact of global rare copy number variation in autism spectrum disorders.

Nature 2010 Jul 9;466(7304):368-72. Epub 2010 Jun 9.

The Centre for Applied Genomics and Program in Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada.

The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviours. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability. Although ASDs are known to be highly heritable ( approximately 90%), the underlying genetic determinants are still largely unknown. Here we analysed the genome-wide characteristics of rare (<1% frequency) copy number variation in ASD using dense genotyping arrays. When comparing 996 ASD individuals of European ancestry to 1,287 matched controls, cases were found to carry a higher global burden of rare, genic copy number variants (CNVs) (1.19 fold, P = 0.012), especially so for loci previously implicated in either ASD and/or intellectual disability (1.69 fold, P = 3.4 x 10(-4)). Among the CNVs there were numerous de novo and inherited events, sometimes in combination in a given family, implicating many novel ASD genes such as SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53-PTCHD1 locus. We also discovered an enrichment of CNVs disrupting functional gene sets involved in cellular proliferation, projection and motility, and GTPase/Ras signalling. Our results reveal many new genetic and functional targets in ASD that may lead to final connected pathways.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature09146DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3021798PMC
July 2010

Mapping autism risk loci using genetic linkage and chromosomal rearrangements.

Nat Genet 2007 Mar 18;39(3):319-28. Epub 2007 Feb 18.

Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada.

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ng1985DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4867008PMC
March 2007

Absence of a paternally inherited FOXP2 gene in developmental verbal dyspraxia.

Am J Hum Genet 2006 Nov 27;79(5):965-72. Epub 2006 Sep 27.

The Centre for Applied Genomics and Program in Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Ontario, Canada.

Mutations in FOXP2 cause developmental verbal dyspraxia (DVD), but only a few cases have been described. We characterize 13 patients with DVD--5 with hemizygous paternal deletions spanning the FOXP2 gene, 1 with a translocation interrupting FOXP2, and the remaining 7 with maternal uniparental disomy of chromosome 7 (UPD7), who were also given a diagnosis of Silver-Russell Syndrome (SRS). Of these individuals with DVD, all 12 for whom parental DNA was available showed absence of a paternal copy of FOXP2. Five other individuals with deletions of paternally inherited FOXP2 but with incomplete clinical information or phenotypes too complex to properly assess are also described. Four of the patients with DVD also meet criteria for autism spectrum disorder. Individuals with paternal UPD7 or with partial maternal UPD7 or deletion starting downstream of FOXP2 do not have DVD. Using quantitative real-time polymerase chain reaction, we show the maternally inherited FOXP2 to be comparatively underexpressed. Our results indicate that absence of paternal FOXP2 is the cause of DVD in patients with SRS with maternal UPD7. The data also point to a role for differential parent-of-origin expression of FOXP2 in human speech development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1086/508902DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1698557PMC
November 2006

Speech and language impairment and oromotor dyspraxia due to deletion of 7q31 that involves FOXP2.

Am J Med Genet A 2006 Mar;140(5):509-14

Department of Pediatrics, McMaster University, Hamilton, Canada.

We report detailed clinical, cytogenetic, and molecular findings in a girl with a deletion of chromosome 7q31-q32. This child has a severe communication disorder with evidence of oromotor dyspraxia, dysmorphic features, and mild developmental delay. She is unable to cough, sneeze, or laugh spontaneously. Her deletion is on the paternally inherited chromosome and includes the FOXP2 gene, which has recently been associated with speech and language impairment and a similar form of oromotor dyspraxia in at least three other published cases. We hypothesize that our patient's communication disorder and oromotor deficiency are due to haploinsufficiency for FOXP2 and that her dysmorphism and developmental delay are a consequence of the absence of the other genes involved in the microdeletion. We propose that this patient, together with others reported in the literature, may define a new contiguous gene deletion syndrome encompassing the 7q31-FOXP2 region. Cytogenetic and molecular analysis of this region should be considered for other individuals displaying similar characteristics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajmg.a.31110DOI Listing
March 2006

Executive processes in appearance-reality tasks: the role of inhibition of attention and symbolic representation.

Child Dev 2004 Mar-Apr;75(2):562-79

Department of Psychology, York University, Toronto, Ontario, M3J 1P3, Canada.

Two studies addressed the role of representation ability and control of attention on solutions to an appearance-reality task based on two types of objects, real and representational. In Study 1, 67 preschool children (3-, 4-, and 5-year-olds) solved appearance-reality problems and executive processing tasks. There was an interaction between object type (real vs. representational) and question type (appearance vs. reality) on problem difficulty. In addition, representational ability predicted performance on appearance questions and inhibitory control predicted performance on reality questions. In Study 2, 95 children (4- and 5-year-olds) who were monolingual or bilingual solved similar problems. On appearance questions, groups performed equivalently but on reality questions, bilinguals performed better (once language proficiency had been controlled). The difference is attributed to the advanced inhibitory control that comes with bilingualism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1467-8624.2004.00693.xDOI Listing
July 2004
-->