Segregation of Kallmann Syndrome and the <i>PROKR2</i> or <i>PROK2</i> Mutations in Affected Families

<p>Filled symbols denote clinically affected individuals with both hypogonadism and anosmia (or hyposmia). Half-filled symbols denote individuals with either anosmia only (right black part) or hypogonadism only (left black part). Genotypes, if available, are indicated below. The symbol + denotes normal allele, and fs stands for frameshift mutation. In several pedigrees the mutation is associated with varying phenotypes. Notably, in family A the disease apparently segregates according to a semi-dominant mode of transmission. The schematic representation of PROKR2 shows the locations of the nine missense mutations found in familial and non-familial KS cases, with respect to the putative N-terminal (N ter), C-terminal (C ter), extracellular loop (e1-e3), intracellular loop (i1-i3), and transmembrane (T1–T7) domains [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0020175#pgen-0020175-b013" target="_blank">13</a>] of this G protein-coupled receptor.</p

Table1_Combining globally search for a regular expression and print matching lines with bibliographic monitoring of genomic database improves diagnosis.DOCX

Introduction: Exome sequencing has a diagnostic yield ranging from 25% to 70% in rare diseases and regularly implicates genes in novel disorders. Retrospective data reanalysis has demonstrated strong efficacy in improving diagnosis, but poses organizational difficulties for clinical laboratories.Patients and methods: We applied a reanalysis strategy based on intensive prospective bibliographic monitoring along with direct application of the GREP command-line tool (to “globally search for a regular expression and print matching lines”) in a large ES database. For 18 months, we submitted the same five keywords of interest [(intellectual disability, (neuro)developmental delay, and (neuro)developmental disorder)] to PubMed on a daily basis to identify recently published novel disease–gene associations or new phenotypes in genes already implicated in human pathology. We used the Linux GREP tool and an in-house script to collect all variants of these genes from our 5,459 exome database.Results: After GREP queries and variant filtration, we identified 128 genes of interest and collected 56 candidate variants from 53 individuals. We confirmed causal diagnosis for 19/128 genes (15%) in 21 individuals and identified variants of unknown significance for 19/128 genes (15%) in 23 individuals. Altogether, GREP queries for only 128 genes over a period of 18 months permitted a causal diagnosis to be established in 21/2875 undiagnosed affected probands (0.7%).Conclusion: The GREP query strategy is efficient and less tedious than complete periodic reanalysis. It is an interesting reanalysis strategy to improve diagnosis.</p

Table2_Combining globally search for a regular expression and print matching lines with bibliographic monitoring of genomic database improves diagnosis.XLSX

Introduction: Exome sequencing has a diagnostic yield ranging from 25% to 70% in rare diseases and regularly implicates genes in novel disorders. Retrospective data reanalysis has demonstrated strong efficacy in improving diagnosis, but poses organizational difficulties for clinical laboratories.Patients and methods: We applied a reanalysis strategy based on intensive prospective bibliographic monitoring along with direct application of the GREP command-line tool (to “globally search for a regular expression and print matching lines”) in a large ES database. For 18 months, we submitted the same five keywords of interest [(intellectual disability, (neuro)developmental delay, and (neuro)developmental disorder)] to PubMed on a daily basis to identify recently published novel disease–gene associations or new phenotypes in genes already implicated in human pathology. We used the Linux GREP tool and an in-house script to collect all variants of these genes from our 5,459 exome database.Results: After GREP queries and variant filtration, we identified 128 genes of interest and collected 56 candidate variants from 53 individuals. We confirmed causal diagnosis for 19/128 genes (15%) in 21 individuals and identified variants of unknown significance for 19/128 genes (15%) in 23 individuals. Altogether, GREP queries for only 128 genes over a period of 18 months permitted a causal diagnosis to be established in 21/2875 undiagnosed affected probands (0.7%).Conclusion: The GREP query strategy is efficient and less tedious than complete periodic reanalysis. It is an interesting reanalysis strategy to improve diagnosis.</p

DataSheet1_The different clinical facets of SYN1-related neurodevelopmental disorders.PDF

Synapsin-I (SYN1) is a presynaptic phosphoprotein crucial for synaptogenesis and synaptic plasticity. Pathogenic SYN1 variants are associated with variable X-linked neurodevelopmental disorders mainly affecting males. In this study, we expand on the clinical and molecular spectrum of the SYN1-related neurodevelopmental disorders by describing 31 novel individuals harboring 22 different SYN1 variants. We analyzed newly identified as well as previously reported individuals in order to define the frequency of key features associated with these disorders. Specifically, behavioral disturbances such as autism spectrum disorder or attention deficit hyperactivity disorder are observed in 91% of the individuals, epilepsy in 82%, intellectual disability in 77%, and developmental delay in 70%. Seizure types mainly include tonic-clonic or focal seizures with impaired awareness. The presence of reflex seizures is one of the most representative clinical manifestations related to SYN1. In more than half of the cases, seizures are triggered by contact with water, but other triggers are also frequently reported, including rubbing with a towel, fever, toothbrushing, fingernail clipping, falling asleep, and watching others showering or bathing. We additionally describe hyperpnea, emotion, lighting, using a stroboscope, digestive troubles, and defecation as possible triggers in individuals with SYN1 variants. The molecular spectrum of SYN1 variants is broad and encompasses truncating variants (frameshift, nonsense, splicing and start-loss variants) as well as non-truncating variants (missense substitutions and in-frame duplications). Genotype-phenotype correlation revealed that epileptic phenotypes are enriched in individuals with truncating variants. Furthermore, we could show for the first time that individuals with early seizures onset tend to present with severe-to-profound intellectual disability, hence highlighting the existence of an association between early seizure onset and more severe impairment of cognitive functions. Altogether, we present a detailed clinical description of the largest series of individuals with SYN1 variants reported so far and provide the first genotype-phenotype correlations for this gene. A timely molecular diagnosis and genetic counseling are cardinal for appropriate patient management and treatment.</p

Table1_The different clinical facets of SYN1-related neurodevelopmental disorders.xlsx

Synapsin-I (SYN1) is a presynaptic phosphoprotein crucial for synaptogenesis and synaptic plasticity. Pathogenic SYN1 variants are associated with variable X-linked neurodevelopmental disorders mainly affecting males. In this study, we expand on the clinical and molecular spectrum of the SYN1-related neurodevelopmental disorders by describing 31 novel individuals harboring 22 different SYN1 variants. We analyzed newly identified as well as previously reported individuals in order to define the frequency of key features associated with these disorders. Specifically, behavioral disturbances such as autism spectrum disorder or attention deficit hyperactivity disorder are observed in 91% of the individuals, epilepsy in 82%, intellectual disability in 77%, and developmental delay in 70%. Seizure types mainly include tonic-clonic or focal seizures with impaired awareness. The presence of reflex seizures is one of the most representative clinical manifestations related to SYN1. In more than half of the cases, seizures are triggered by contact with water, but other triggers are also frequently reported, including rubbing with a towel, fever, toothbrushing, fingernail clipping, falling asleep, and watching others showering or bathing. We additionally describe hyperpnea, emotion, lighting, using a stroboscope, digestive troubles, and defecation as possible triggers in individuals with SYN1 variants. The molecular spectrum of SYN1 variants is broad and encompasses truncating variants (frameshift, nonsense, splicing and start-loss variants) as well as non-truncating variants (missense substitutions and in-frame duplications). Genotype-phenotype correlation revealed that epileptic phenotypes are enriched in individuals with truncating variants. Furthermore, we could show for the first time that individuals with early seizures onset tend to present with severe-to-profound intellectual disability, hence highlighting the existence of an association between early seizure onset and more severe impairment of cognitive functions. Altogether, we present a detailed clinical description of the largest series of individuals with SYN1 variants reported so far and provide the first genotype-phenotype correlations for this gene. A timely molecular diagnosis and genetic counseling are cardinal for appropriate patient management and treatment.</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

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

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

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 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