Microtubule associated proteins (MAPs) are widely expressed in the central nervous system, and have established roles in cell proliferation, myelination, neurite formation, axon specification, outgrowth, dendrite, and synapse formation. We report eleven individuals from seven families harboring predicted pathogenic biallelic, de novo, and heterozygous variants in the NAV3 gene, which encodes the microtubule positive tip protein neuron navigator 3 (NAV3). All affected individuals have intellectual disability (ID), microcephaly, skeletal deformities, ocular anomalies, and behavioral issues. In mouse brain, Nav3 is expressed throughout the nervous system, with more prominent signatures in postmitotic, excitatory, inhibiting, and sensory neurons. When overexpressed in HEK293T and COS7 cells, pathogenic variants impaired NAV3 ability to stabilize microtubules. Further, knocking-down nav3 in zebrafish led to severe morphological defects, microcephaly, impaired neuronal growth, and behavioral impairment, which were rescued with co-injection of WT NAV3 mRNA and not by transcripts encoding the pathogenic variants. Our findings establish the role of NAV3 in neurodevelopmental disorders, and reveal its involvement in neuronal morphogenesis, and neuromuscular responses.

• MeSH
• Cercopithecus aethiops MeSH
• COS buňky MeSH
• dánio pruhované genetika   MeSH
• dítě MeSH
• HEK293 buňky MeSH
• lidé MeSH
• mentální retardace * genetika   MeSH
• mikrocefalie * genetika   patologie   MeSH
• myši MeSH
• neurony metabolismus   patologie   MeSH
• předškolní dítě MeSH
• proteiny asociované s mikrotubuly genetika   metabolismus   MeSH
• proteiny nervové tkáně genetika   metabolismus   MeSH
• vývojové poruchy u dětí * genetika   MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• NAV3 protein, human MeSH Prohlížeč
• proteiny asociované s mikrotubuly MeSH
• proteiny nervové tkáně MeSH

• MeSH
• dítě MeSH
• faciální stigmatizace MeSH
• lidé MeSH
• lipomatóza * genetika   MeSH
• mutace MeSH
• receptory cytoplazmatické a nukleární genetika   MeSH
• represorové proteiny genetika   MeSH
• vývojové poruchy u dětí * genetika   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• receptory cytoplazmatické a nukleární MeSH
• represorové proteiny MeSH
• TBL1XR1 protein, human MeSH Prohlížeč

Almost half of all individuals affected by intellectual disability (ID) remain undiagnosed. In the Solve-RD project, exome sequencing (ES) datasets from unresolved individuals with (syndromic) ID (n = 1,472 probands) are systematically reanalyzed, starting from raw sequencing files, followed by genome-wide variant calling and new data interpretation. This strategy led to the identification of a disease-causing de novo missense variant in TUBB3 in a girl with severe developmental delay, secondary microcephaly, brain imaging abnormalities, high hypermetropia, strabismus and short stature. Interestingly, the TUBB3 variant could only be identified through reanalysis of ES data using a genome-wide variant calling approach, despite being located in protein coding sequence. More detailed analysis revealed that the position of the variant within exon 5 of TUBB3 was not targeted by the enrichment kit, although consistent high-quality coverage was obtained at this position, resulting from nearby targets that provide off-target coverage. In the initial analysis, variant calling was restricted to the exon targets ± 200 bases, allowing the variant to escape detection by the variant calling algorithm. This phenomenon may potentially occur more often, as we determined that 36 established ID genes have robust off-target coverage in coding sequence. Moreover, within these regions, for 17 genes (likely) pathogenic variants have been identified before. Therefore, this clinical report highlights that, although compute-intensive, performing genome-wide variant calling instead of target-based calling may lead to the detection of diagnostically relevant variants that would otherwise remain unnoticed.

• Klíčová slova
• ERN ITHACA, Exome sequencing, Genome-wide variant calling, Solve-RD, TUBB3,
• MeSH
• lidé MeSH
• mentální retardace genetika   MeSH
• mikrocefalie genetika   MeSH
• missense mutace MeSH
• mladiství MeSH
• mozek abnormality   MeSH
• obličej abnormality   MeSH
• sekvenování exomu MeSH
• strabismus genetika   MeSH
• tubulin genetika   MeSH
• vývojové poruchy u dětí genetika   MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• TUBB3 protein, human MeSH Prohlížeč
• tubulin MeSH

Developmental and epileptic encephalopathies (DEEs) are a group of severe epilepsies that are characterized by seizures and developmental delay. DEEs are primarily attributed to genetic causes and an increasing number of cases have been correlated with variants in ion channel genes. In this study, we report a child with an early severe DEE. Whole exome sequencing showed a de novo heterozygous variant (c.4873-4881 duplication) in the SCN8A gene and an inherited heterozygous variant (c.952G > A) in the CACNA1H gene encoding for Nav1.6 voltage-gated sodium and Cav3.2 voltage-gated calcium channels, respectively. In vitro functional analysis of human Nav1.6 and Cav3.2 channel variants revealed mild but significant alterations of their gating properties that were in general consistent with a gain- and loss-of-channel function, respectively. Although additional studies will be required to confirm the actual pathogenic involvement of SCN8A and CACNA1H, these findings add to the notion that rare ion channel variants may contribute to the etiology of DEEs.

• Klíčová slova
• CACNA1H, Calcium channel, Cav3.2 channel, Channelopathy, Encephalopathy, Epilepsy, Ion channels, Nav1.6 channel, SCN8A, Sodium channel,
• MeSH
• aktivační mutace MeSH
• bodová mutace MeSH
• duplikace genu MeSH
• epilepsie tonicko-klonická genetika   MeSH
• gating iontového kanálu genetika   fyziologie   MeSH
• genetická predispozice k nemoci MeSH
• lidé MeSH
• missense mutace MeSH
• mnohočetné abnormality genetika   MeSH
• napěťově řízený sodíkový kanál, typ 6 genetika   fyziologie   MeSH
• novorozenec MeSH
• refrakterní epilepsie genetika   MeSH
• rodokmen MeSH
• skolióza genetika   MeSH
• vápníkové kanály - typ T genetika   fyziologie   MeSH
• vývojové poruchy u dětí genetika   MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• CACNA1H protein, human MeSH Prohlížeč
• napěťově řízený sodíkový kanál, typ 6 MeSH
• SCN8A protein, human MeSH Prohlížeč
• vápníkové kanály - typ T MeSH

The forkhead transcription factor FOXE3 is critical for vertebrate eye development. Recessive and dominant variants cause human ocular disease but the full range of phenotypes and mechanisms of action for the two classes of variants are unknown. We identified FOXE3 variants in individuals with congenital eye malformations and carried out in vitro functional analysis on selected alleles. Sixteen new recessive and dominant families, including six novel variants, were identified. Analysis of new and previously reported genetic and clinical data demonstrated a broad phenotypic range with an overlap between recessive and dominant disease. Most families with recessive alleles, composed of truncating and forkhead-domain missense variants, had severe corneal opacity (90%; sclerocornea in 47%), aphakia (83%) and microphthalmia (80%), but some had milder features including isolated cataract. The phenotype was most variable for recessive missense variants, suggesting that the functional consequences may be highly dependent on the type of amino acid substitution and its position. When assessed, aniridia or iris hypoplasia were noted in 89% and optic nerve anomalies in 60% of recessive cases, indicating that these defects are also common and may be underrecognized. In dominant pedigrees, caused by extension variants, normal eye size (96%), cataracts (99%) and variable anterior segment anomalies were seen in most, but some individuals had microphthalmia, aphakia or sclerocornea, more typical of recessive disease. Functional studies identified variable effects on the protein stability, DNA binding, nuclear localization and transcriptional activity for recessive FOXE3 variants, whereas dominant alleles showed severe impairment in all areas and dominant-negative characteristics.

• MeSH
• abnormality očí enzymologie   genetika   MeSH
• alely MeSH
• dítě MeSH
• fenotyp MeSH
• forkhead transkripční faktory genetika   metabolismus   MeSH
• katarakta genetika   MeSH
• lidé MeSH
• mladiství MeSH
• mutace MeSH
• oči embryologie   růst a vývoj   MeSH
• rodokmen MeSH
• vývojové poruchy u dětí genetika   MeSH
• zákal rohovky genetika   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• forkhead transkripční faktory MeSH
• FOXE3 protein, human MeSH Prohlížeč

BACKGROUND: Recent studies suggest that duplication of the 9p24.3 chromosomal locus, which includes the DOCK8 and KANK1 genes, is associated with autism spectrum disorders (ASD), intellectual disability/developmental delay (ID/DD), learning problems, language disorders, hyperactivity, and epilepsy. Correlation between this duplication and the carrier phenotype needs further discussion. METHODS: In this study, three unrelated patients with ID/DD and ASD underwent SNP aCGH and MLPA testing. Similarities in the phenotypes of patients with 9p24.3, 15q11.2, and 16p11.2 duplications were also observed. RESULTS: All patients with ID/DD and ASD carried the 9p24.3 duplication and showed intragenic duplication of DOCK8. Additionally, two patients had ADHD, one was hearing impaired and obese, and one had macrocephaly. Inheritance of the 9p24.3 duplication was confirmed in one patient and his sibling. In one patient KANK1 was duplicated along with DOCK8. Carriers of 9p24.3, 15q11.2, and 16p11.2 duplications showed several phenotypic similarities, with ID/DD more strongly associated with duplication of 9p24.3 than of 15q11.2 and 16p11.2. CONCLUSION: We concluded that 9p24.3 is a likely cause of ASD and ID/DD, especially in cases of DOCK8 intragenic duplication. DOCK8 is a likely causative gene, and KANK1 aberrations a modulator, of the clinical phenotype observed. Other modulators were not excluded.

• Klíčová slova
• 15q11.2 duplication, 16p11.2 duplication, 9p24.3 duplication, developmental delay,
• MeSH
• adaptorové proteiny signální transdukční genetika   MeSH
• chromozomální poruchy genetika   patologie   MeSH
• cytoskeletální proteiny genetika   MeSH
• dítě MeSH
• duplikace chromozomů * MeSH
• fenotyp * MeSH
• lidé MeSH
• lidské chromozomy, pár 9 genetika   MeSH
• předškolní dítě MeSH
• výměnné faktory guaninnukleotidů genetika   MeSH
• vývojové poruchy u dětí genetika   patologie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• cytoskeletální proteiny MeSH
• DOCK8 protein, human MeSH Prohlížeč
• KANK1 protein, human MeSH Prohlížeč
• výměnné faktory guaninnukleotidů MeSH

In pleiotropic diseases, multiple organ systems are affected causing a variety of clinical manifestations. Here, we report a pleiotropic disorder with a unique constellation of neurological, endocrine, exocrine, and haematological findings that is caused by biallelic MADD variants. MADD, the mitogen-activated protein kinase (MAPK) activating death domain protein, regulates various cellular functions, such as vesicle trafficking, activity of the Rab3 and Rab27 small GTPases, tumour necrosis factor-α (TNF-α)-induced signalling and prevention of cell death. Through national collaboration and GeneMatcher, we collected 23 patients with 21 different pathogenic MADD variants identified by next-generation sequencing. We clinically evaluated the series of patients and categorized the phenotypes in two groups. Group 1 consists of 14 patients with severe developmental delay, endo- and exocrine dysfunction, impairment of the sensory and autonomic nervous system, and haematological anomalies. The clinical course during the first years of life can be potentially fatal. The nine patients in Group 2 have a predominant neurological phenotype comprising mild-to-severe developmental delay, hypotonia, speech impairment, and seizures. Analysis of mRNA revealed multiple aberrant MADD transcripts in two patient-derived fibroblast cell lines. Relative quantification of MADD mRNA and protein in fibroblasts of five affected individuals showed a drastic reduction or loss of MADD. We conducted functional tests to determine the impact of the variants on different pathways. Treatment of patient-derived fibroblasts with TNF-α resulted in reduced phosphorylation of the extracellular signal-regulated kinases 1 and 2, enhanced activation of the pro-apoptotic enzymes caspase-3 and -7 and increased apoptosis compared to control cells. We analysed internalization of epidermal growth factor in patient cells and identified a defect in endocytosis of epidermal growth factor. We conclude that MADD deficiency underlies multiple cellular defects that can be attributed to alterations of TNF-α-dependent signalling pathways and defects in vesicular trafficking. Our data highlight the multifaceted role of MADD as a signalling molecule in different organs and reveal its physiological role in regulating the function of the sensory and autonomic nervous system and endo- and exocrine glands.

• Klíčová slova
• DENN, HSAN, intellectual disability, multisystem, whole-exome sequencing,
• MeSH
• fenotyp MeSH
• lidé MeSH
• mutace MeSH
• nemoci nervového systému genetika   MeSH
• signální adaptorové proteiny receptorové domény smrti genetika   MeSH
• signální transdukce genetika   MeSH
• transport proteinů genetika   MeSH
• výměnné faktory guaninnukleotidů genetika   MeSH
• vývojové poruchy u dětí genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• MADD protein, human MeSH Prohlížeč
• signální adaptorové proteiny receptorové domény smrti MeSH
• výměnné faktory guaninnukleotidů MeSH

PURPOSE: The purpose of this study was to expand the genetic architecture of neurodevelopmental disorders, and to characterize the clinical features of a novel cohort of affected individuals with variants in ZNF142, a C2H2 domain-containing transcription factor. METHODS: Four independent research centers used exome sequencing to elucidate the genetic basis of neurodevelopmental phenotypes in four unrelated families. Following bioinformatic filtering, query of control data sets, and secondary variant confirmation, we aggregated findings using an online data sharing platform. We performed in-depth clinical phenotyping in all affected individuals. RESULTS: We identified seven affected females in four pedigrees with likely pathogenic variants in ZNF142 that segregate with recessive disease. Affected cases in three families harbor either nonsense or frameshifting likely pathogenic variants predicted to undergo nonsense mediated decay. One additional trio bears ultrarare missense variants in conserved regions of ZNF142 that are predicted to be damaging to protein function. We performed clinical comparisons across our cohort and noted consistent presence of intellectual disability and speech impairment, with variable manifestation of seizures, tremor, and dystonia. CONCLUSION: Our aggregate data support a role for ZNF142 in nervous system development and add to the emergent list of zinc finger proteins that contribute to neurocognitive disorders.

• Klíčová slova
• ataxia, childhood apraxia of speech, developmental delay, dolichocephaly, homozygosity mapping,
• MeSH
• dítě MeSH
• dospělí MeSH
• dystonie genetika   MeSH
• fenotyp MeSH
• kohortové studie MeSH
• lidé MeSH
• mentální retardace genetika   MeSH
• missense mutace MeSH
• mladiství MeSH
• mutace MeSH
• neurovývojové poruchy genetika   MeSH
• poruchy řeči genetika   MeSH
• rodina MeSH
• rodokmen MeSH
• sekvenování exomu MeSH
• trans-aktivátory genetika   metabolismus   MeSH
• výpočetní biologie metody   MeSH
• vývojové poruchy u dětí genetika   MeSH
• záchvaty genetika   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• trans-aktivátory MeSH
• ZNF143 protein, human MeSH Prohlížeč

BACKGROUND: Chromosomal microarray analysis has been shown to be a valuable and cost effective assay for elucidating copy number variants (CNVs) in children with intellectual disability and developmental delay (ID/DD). METHODS: In our study, we performed array-based comparative genomic hybridization (array-CGH) analysis using oligonucleotide-based platforms in 542 Czech patients with ID/DD, autism spectrum disorders and multiple congenital abnormalities. Prior to the array-CGH analysis, all the patients were first examined karyotypically using G-banding. The presence of CNVs and their putative derivation was confirmed using fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA) and predominantly relative quantitative polymerase chain reaction (qPCR). RESULTS: In total, 5.9% (32/542) patients were positive for karyotypic abnormalities. Pathogenic/likely pathogenic CNVs were identified in 17.7% of them (96/542), variants of uncertain significance (VOUS) were detected in 4.8% (26/542) and likely benign CNVs in 9.2% of cases (50/542). We identified 6.6% (36/542) patients with known recurrent microdeletion (24 cases) and microduplication (12 cases) syndromes, as well as 4.8% (26/542) patients with non-recurrent rare microdeletions (21 cases) and microduplications (5 cases). In the group of patients with submicroscopic pathogenic/likely pathogenic CNVs (13.3%; 68/510) we identified 91.2% (62/68) patients with one CNV, 5.9% (4/68) patients with two likely independent CNVs and 2.9% (2/68) patients with two CNVs resulting from cryptic unbalanced translocations. Of all detected CNVs, 21% (31/147) had a de novo origin, 51% (75/147) were inherited and 28% (41/147) of unknown origin. In our cohort pathogenic/likely pathogenic microdeletions were more frequent than microduplications (69%; 51/74 vs. 31%; 23/74) ranging in size from 0.395 Mb to 10.676 Mb (microdeletions) and 0.544 Mb to 8.156 Mb (microduplications), but their sizes were not significantly different (P = 0.83). The pathogenic/likely pathogenic CNVs (median 2.663 Mb) were significantly larger than benign CNVs (median 0.394 Mb) (P < 0.00001) and likewise the pathogenic/likely pathogenic CNVs (median 2.663 Mb) were significantly larger in size than VOUS (median 0.469 Mb) (P < 0.00001). CONCLUSIONS: Our results confirm the benefit of array-CGH in the current clinical genetic diagnostics leading to identification of the genetic cause of ID/DD in affected children.

• Klíčová slova
• Array-CGH, CNV, Developmental delay, Intellectual disability, Microdeletion, Microduplication,
• MeSH
• dítě MeSH
• kohortové studie MeSH
• kojenec MeSH
• lidé MeSH
• mentální retardace genetika   MeSH
• mladiství MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů * MeSH
• srovnávací genomová hybridizace * MeSH
• variabilita počtu kopií segmentů DNA * MeSH
• vývojové poruchy u dětí genetika   MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

De novo sequence variants, including truncating and splicing variants, in the additional sex‑combs like 3 gene (ASXL3) have been described as the cause of Bainbridge‑Ropers syndrome (BRS). This pathology is characterized by delayed psychomotor development, severe intellectual disability, growth delay, hypotonia and facial dimorphism. The present study reports a case of a girl (born in 2013) with severe global developmental delay, central hypotonia, microcephaly and poor speech. The proband was examined using a multi‑step molecular diagnostics algorithm, including karyotype and array‑comparative genomic hybridization analysis, with negative results. Therefore, the proband and her unaffected parents were enrolled for a pilot study using targeted next‑generation sequencing technology (NGS) with gene panel ClearSeq Inherited DiseaseXT and subsequent validation by Sanger sequencing. A novel de novo heterozygous frameshift variant in the ASXL3 gene (c.3006delT, p.R1004Efs*21), predicted to result in a premature termination codon, was identified. In conclusion, the present study demonstrated that targeted NGS using a suitable, gene‑rich panel may provide a conclusive molecular genetics diagnosis in children with severe global developmental delays.

• MeSH
• dítě MeSH
• lidé MeSH
• mikrocefalie genetika   MeSH
• pilotní projekty MeSH
• poruchy řeči genetika   MeSH
• posunová mutace MeSH
• rodokmen MeSH
• svalová hypotonie genetika   MeSH
• transkripční faktory genetika   MeSH
• vývojové poruchy u dětí genetika   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• ASXL3 protein, human MeSH Prohlížeč
• transkripční faktory MeSH