developmental delay Dotaz Zobrazit nápovědu
We report two unrelated patients with overlapping chromosome 2q13 deletions (patient 1 in chr2:111415137-113194067 bp and patient 2 in chr2:110980342-113007823 bp, hg 19). Patient 1 presents with developmental delay, microcephaly and mild dysmorphic facial features, and patient 2 with autism spectrum disorder, borderline cognitive abilities, deficits in attention and executive functions and mild dysmorphic facial features. The mother and maternal grandmother of patient 1 were healthy carriers of the deletion. Previously, 2q13 deletions were reported in 27 patients, and the interpretation of its clinical significance varied. Our findings support that the 2q13 deletion is associated with a developmental delay syndrome manifesting with variable expressivity and reduced penetrance which poses a challenge for genetic counselling as well as the clinical recognition of 2q13 deletion patients.
- Klíčová slova
- 2q13 deletion, BCL2L11, Developmental delay, FBLN7, Facial dysmorphism, TMEM87B, aCGH,
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
Developmental delay is often a predictor of mental retardation (MR) or autism, two relatively frequent developmental disorders severely affecting intellectual and social functioning. The causes of these conditions remain unknown in most patients. They have a strong genetic component, but the specific genetic defects can only be identified in a fraction of patients. Recent developments in genomics supported the establishment of the causal link between copy number variants in the genomes of some patients and their affection. One of the techniques suitable for this analysis is array comparative genome hybridization, which can be used both for detailed mapping of chromosome rearrangements identified by classical cytogenetics and for the identification of novel submicroscopic gains or losses of genetic material. We illustrate the power of this approach in two patients. Patient 1 had a cytogenetically visible deletion of chromosome X and the molecular analysis was used to specify the gene content of the deletion and the prognosis of the child. Patient 2 had a seemingly normal karyotype and the analysis revealed a small recurrent deletion of chromosome 1 likely to be responsible for his phenotype. However, the genetic dissection of MR and autism is complicated by high heterogeneity of the genetic aberrations among patients and by broad variability of phenotypic effects of individual genetic defects.
- MeSH
- chromozomální delece * MeSH
- dítě MeSH
- genetické nemoci vázané na chromozom X genetika MeSH
- genom lidský * MeSH
- lidé MeSH
- lidské chromozomy X genetika MeSH
- lidské chromozomy, pár 1 genetika MeSH
- novorozenec MeSH
- předškolní dítě MeSH
- srovnávací genomová hybridizace * MeSH
- vývojové poruchy u dětí genetika MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- předškolní dítě MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem 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
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
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
Mutations that alter signaling of RAS/MAPK-family proteins give rise to a group of Mendelian diseases known as RASopathies. However, among RASopathies, the matrix of genotype-phenotype relationships is still incomplete, in part because there are many RAS-related proteins and in part because the phenotypic consequences may be variable and/or pleiotropic. Here, we describe a cohort of ten cases, drawn from six clinical sites and over 16,000 sequenced probands, with de novo protein-altering variation in RALA, a RAS-like small GTPase. All probands present with speech and motor delays, and most have intellectual disability, low weight, short stature, and facial dysmorphism. The observed rate of de novo RALA variants in affected probands is significantly higher (p = 4.93 x 10(-11)) than expected from the estimated random mutation rate. Further, all de novo variants described here affect residues within the GTP/GDP-binding region of RALA; in fact, six alleles arose at only two codons, Val25 and Lys128. The affected residues are highly conserved across both RAL- and RAS-family genes, are devoid of variation in large human population datasets, and several are homologous to positions at which disease-associated variants have been observed in other GTPase genes. We directly assayed GTP hydrolysis and RALA effector-protein binding of the observed variants, and found that all but one tested variant significantly reduced both activities compared to wild-type. The one exception, S157A, reduced GTP hydrolysis but significantly increased RALA-effector binding, an observation similar to that seen for oncogenic RAS variants. These results show the power of data sharing for the interpretation and analysis of rare variation, expand the spectrum of molecular causes of developmental disability to include RALA, and provide additional insight into the pathogenesis of human disease caused by mutations in small GTPases.
- MeSH
- faciální stigmatizace MeSH
- fenotyp MeSH
- genotyp MeSH
- guanosindifosfát metabolismus MeSH
- guanosintrifosfát metabolismus MeSH
- interakční proteinové domény a motivy genetika MeSH
- konformace proteinů MeSH
- lidé MeSH
- mentální retardace genetika MeSH
- missense mutace MeSH
- mitochondriální proteiny chemie genetika MeSH
- molekulární modely MeSH
- mutace * MeSH
- Ral proteiny vázající GTP chemie genetika MeSH
- Ras proteiny chemie genetika MeSH
- vývojové poruchy u dětí genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- guanosindifosfát MeSH
- guanosintrifosfát MeSH
- mitochondriální proteiny MeSH
- RAB40AL protein, human MeSH Prohlížeč
- Ral proteiny vázající GTP MeSH
- RALA protein, human MeSH Prohlížeč
- Ras proteiny MeSH
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
Like all auditory evoked potentials, the cortical auditory evoked potentials are nonspecific for the disease, but they provide information about the auditory system function. It appears that the cortical auditory potentials can be used to study the disorders of speech comprehension and their pathology is related to the role of the temporal processing of the auditory stimuli. Cortical auditory potentials were studied in children with developmental dysphasia (DD) to examine maturation of the central auditory pathways. Study 1 (group of 6-7 yr. old children with DD): the responses to verbal stimuli (P3 waves) were recorded with prolonged latencies from the left dominant hemisphere. Study 2: the latencies of P2 waves (to tonal stimuli) were being shortened within age-comparison of groups of 6-7 and 9-10 yr. old children with DD. Great variability in P2 and P3 latencies, and their prolongation, compared to normal healthy children, reflects functional changes in the central hearing function. Latency differences may be related to a common temporal deficit to be one of the possible underlying factors in developmental dysphasia. The underlying phenomenon may be connected to cortical auditory processing.
- MeSH
- dítě MeSH
- lidé MeSH
- reakční čas MeSH
- sluchové evokované potenciály * MeSH
- vývojové poruchy řeči patofyziologie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This study reports longitudinal follow-up of 300 children with developmental dysphasia. Their expressive disturbances are a manifestation of their auditory decoding impairment. These children were investigated on battery of tests of spoken language, of phonological processing and of different audiometric procedures, in order to register all the information necessary to be able judge the speech-language development. The tests focused on diagnosis of central auditory disorder, confirmed the difficulties in association area in children with developmental dysphasia. In speech perception, the temporal processing is one of the functions necessary for the discrimination of phonemes, and of similar words. Our results confirmed long-term problems of children with developmental dysphasia with central auditory perception disorder.
- MeSH
- dítě MeSH
- elektroencefalografie * MeSH
- epilepsie diagnóza MeSH
- lidé MeSH
- následné studie MeSH
- polysomnografie MeSH
- poruchy polykání diagnóza MeSH
- vývojové poruchy u dětí diagnóza MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH