Meta-analysis of SHANK Mutations in Autism Spectrum Disorders: A Gradient of Severity in Cognitive Impairments.

International audienceSHANK genes code for scaffold proteins located at the post-synaptic density of glutamatergic synapses. In neurons, SHANK2 and SHANK3 have a positive effect on the induction and maturation of dendritic spines, whereas SHANK1 induces the enlargement of spine heads. Mutations in SHANK genes have been associated with autism spectrum disorders (ASD), but their prevalence and clinical relevance remain to be determined. Here, we performed a new screen and a meta-analysis of SHANK copy-number and coding-sequence variants in ASD. Copy-number variants were analyzed in 5,657 patients and 19,163 controls, coding-sequence variants were ascertained in 760 to 2,147 patients and 492 to 1,090 controls (depending on the gene), and, individuals carrying de novo or truncating SHANK mutations underwent an extensive clinical investigation. Copy-number variants and truncating mutations in SHANK genes were present in ∼1% of patients with ASD: mutations in SHANK1 were rare (0.04%) and present in males with normal IQ and autism; mutations in SHANK2 were present in 0.17% of patients with ASD and mild intellectual disability; mutations in SHANK3 were present in 0.69% of patients with ASD and up to 2.12% of the cases with moderate to profound intellectual disability. In summary, mutations of the SHANK genes were detected in the whole spectrum of autism with a gradient of severity in cognitive impairment. Given the rare frequency of SHANK1 and SHANK2 deleterious mutations, the clinical relevance of these genes remains to be ascertained. In contrast, the frequency and the penetrance of SHANK3 mutations in individuals with ASD and intellectual disability-more than 1 in 50-warrant its consideration for mutation screening in clinical practice

<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

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

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

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

Prevalence of <i>SHANK</i> rare coding-sequence and copy-number variants in patients with ASD and controls.

a<p>All truncating <i>SHANK</i> variants were <i>de novo</i> (for three, the DNA of one parent was not available). In the damaging missense category, two <i>SHANK3</i> (P141A & Q321R) were <i>de novo</i>.</p>b<p>For <i>SHANK1</i>, there are two studies (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> and this study), but 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> did not screen for all <i>SHANK1</i> exons in the controls. Therefore these controls were not included here.</p>c<p>The two <i>SHANK3</i> deletions reported by Glessner et al. (2009) <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004580#pgen.1004580-Glessner1" target="_blank">[34]</a> in control subjects have not been validated and should be interpreted with caution. The frequencies of <i>SHANK</i> mutations have been calculated including only unrelated cases and controls. FEM, Fixed Effects Model; REM, Random Effects Model. After Bonferroni correction for 12 tests (significant threshold corrected α-value = 0.0042), only the <i>SHANK3</i> copy-number variant association remains significant. The power achieved to observe the statistical difference between patients and controls for <i>SHANK1</i> and <i>SHANK2</i> damaging missense variants was 69% and 59%.</p><p>Prevalence of <i>SHANK</i> rare coding-sequence and copy-number variants in patients with ASD and controls.</p

Analysis of Outcomes in Ischemic vs Nonischemic Cardiomyopathy in Patients With Atrial Fibrillation A Report From the GARFIELD-AF Registry

IMPORTANCE Congestive heart failure (CHF) is commonly associated with nonvalvular atrial fibrillation (AF), and their combination may affect treatment strategies and outcomes