Characterization of the functional impact of <i>SHANK2</i> mutations in cultured neuronal cells.

<p>A. The colocalization of <i>ProSAP1A/SHANK2</i>-EGFP (postsynaptic marker) and Bassoon (presynaptic marker) indicated that the mutations did not disturb the formation of SHANK2 clusters at excitatory synapses along the dendrites. B. The quantification of synapse density was performed on 20 transfected hippocampal neurons per construct from at least three independent experiments. The majority of the <i>ProSAP1A</i> variants affecting a conserved amino acid among SHANK proteins reduced significantly the synaptic density compared with the variants that affect amino acid non conserved among SHANK proteins (Mann-Whitney U-test: n_WT = 20, n_mut = 20; U_S557N = 82.5, p_S557N = 0.001; U_R569H = 124, p_R569H = 0.04; U_L629P = 149, p_L629P = 0.17; U_V717F = 114, p_V717F = 0.02; U_A729T = 73, p_A729T = 0.000; U_K780Q = 154, p_K780Q = 0.221; U_R818H = 108, p_R818H = 0.012; U_A822T = 154.5, p_A822T = 0.224; U_V823M = 129, p_V823M = 0.056; U_Y967C = 134, p_Y967C = 0.076; U_G1170R = 78, p_G1170R = 0.001; U_R1290W = 142, p_R1290W = 0.121; U_Q1308R = 162, p_Q1308R = 0.314; U_D1535N = 97, p_D1535N = 0.005; U_P1586L = 137, p_P1586L = 0.910; U_L1722P = 79, p_L1722P = 0.001, *p<0.05, **p<0.01, ***p<0.001). <b>C.</b> Effect of the variants on synaptic density. The y-axis represents −log P compared to WT (P obtained with Mann-Whitney test). After Bonferroni correction for 16 tests, only P values<0.003 were considered as significant. Variants represented in red were specific to ASD, in orange were shared by ASD and controls, and in green were specific to the controls. Open circles and filled circles represent non conserved and conserved amino acids, respectively. Prim, primary; second, secondary.</p

Scatter plots of the intellectual quotient and the Autism Diagnostic Interview-Revised (ADI-R) scores of the patients with ASD screened for <i>SHANK1-3</i> mutations.

<p>Mutations in <i>SHANK1-3</i> are associated with a gradient of severity in cognitive impairment. <i>SHANK1</i> mutations were reported in patients without ID (green dots). <i>SHANK2</i> mutations were reported in patients with mild ID (orange dots). <i>SHANK3</i> mutations were found in patients with moderate to severe deficit (red dots). Black dots correspond to the patients enrolled in the PARIS cohort screened for deleterious <i>SHANK1-3</i> mutations (n = 498). In addition to the PARIS cohort <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Durand1" target="_blank">[6]</a>, <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Pinto1" target="_blank">[8]</a>, <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Leblond1" target="_blank">[18]</a>, three patients with a <i>SHANK1</i> deletion <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Sato1" target="_blank">[19]</a> and two patients with a <i>SHANK2</i> deletion <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Berkel1" target="_blank">[14]</a> were included in the scatter plot. A high score of the ADI-R is associated with a more severe profile. The threshold of the “Social”, “Verbal”, “Non-Verbal” and “Repetitive Behavior” Scores are 10, 8, 7 and 3, respectively.</p

Genetic alterations identified in the control subject SWE_Q56_508.

<p>A. <i>SHANK2</i> splice mutation (IVS22+1G>T) detected in a Swedish female control, SWE_Q56_508. The mutation altered the donor splicing site of exon 22 and led to a premature stop in all <i>SHANK2</i> isoforms except for the <i>AF1411901</i> isoform, where it altered the protein sequence (G263V). B. CNVs in the same individual altering <i>LOC339822</i>, <i>SNTG2</i>, <i>PXDN</i> and <i>MYT1L</i>. The two close duplications span 264 kb and 245 kb on chromosome 2 and altered <i>LOC339822</i> and <i>SNTG2</i>, and <i>PXDN</i> and <i>MYT1L</i>, respectively. Dots show the B allele frequency (BAF; in green), Log R ratio (LRR; in red), and QuantiSNP score (in blue). Lower panel: all CNVs listed in the Database of Genomic Variants (DGV) are represented: loss (in red), gain (in blue), gain or loss (in brown). H, homer binding site; D, dynamin binding site; C, cortactin binding site.</p

Prevalence and meta-analysis of coding-sequence variant studies in ASD.

<p>A. The prevalence and the confidence interval from a set of single coding-sequence variant studies, and the pooled prevalence and the confidence interval of the meta-analysis. The prevalence is indicated by circles in red, pink, purple and black for “ASD all” (all ASD patients), “ASD IQ<70” (patients with ID; IQ<70), “ASD IQ>70” (patients with normal IQ), and “CTRL” (controls), respectively. Three categories are used to study the prevalence of coding-sequence variants in ASD and controls: all or “A” (all mutation), Damaging or “D” (damaging missense mutation; score obtained from polyphen-2), and Truncating or “T” (mutation altering SHANK protein). The plotted circles are proportional to the corresponding sample size. B. Meta-analysis of coding-sequence variant studies altering <i>SHANK</i> genes. For each study, the Odds ratio and confidence interval is given. Each meta-analysis is calculated using inverse variance method for fixed (IV-FEM) and random effects (IV-REM). The statistics measuring heterogeneity (Q, I² and Tau²) are indicated. The number under the scatter plot correspond to independent studies: 1 = “This study”, 2 = “ Sato et al. (2012) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Sato1" target="_blank">[19]</a>”, 3 = “Berkel et al. (2010) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Berkel1" target="_blank">[14]</a>”, 4 = “Leblond et al. (2012) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Leblond1" target="_blank">[18]</a>”, 5 = “Boccuto et al. (2012) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Boccuto1" target="_blank">[17]</a>”, and 6 = “[This Study and Durand et al. 2007 <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Durand1" target="_blank">[6]</a>]”, 7 = “[Gauthier et al. (2009–2010) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Gauthier1" target="_blank">[16]</a>, <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Gauthier2" target="_blank">[47]</a>]”, 8 = “Moessner et al. (2007) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Moessner1" target="_blank">[13]</a>”, 9 = “Schaff et al. (2011) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Schaaf1" target="_blank">[35]</a>”. IV, Inverse Variance; FEM, Fixed Effect Method; REM, Random Effect Method; OR, Odds Ratio; CI, Confidence Interval; IQ, Intellectual Quotient; CNV, Copy Number Variant.</p

<i>SHANK2</i> mutations in patients with ASD.

<p>A. A heterozygous deletion of <i>SHANK2</i> was identified with the Illumina Human 1M-Duo SNP array in a patient with autism (AU038_3). The deletion spans 421 kb on chromosome 11q13.3, covers twelve exons of the human <i>SHANK2</i> and is not present in the parents. Each dot shows Log R Ratio (LRR; in red) and B allele frequency (BAF; in green). QuantiSNP score is represented with a blue line and indicates the deletion size. B. Location of the CNV and sequence variants (from this study and Berkel <i>et al.</i> 2010) along the SHANK2 protein: in red the variations specific to ASD, in orange the variations shared by ASD and controls and in green the variations specific to controls <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002521#pgen.1002521-Berkel1" target="_blank">[26]</a>. The breakpoints of the <i>SHANK2</i> deletion in AU038_3 are represented with a dotted line on the protein. Stars indicate the variants affecting conserved amino acids. C. A total of 40 variants were identified and variants affecting conserved amino acids in other SHANK proteins are enriched in patients with ASD (n_conserved = 12 and n_{non-conserved} = 3) compared with controls (n_conserved = 6 and n_{non-conserved} = 11) (Fisher's exact test 1-sided, P = 0.013, OR = 6.83, 95% IC = 1.19–53.40). D. The percentage of carriers of <i>SHANK2</i> variants in patients with ASD and Controls. Variants affecting a conserved amino acid among the SHANK proteins are enriched in patients with ASD (n_conserved = 29 and n_{non-conserved} = 822) compared with controls (n_conserved = 16 and n_{non-conserved} = 1074) (Fisher's exact test 1-sided, P = 0.004, OR = 2.37, 95% CI = 1.23–4.70). Open squares and filled squares represent the non-conserved and conserved amino acids, respectively. ANK, Ankyrin repeat domain; SH3, Src homology 3 domain; PDZ, postsynaptic density 95/Discs large/zona occludens-1 homology domain; SAM, sterile alpha motif domain; BSR, brain specific region; H, homer binding site; D, dynamin binding site; C, cortactin binding site. The proline-rich region is represented as a horizontal gray line.</p

<i>SHANK</i> variants in patients with ASD and controls.

<p>Coding-sequence variants identified only in patients with ASD (upper panel), shared by patients and controls (lower panel and underlined), and present only in controls (lower panel). Truncating variants are indicated in red. The variants predicted as deleterious or benign are indicated in orange and green, respectively. Coding-sequence variants with a proven <i>in vitro</i> functional impact are indicated with black stars. Conserved domains are represented in color: SPN (yellow), Ankyrin (red), SH3 (orange), PDZ (blue) and SAM (green).</p

Characterization of CNVs in three patients carrying a <i>de novo</i> deletion of <i>SHANK2</i>.

<p>Paternally or maternally inherited CNVs are indicated by squares and circles, respectively. <i>De novo</i> CNVs are indicated by stars. Deletions and duplications are indicated in red and blue, respectively. CNVs hitting exons or only introns are filled with grey and white, respectively. Squares and circles within star represent <i>de novo</i> CNV of paternal or maternal origin; circles within squares represent CNV inherited by father or mother. ABCC6, ATP-binding cassette, sub-family C, member 6 pseudogene 2; ADAM, ADAM metallopeptidase; AMY1, amylase (salivary); AMY2A, amylase (pancreatic); ARHGAP11B, Rho GTPase activating protein 11B; CAMSAP1L1, calmodulin regulated spectrin-associated protein 1-like 1; CHRNA7, cholinergic receptor, nicotinic, alpha 7; CNTN4, contactin 4; CTNNA3, catenin (cadherin-associated protein), alpha 3; CYFIP1, cytoplasmic FMR1 interacting protein 1; DUSP22, dual specificity phosphatase 22; GALM, galactose mutarotase; GCNT2, glucosaminyl (N-acetyl) transferase 2; GOLGA, golgi autoantigen, golgin subfamily a; GSTT1, glutathione S-transferase theta 1; HLA-DRB, major histocompatibility complex, class II, DR beta; LAMA4, laminin, alpha 4; NIPA, non imprinted in Prader-Willi/Angelman syndrome; NLGN1, neuroligin 1; NME7, non-metastatic cells 7; OR, olfactory receptor; PCDHA, protocadherin alpha; RFPL4B, ret finger protein-like 4B; RHD, Rh blood group, D antigen; SFMBT1, Scm-like with four mbt domains 1; SHANK2, SH3 and multiple ankyrin repeat domains 2; SMC2, structural maintenance of chromosomes 2; TNS3, tensin 3; TUBGCP5, tubulin, gamma complex associated protein 5; UGT2B17, UDP glucuronosyltransferase 2 family, polypeptide B17.</p

Genomic structure, isoforms, and expression of human <i>SHANK2</i>.

<p>A. Genomic structure of the human <i>SHANK2</i> gene. Transcription of <i>SHANK2</i> produces four main mRNA from three distinct promoters: <i>SHANK2E</i> (<i>AB208025</i>), <i>ProSAP1A</i> (<i>AB208026</i>), <i>ProSAP1</i> (<i>AB208027</i>) and <i>AF141901</i>. There are three translation starts: in exon 2 for <i>SHANK2E</i>, in exon1b for <i>ProSAP1A</i>, and in exon1c for <i>ProSAP1</i> and <i>AF141901</i>; and two independent stop codons: in exon 22b for <i>AF141901</i> and in exon 25 for <i>SHANK2E</i>, <i>ProSAP1A</i> and <i>ProSAP1</i>. Conserved domains of protein interaction or protein binding site are represented in color: ANK (red), SH3 (orange), PDZ (blue) and SAM (green), H (pink), D, (dark blue) and C (purple). Black stars identify the alternative spliced exons (‘brain-specific exons’ in turquoise: 19, 20 and 23). B. RT-PCRs of <i>SHANK2</i> isoforms on RNA from different human control tissues (Clontech), and different brain regions of four controls (2 males and 2 females). The amplified regions specific to each isoform of <i>SHANK2</i> are indicated by gray boxes. C. Alternative splicing of human <i>SHANK2</i>; exons 19, 20 and 23 are specific to the brain. ANK, ankyrin; SH3, Src homology 3; PDZ, PSD95/DLG/ZO1; SAM, sterile alpha motif; He, heart; Li, liver; B, brain; SM, skeletal muscle; Pl, placenta; K, kidney; Lu, lung; Pa, pancreas; FC, frontal cortex; Hi, hippocampus; TC, temporal cortex; T, thalamus; OC, occipital cortex; Ce, cerebellum; Cx, whole cortex; BLCL, B lymphoblastoid cell lines; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; BSR, brain specific region; H, homer binding site; D, dynamin binding site; C, cortactin binding site. The ages of the two males and the two females studied were 74, 42, 55, and 36 years with a post-mortem interval of 10, 21, 24, and 2 h, respectively.</p

Summary of the SHANK protein functions and of the main findings obtained for patients with ASD.

<p>The frequency of mutation in patients and control individuals was calculated from the total cohort (<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen-1004580-t001" target="_blank">Table 1</a>). The frequency of mutation in patients with normal IQ (IQ>70) and low IQ (IQ<70) were calculated for the patients with available IQ scores (copy-number variants for all SHANK: nASD with IQ>70 = 1 638 & nASD with IQ<70 = 917; SHANK1 coding-sequence variants: nASD with IQ>70 = 354 and nASD with IQ<70 = 278; SHANK2 coding-sequence variants: nASD with IQ>70 = 335 & nASD with IQ<70 = 344; SHANK3 coding-sequence variants: nASD with IQ>70 = 667 & nASD with IQ<70 = 611). The mean IQ and standard deviation was given only for patients carrying truncating or <i>de novo</i> mutations. The black star indicates that Schmeisser et al. (2012) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Bonaglia1" target="_blank">[21]</a> found an increase in NMDA currents, while Won et al. (2012) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Betancur2" target="_blank">[22]</a> found a decrease in NMDA currents in two independent SHANK2 knock-out mice.</p><p>Summary of the SHANK protein functions and of the main findings obtained for patients with ASD.</p

Inherited 15q11–q13 CNVs identified in three ASD patients carrier of a <i>de novo</i> SHANK2 deletion.

<p>Deletions (del) and duplications (dup) are indicated in red and blue, respectively. Paternally and maternally imprinted genes are indicated in yellow and pink, respectively. Genes altered by the CNVs are indicated in blue or red. The bottom part of the figure indicates the location of the deletions/duplications previously associated with neuropsychiatric disorders <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002521#pgen.1002521-Miller1" target="_blank">[43]</a>–<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002521#pgen.1002521-deKovel1" target="_blank">[61]</a>. BP, breakpoint; Inh_M, inherited by mother; Inh_F, inherited by father; AS, Angelman syndrome; ASD, Autism spectrum disorders; ADHD, attention deficit-hyperactivity disorder; BP, bipolar disorder; DD: developmental delay; DBD, disruptive behavior disorder; EPI, epilepsy; GAD, generalized anxiety disorder; OCD, obsessive-compulsive disorder; ID, intellectual disability; PWS, Prader-Willi syndrome; SCZ, schizophrenia.</p