Schematic illustration of the cellular interference mechanism associated with <i>PCDH19</i> mutations.

<p>A) In normal individuals, characterized by a homogeneous population of <i>PCDH19</i>-positive cells, neurons are able to form normal neuronal networks; B) In mutated male patients, hemizygosity leads to a homogeneous population of <i>PCDH19</i>-negative cells; in this condition, neurons preserve the ability to form normal neuronal networks; C) In heterozygous mutated females, random X inactivation leads to the co-existence of two <i>PCDH19</i>-positive and <i>PCDH19</i>-negative cell populations. These two cell populations cause divergent cell sorting and migration (due to attractive or repulsive interactions) and lead to abnormal neuronal networks. Somatic mosaicism in mutated males gives rise to the same pathological situation. The precise mechanisms by which the neuronal networks are altered are still unknown.</p

Detection of 9 different point mutations of <i>PCDH19</i> in 11 female patients by direct sequencing.

<p>A) Sequence electropherograms of the mutations and the missense variant (c.3319C>G/p.Arg1107Gly) identified in association with the c.859G>T/p.Glu287X nonsense mutation. The mutation nomenclature is based on the <i>PCDH19</i> transcript reference EF676096. Nucleotides are numbered according to the cDNA with +1 corresponding to the A of the ATG translation initiation codon in the reference sequence, according to the journal guidelines (<a href="http://www.hgvs.org/mutnomen" target="_blank">www.hgvs.org/mutnomen</a>). B) Alignment of the regions surrounding the mutations (indicated by an arrow) in orthologous and paralogous proteins, showing the high conservation of each affected amino-acid in vertebrates and in the delta protocadherin paralogous genes.</p

Clinical characteristics of patients with <i>PCDH19</i> mutations.

<p>2*: patient N 06 1258 is the sister of patient N 06 1257 (index case); PMD = psychomotor development, Nl = normal, F = febrile, unit = unilateral, GTC = generalized tonic-clonic, W-S = words-sentences, abs = absent, AED = anti epileptic drugs.</p

Identification of a deletion encompassing <i>PCDH19</i> in a male patient.

<p>A) Identification of a hemizygous Xq22.1 deletion with a 370 K SNP microarray (Illumina): Y-axes represent Log R ratio (above) and B allele frequency (below); the X-axis indicates the position on the X chromosome. The red line (log R ratio profile) corresponds to the median smoothing series (Beadstudio). B) Analysis of the patient and his mother with CGH microarrays (Nimblegen), showing that the deletion occurred de novo. Indicated genomic positions are based upon the Ensembl Genome Browser. Black horizontal bars (below) represent the gene (<i>PCDH19</i>) and pseudogenes comprised in the deleted region.</p

FISH analysis of the <i>PCDH19</i> deletion in the male patient showing somatic mosaicism in fibroblasts.

<p>(A) Absence of the specific Xq22.1 probe site on metaphase chromosomes in peripheral blood lymphocytes (PBL); (B) In fibroblasts, presence of one hybridization spot in 53% of the cells and absence of signal in the remaining 47%; C) and D) FISH analysis on PBL (C) and fibroblasts (D) of a female control. <i>PCDH19</i>-specific signals (red) are indicated by arrowheads. Magnification ×1000.</p

Pedigrees of the families and segregation analysis of the <i>PCDH19</i> deletion and point mutations.

<p>del/+, m/+ or v/+ denote individuals heterozygous for the deletion, mutation or variant, respectively; +/+ denotes individuals carrying homozygous wild-type alleles. Squares represent males, circles females; filled black symbols: patients diagnosed as having Dravet syndrome; right black half: Cognitive delay or impairment; left grey half: adolescence-onset idiopathic epilepsy. Dots in the middle of the squares indicate unaffected mutation carriers. The arrows indicate the index cases.</p

Garland nephrocyte phenotype of <i>hts</i>^<i>null</i> and adducin-αγ rescue mutants.

<p>(A) Kirre and Pyd localization in <i>hts</i>^<i>null</i> and rescue mutant garland nephrocytes. Dissected nephrocytes of the indicated genotypes were stained for Kirre (red) and Pyd, corresponding to Neph1 and ZO-1 in vertebrates, (blue). Arrowheads show areas of cell fusion. Scale bar: 10μm. (B) Quantification of nephrocytes showing a continuous Kirre staining using >9 samples/genotype from 3 independent experiments. Statistical analysis was performed with Kruskal-Wallis with Dunn’s post-test. ns, non significant, *p<0.05, ***p<0.001 (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007386#pgen.1007386.s009" target="_blank">S1 Table</a> for details on transgenic flies). (C) Pericardial nephrocytes in adducin-αγ WT and E559Q rescue and control adult flies at 15 days post-eclosion were stained for the differentiation markers Kirre (red) and Pyd (blue). Note that <i>hts</i>^<i>null</i> is lethal at this stage. Scale bar: 30μm. (D) Quantification of the number of pericardial nephrocytes from n>8 samples/genotype in 3 independent experiments. Statistical analysis was performed using one-way ANOVA with Bonferroni’s post-test. ns, non significant (See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007386#pgen.1007386.s009" target="_blank">S1 Table</a> for details on transgenic flies).</p

Pathogenic genetic variants identified in affected individuals with overlapping syndromes.

<p>Pathogenic genetic variants identified in affected individuals with overlapping syndromes.</p

Effect of Gcn5 F304S mutation on <i>Drosophila</i> heart function.

<p>(A-C) M-mode kymographs of 1 day old beating hearts of control flies (<i>yw/Df(3L)</i>; A) and Gcn5^<i>null</i> flies rescued with Gcn5 WT (B) or Gcn5 F304S (C). Scale bar: 1 second. (D-H) High-speed movies of beating hearts were analysed using semi-automated Optical Heartbeat Analysis [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007386#pgen.1007386.ref046" target="_blank">46</a>]. For quantification, 8–19 flies were analyzed. Statistical analysis was performed using one-way ANOVA and Tukey’s multiple comparison for all parameters except arrhythmia index (H), which was analysed using Mann-Whitney-Wilcoxon. For all panels: ns, non significant, *p<0.05 **p<0.01, ***p<0.001, ****p<0.0001 (see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007386#pgen.1007386.s009" target="_blank">S1 Table</a> for details on transgenic flies).</p

Effect of adducin-αγ E559Q on <i>Drosophila</i> heart function.

<p>(A-C) M-mode of beating 2-week-old control (<i>yw/Df(2R);</i> A), adducin-αγ WT (B) and adducin-αγ E559Q (C) rescue hearts. Scale bar: 1 second. (D-H) High-speed movies of beating adducin-αγ WT, adducin-αγ E559Q rescue and control hearts were analysed using semi-automated Optical Heartbeat Analysis [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007386#pgen.1007386.ref046" target="_blank">46</a>]. For quantification, 8–19 flies were analyzed. Statistical analysis was performed using one-way ANOVA and Tukey’s multiple comparison, except for Arrhythmia index (H; n = 8–19, Mann-Whitney-Wilcoxon). For all panels: ns, non significant, ***p<0.001 (See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007386#pgen.1007386.s009" target="_blank">S1 Table</a> for details on transgenic flies).</p