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1.
Am J Med Genet A ; 179(8): 1543-1546, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31207089

RESUMO

1p36 deletion syndrome is a well-described condition with a recognizable phenotype, including cognitive impairment, seizures, and structural brain anomalies such as periventricular leukomalacia (PVL). In a large series of these individuals by Battaglia et al., "birth history was notable in 50% of the cases for varying degrees of perinatal distress." Given the potential for perinatal distress, seizures and PVL, we questioned if this disorder has clinical overlap with hypoxic ischemic encephalopathy (HIE). We reviewed the medical records of 69 individuals with 1p36 deletion to clarify the perinatal phenotype of this disorder and determine if there is evidence of perinatal distress and/or hypoxic injury. Our data provides evidence that these babies have signs of perinatal distress. The majority (59% term; 75% preterm) needed resuscitation and approximately 18% had cardiac arrest. Most had abnormal brain imaging (84% term; 73% preterm) with abnormal white matter findings in over half of patients. PVL or suggestion of "hypoxic insult" was present in 18% of term and 45% of preterm patients. In conclusion, individuals with 1p36 deletion have evidence of perinatal distress, white matter changes, and seizures, which can mimic HIE but are likely related to their underlying chromosome disorder.

2.
Clin Genet ; 96(3): 246-253, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31090057

RESUMO

Two distinct genomic disorders have been linked to Xq28-gains, namely Xq28-duplications including MECP2 and Int22h1/Int22h2-mediated duplications involving RAB39B. Here, we describe six unrelated patients, five males and one female, with Xq28-gains distal to MECP2 and proximal to the Int22h1/Int22h2 low copy repeats. Comparison with patients carrying overlapping duplications in the literature defined the MidXq28-duplication syndrome featuring intellectual disability, language impairment, structural brain malformations, microcephaly, seizures and minor craniofacial features. The duplications overlapped for 108 kb including FLNA, RPL10 and GDI1 genes, highly expressed in brain and candidates for the neurologic phenotype.

3.
Am J Med Genet A ; 2018 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-30289612

RESUMO

Wolf-Hirschhorn syndrome (WHS) is a rare contiguous gene deletion disorder characterized by distinctive craniofacial features, prenatal/postnatal growth deficiency, intellectual disability, and seizures. Various malformations of internal organs are also seen. Neoplasia has not been documented as a typical feature of WHS. We review the three prior reports of hepatic neoplasia in WHS and add four previously unreported individuals. We propose that, in the context of the rarity of WHS, these seven cases suggest that hepatocellular neoplasia may be a feature of WHS.

4.
Am J Hum Genet ; 103(2): 305-316, 2018 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-30057029

RESUMO

Next-generation sequencing combined with international data sharing has enormously facilitated identification of new disease-associated genes and mutations. This is particularly true for genetically extremely heterogeneous entities such as neurodevelopmental disorders (NDDs). Through exome sequencing and world-wide collaborations, we identified and assembled 20 individuals with de novo variants in FBXO11. They present with mild to severe developmental delay associated with a range of features including short (4/20) or tall (2/20) stature, obesity (5/20), microcephaly (4/19) or macrocephaly (2/19), behavioral problems (17/20), seizures (5/20), cleft lip or palate or bifid uvula (3/20), and minor skeletal anomalies. FBXO11 encodes a member of the F-Box protein family, constituting a subunit of an E3-ubiquitin ligase complex. This complex is involved in ubiquitination and proteasomal degradation and thus in controlling critical biological processes by regulating protein turnover. The identified de novo aberrations comprise two large deletions, ten likely gene disrupting variants, and eight missense variants distributed throughout FBXO11. Structural modeling for missense variants located in the CASH or the Zinc-finger UBR domains suggests destabilization of the protein. This, in combination with the observed spectrum and localization of identified variants and the lack of apparent genotype-phenotype correlations, is compatible with loss of function or haploinsufficiency as an underlying mechanism. We implicate de novo missense and likely gene disrupting variants in FBXO11 in a neurodevelopmental disorder with variable intellectual disability and various other features.

5.
Epilepsy Behav ; 81: 55-61, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29477837

RESUMO

Seizures are present in over 90% of infants and children with Wolf-Hirschhorn syndrome (WHS). When present, they significantly affect quality of life. The goal of this study was to use caregiver reports to describe the comparative efficacies of commonly used antiepileptic medications in a large population of individuals with WHS. A web-based, confidential caregiver survey was developed to capture seizure semiology and a chronologic record of seizure treatments as well as responses to each treatment. Adverse events for each drug were also cataloged. We received 141 complete survey responses (47% response rate) describing the seizures of individuals ranging in age from 4months to 61years (90 females: 51 males). Using the Early Childhood Epilepsy Severity Scale (E-Chess), WHS-associated seizures are demonstrably severe regardless of deletion size. The best-performing antiepileptic drugs (AEDs) for controlling seizures in this cohort were broad spectrum drugs clobazam, levetiracetam, and lamotrigine; whereas, the three commonly used carboxamide class drugs: carbamazepine, phenytoin, and oxcarbazepine, were reported to have little effect on, or even exacerbate, seizures. The carboxamide class drugs, along with phenobarbital and topiramate, were also associated with the highest rate of intolerance due to cooccurrence of adverse events. Levetiracetam, clobazam, and clonazepam demonstrated higher tolerability and comparatively less severe adverse events (Wilcoxon rank sum comparison between performance of levetiracetam and carboxamide class drugs gives a p<0.0001 after multiple comparison adjustment). This is the largest survey to date assessing WHS seizures. This study design is susceptible to possible bias, as the data are largely drawn from caregiver report and investigators had limited access to medical records. Despite this, our data suggest that the genetic etiology of seizures, together with an accurate electroclinical delineation, are important components of drug selection, even in contiguous gene syndromes which may have complex seizure etiologies.

6.
Autism Res ; 10(2): 202-211, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27417655

RESUMO

Common variants contribute significantly to the genetics of autism spectrum disorder (ASD), although the identification of individual risk polymorphisms remains still elusive due to their small effect sizes and limited sample sizes available for association studies. During the last decade several genome-wide association studies (GWAS) have enabled the detection of a few plausible risk variants. The three main studies are family-based and pointed at SEMA5A (rs10513025), MACROD2 (rs4141463) and MSNP1 (rs4307059). In our study we attempted to replicate these GWAS hits using a case-control association study in five European populations of ASD patients and gender-matched controls, all Caucasians. Results showed no association of individual variants with ASD in any of the population groups considered or in the combined European sample. We performed a meta-analysis study across five European populations for rs10513025 (1,904 ASD cases and 2,674 controls), seven European populations for rs4141463 (2,855 ASD cases and 36,177 controls) and five European populations for rs4307059 (2,347 ASD cases and 2,764 controls). The results showed an odds ratio (OR) of 1.05 (95% CI = 0.84-1.32) for rs10513025, 1.0002 (95% CI = 0.93-1.08) for rs4141463 and 1.01 (95% CI = 0.92-1.1) for rs4307059, with no significant P-values (rs10513025, P = 0.73; rs4141463, P = 0.95; rs4307059, P = 0.9). No association was found when we considered either only high functioning autism (HFA), genders separately or only multiplex families. Ongoing GWAS projects with larger ASD cohorts will contribute to clarify the role of common variation in the disorder and will likely identify risk variants of modest effect not detected previously. Autism Res 2017, 10: 202-211. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.


Assuntos
Transtorno do Espectro Autista/genética , Estudo de Associação Genômica Ampla/estatística & dados numéricos , Estudos de Casos e Controles , Europa (Continente) , Feminino , Estudo de Associação Genômica Ampla/métodos , Humanos , Masculino , Reprodutibilidade dos Testes
7.
Am J Med Genet A ; 170(10): 2531-9, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27513709

RESUMO

Previous reports summarized the seizure types occurring in patients with idic(15) syndrome. To better define this issue, we retrospectively analyzed the evolution of electroencephalogram findings and seizures in 35 patients with confirmed idic(15). Epilepsy occurred in 28 patients (80%), with a median age of onset of 3 years 3 months. The initial seizures were infantile spasms associated with a hypsarrhythmic electroencephalogram (nine patients), focal/generalized tonic (seven patients), or atypical absences (eight patients). High doses of oral steroids were given in all nine children with infantile spasms, with remission of seizures and resolution of electroencephalogram abnormalities. Among them, three were seizure free at the time of evaluation, but six later developed Lennox-Gastaut syndrome or Lennox-Gastaut-like syndrome. The eight patients with atypical absences developed Lennox-Gastaut syndrome or Lennox-Gastaut-like syndrome. Epilepsy was well controlled in 32% of the patients; satisfactorily controlled (seizures reduced >75%) in 21.4%; partially controlled (seizures reduced <50%) in 10.7%; and uncontrolled in 32%. One patient was not taking any anti-epileptic drugs by his parents' choice. Fourteen percent were on monotherapy; whereas the other 82% were on polytherapy. Seizures stopped at a median age of 5 years 5 months. The interictal electroencephalogram showed slow/sharp waves, and/or biphasic spikes-polyspikes, spike/wave complexes, and an excess of fast activity mainly over the fronto-temporal areas. Epilepsy is a major clinical challenge in patients with idic(15), associated with a poor prognosis in 55%. Frontal lobe seizures are a novel finding. © 2016 Wiley Periodicals, Inc.


Assuntos
Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/fisiopatologia , Eletroencefalografia , Convulsões/diagnóstico , Adolescente , Adulto , Idade de Início , Anticonvulsivantes/uso terapêutico , Criança , Pré-Escolar , Aberrações Cromossômicas , Transtornos Cromossômicos/genética , Transtornos Cromossômicos/terapia , Cromossomos Humanos Par 15/genética , Terapia Combinada , Hibridização Genômica Comparativa , Metilação de DNA , Eletroencefalografia/métodos , Feminino , Seguimentos , Humanos , Lactente , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Masculino , Fenótipo , Estudos Retrospectivos , Convulsões/genética , Convulsões/terapia , Adulto Jovem , Receptor Nicotínico de Acetilcolina alfa7/genética , Proteínas Centrais de snRNP/genética
8.
J Med Genet ; 53(4): 256-63, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26747863

RESUMO

BACKGROUND: Wolf-Hirschhorn syndrome (WHS) is a contiguous gene deletion syndrome involving variable size deletions of the 4p16.3 region. Seizures are frequently, but not always, associated with WHS. We hypothesised that the size and location of the deleted region may correlate with seizure presentation. METHODS: Using chromosomal microarray analysis, we finely mapped the breakpoints of copy number variants (CNVs) in 48 individuals with WHS. Seizure phenotype data were collected through parent-reported answers to a comprehensive questionnaire and supplemented with available medical records. RESULTS: We observed a significant correlation between the presence of an interstitial 4p deletion and lack of a seizure phenotype (Fisher's exact test p=3.59e-6). In our cohort, there were five individuals with interstitial deletions with a distal breakpoint at least 751 kbp proximal to the 4p terminus. Four of these individuals have never had an observable seizure, and the fifth individual had a single febrile seizure at the age of 1.5 years. All other individuals in our cohort whose deletions encompass the terminal 751 kbp region report having seizures typical of WHS. Additional examples from the literature corroborate these observations and further refine the candidate seizure susceptibility region to a region 197 kbp in size, starting 368 kbp from the terminus of chromosome 4. CONCLUSIONS: We identify a small terminal region of chromosome 4p that represents a seizure susceptibility region. Deletion of this region in the context of WHS is sufficient for seizure occurrence.


Assuntos
Cromossomos Humanos Par 4/genética , Epilepsia/genética , Convulsões/genética , Síndrome de Wolf-Hirschhorn/genética , Adolescente , Adulto , Criança , Pré-Escolar , Deleção Cromossômica , Variações do Número de Cópias de DNA/genética , Epilepsia/patologia , Feminino , Humanos , Hibridização in Situ Fluorescente , Lactente , Masculino , Análise em Microsséries , Convulsões/patologia , Síndrome de Wolf-Hirschhorn/patologia
9.
J Med Genet ; 53(3): 152-62, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26543203

RESUMO

BACKGROUND: SOX11 is a transcription factor proposed to play a role in brain development. The relevance of SOX11 to human developmental disorders was suggested by a recent report of SOX11 mutations in two patients with Coffin-Siris syndrome. Here we further investigate the role of SOX11 variants in neurodevelopmental disorders. METHODS: We used array based comparative genomic hybridisation and trio exome sequencing to identify children with intellectual disability who have deletions or de novo point mutations disrupting SOX11. The pathogenicity of the SOX11 mutations was assessed using an in vitro gene expression reporter system. Loss-of-function experiments were performed in xenopus by knockdown of Sox11 expression. RESULTS: We identified seven individuals with chromosome 2p25 deletions involving SOX11. Trio exome sequencing identified three de novo SOX11 variants, two missense (p.K50N; p.P120H) and one nonsense (p.C29*). The biological consequences of the missense mutations were assessed using an in vitro gene expression system. These individuals had microcephaly, developmental delay and shared dysmorphic features compatible with mild Coffin-Siris syndrome. To further investigate the function of SOX11, we knocked down the orthologous gene in xenopus. Morphants had significant reduction in head size compared with controls. This suggests that SOX11 loss of function can be associated with microcephaly. CONCLUSIONS: We thus propose that SOX11 deletion or mutation can present with a Coffin-Siris phenotype.


Assuntos
Anormalidades Múltiplas/genética , Face/anormalidades , Deformidades Congênitas da Mão/genética , Deficiência Intelectual/genética , Micrognatismo/genética , Pescoço/anormalidades , Transtornos do Neurodesenvolvimento/genética , Fatores de Transcrição SOXC/genética , Deleção de Sequência , Anormalidades Múltiplas/fisiopatologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Face/fisiopatologia , Feminino , Técnicas de Silenciamento de Genes , Deformidades Congênitas da Mão/fisiopatologia , Humanos , Deficiência Intelectual/fisiopatologia , Masculino , Microcefalia , Micrognatismo/fisiopatologia , Pescoço/fisiopatologia , Transtornos do Neurodesenvolvimento/fisiopatologia , Xenopus
10.
Am J Med Genet C Semin Med Genet ; 169(3): 216-23, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26239400

RESUMO

Since 4p- was first described in 1961, significant progress has been made in our understanding of this classic deletion disorder. We have been able to establish a more complete picture of the WHS phenotype associated with distal 4p monosomy, and we are working to delineate the phenotypic effects when each gene on distal 4p is hemizygous. Our aim is to provide genotype-specific anticipatory guidance and recommendations to families of individuals with a diagnosis of WHS. In addition, establishing the molecular underpinnings of the disorder will potentially suggest targets for molecular treatments. Thus, the next step is to determine the precise effects of specific gene deletions. As we look forward to deepening our understanding of distal 4p deletion, our focus will continue to be on the establishment of robust genotype-phenotype correlations and the penetrance of these phenotypes. We will continue to follow our WHS cohort closely as they age to determine the presence or absence of some of these comorbidities, including hepatic neoplasms, hematopoietic dysfunction, and recurrence of seizures. We will also continue to refine the critical regions for other phenotypes as we enroll additional (hopefully informative) participants into the research study and as the mechanisms of the genes in these regions are elucidated. New animal models will also be developed to further our understanding of the effects of hemizygosity as well as to serve as models for treatment development.


Assuntos
Síndrome de Wolf-Hirschhorn/diagnóstico , Síndrome de Wolf-Hirschhorn/terapia , Genótipo , Humanos , Fenótipo , Síndrome de Wolf-Hirschhorn/etiologia
11.
World J Biol Psychiatry ; 16(6): 376-386, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25903372

RESUMO

OBJECTIVES: MicroRNAs (miRNAs) are post-transcriptional regulators that have been shown to be involved in disease susceptibility. Here we explore the possible contribution of common and rare variants in miRNA genes in autism spectrum disorders (ASD). METHODS: A total of 350 tag SNPs from 163 miRNA genes were genotyped in 636 ASD cases and 673 controls. A replication study was performed in a sample of 449 ASD cases and 415 controls. Additionally, rare variants in 701 miRNA genes of 41 ASD patients were examined using whole-exome sequencing. RESULTS: The most significant association in the discovery sample was obtained for the miR-133b/miR-206 cluster (rs16882131, P = 0.00037). The replication study did not reach significance. However, the pooled analysis (1,085 cases and 1,088 controls) showed association with two miRNA clusters: miR-133b/miR-206 (rs16882131, permP = 0.037) and miR-17/miR-18a/miR-19a/miR-20a/miR-19b-1/miR92a-1 (rs6492538, permP = 0.019). Both miR-133b and miR-206 regulate the MET gene, previously associated with ASD. Rare variant analysis identified mutations in several miRNA genes, among them miR-541, a brain-specific miRNA that regulates SYN1, found mutated in ASD. CONCLUSIONS: Although our results do not establish a clear role for miRNAs in ASD, we pinpointed a few candidate genes. Further exome and GWAS studies are warranted to get more insight into their potential contribution to the disorder.

12.
Eur J Hum Genet ; 23(12): 1694-701, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25782667

RESUMO

Recent findings revealed rare copy number variants and missense changes in the X-linked gene PTCHD1 in autism spectrum disorder (ASD) and intellectual disability (ID). Here, we aim to explore the contribution of common PTCHD1 variants in ASD and gain additional evidence for the role of rare variants of this gene in ASD and ID. A two-stage case-control association study investigated 28 tag single nucleotide polymorphisms (SNPs) in 994 ASD cases and 1035 controls from four European populations. Mutation screening was performed in 673 individuals who included 240 ASD cases, 183 ID patients and 250 controls. The case-control association study showed a significant association with rs7052177 (P=6.13E-4) in the ASD discovery sample that was replicated in an independent sample (P=0.03). A Mantel-Haenszel meta-analysis for rs7052177T considering the four European populations showed an odds ratio of 0.58 (P=7E-05). This SNP is predicted to be located in a transcription factor binding site. No rare missense PTCHD1 variants were found in our ASD cohort and only one was identified in the ID sample. A duplication (27 bp) in the promoter region, absent from 590 controls, was found in three ASD patients (Fisher exact test, P=0.024). A gene reporter assay showed a significant decrease in the transcriptional activity (26%) driven by this variant. Moreover, we found that the longest allele of a trinucleotide repeat located upstream from PTCHD1 was associated with ASD (P=0.003, permP=0.0186). Our results further support the involvement of PTCHD1 in ASD, suggesting that both common and rare variants contribute to the disorder.


Assuntos
Transtorno do Espectro Autista/genética , Deficiência Intelectual/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único , Estudos de Casos e Controles , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Proteínas de Membrana/metabolismo , Mutação de Sentido Incorreto , Regiões Promotoras Genéticas , Repetições de Trinucleotídeos
13.
Am J Med Genet A ; 167A(4): 715-23, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25655306

RESUMO

Chromosome 15q13.3 recurrent microdeletions are causally associated with a wide range of phenotypes, including autism spectrum disorder (ASD), seizures, intellectual disability, and other psychiatric conditions. Whether the reciprocal microduplication is pathogenic is less certain. CHRNA7, encoding for the alpha7 subunit of the neuronal nicotinic acetylcholine receptor, is considered the likely culprit gene in mediating neurological phenotypes in 15q13.3 deletion cases. To assess if CHRNA7 rare variants confer risk to ASD, we performed copy number variant analysis and Sanger sequencing of the CHRNA7 coding sequence in a sample of 135 ASD cases. Sequence variation in this gene remains largely unexplored, given the existence of a fusion gene, CHRFAM7A, which includes a nearly identical partial duplication of CHRNA7. Hence, attempts to sequence coding exons must distinguish between CHRNA7 and CHRFAM7A, making next-generation sequencing approaches unreliable for this purpose. A CHRNA7 microduplication was detected in a patient with autism and moderate cognitive impairment; while no rare damaging variants were identified in the coding region, we detected rare variants in the promoter region, previously described to functionally reduce transcription. This study represents the first sequence variant analysis of CHRNA7 in a sample of idiopathic autism.


Assuntos
Transtorno do Espectro Autista/genética , Receptor Nicotínico de Acetilcolina alfa7/genética , Adolescente , Estudos de Casos e Controles , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Masculino , Polimorfismo de Nucleotídeo Único
14.
Eur J Hum Genet ; 23(6): 761-5, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25271087

RESUMO

Small RNAs (miRNA, siRNA, and piRNA) regulate gene expression through targeted destruction or translational repression of specific messenger RNA in a fundamental biological process called RNA interference (RNAi). The Argonaute proteins, which derive from a highly conserved family of genes found in almost all eukaryotes, are critical mediators of this process. Four AGO genes are present in humans, three of which (AGO 1, 3, and 4) reside in a cluster on chromosome 1p35p34. The effects of germline AGO variants or dosage alterations in humans are not known, however, prior studies have implicated dysregulation of the RNAi mechanism in the pathogenesis of several neurodevelopmental disorders. We describe five patients with hypotonia, poor feeding, and developmental delay who were found to have microdeletions of chromosomal region 1p34.3 encompassing the AGO1 and AGO3 genes. We postulate that haploinsufficiency of AGO1 and AGO3 leading to impaired RNAi may be responsible for the neurocognitive deficits present in these patients. However, additional studies with rigorous phenotypic characterization of larger cohorts of affected individuals and systematic investigation of the underlying molecular defects will be necessary to confirm this.


Assuntos
Proteínas Argonauta/genética , Deleção Cromossômica , Cromossomos Humanos Par 1/genética , Deficiências do Desenvolvimento/genética , Fatores de Iniciação em Eucariotos/genética , Hipotonia Muscular/genética , Adolescente , Criança , Pré-Escolar , Deficiências do Desenvolvimento/diagnóstico , Feminino , Haploinsuficiência , Humanos , Masculino , Hipotonia Muscular/diagnóstico , Síndrome
15.
Am J Hum Genet ; 95(5): 622-32, 2014 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-25439729

RESUMO

Filippi syndrome is a rare, presumably autosomal-recessive disorder characterized by microcephaly, pre- and postnatal growth failure, syndactyly, and distinctive facial features, including a broad nasal bridge and underdeveloped alae nasi. Some affected individuals have intellectual disability, seizures, undescended testicles in males, and teeth and hair abnormalities. We performed homozygosity mapping and whole-exome sequencing in a Sardinian family with two affected children and identified a homozygous frameshift mutation, c.571dupA (p.Ile191Asnfs(∗)6), in CKAP2L, encoding the protein cytoskeleton-associated protein 2-like (CKAP2L). The function of this protein was unknown until it was rediscovered in mice as Radmis (radial fiber and mitotic spindle) and shown to play a pivotal role in cell division of neural progenitors. Sanger sequencing of CKAP2L in a further eight unrelated individuals with clinical features consistent with Filippi syndrome revealed biallelic mutations in four subjects. In contrast to wild-type lymphoblastoid cell lines (LCLs), dividing LCLs established from the individuals homozygous for the c.571dupA mutation did not show CKAP2L at the spindle poles. Furthermore, in cells from the affected individuals, we observed an increase in the number of disorganized spindle microtubules owing to multipolar configurations and defects in chromosome segregation. The observed cellular phenotypes are in keeping with data from in vitro and in vivo knockdown studies performed in human cells and mice, respectively. Our findings show that loss-of-function mutations in CKAP2L are a major cause of Filippi syndrome.


Assuntos
Proteínas do Citoesqueleto/genética , Transtornos do Crescimento/genética , Deficiência Intelectual/genética , Microcefalia/genética , Sindactilia/genética , Animais , Sequência de Bases , Análise Citogenética , Facies , Mutação da Fase de Leitura/genética , Componentes do Gene , Genes Recessivos/genética , Transtornos do Crescimento/patologia , Humanos , Deficiência Intelectual/patologia , Itália , Masculino , Camundongos , Microcefalia/patologia , Microscopia Confocal , Dados de Sequência Molecular , Análise de Sequência de DNA , Sindactilia/patologia
16.
J Neurodev Disord ; 6(1): 17, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25050139

RESUMO

BACKGROUND: Autism spectrum disorder (ASD) is a highly heritable, neurodevelopmental condition showing extreme genetic heterogeneity. While it is well established that rare genetic variation, both de novo and inherited, plays an important role in ASD risk, recent studies also support a rare recessive contribution. METHODS: We identified a compound heterozygous deletion intersecting the CTNNA3 gene, encoding αT-catenin, in a proband with ASD and moderate intellectual disability. The deletion breakpoints were mapped at base-pair resolution, and segregation analysis was performed. We compared the frequency of CTNNA3 exonic deletions in 2,147 ASD cases from the Autism Genome Project (AGP) study versus the frequency in 6,639 controls. Western blot analysis was performed to get a quantitative characterisation of Ctnna3 expression during early brain development in mouse. RESULTS: The CTNNA3 compound heterozygous deletion includes a coding exon, leading to a putative frameshift and premature stop codon. Segregation analysis in the family showed that the unaffected sister is heterozygote for the deletion, having only inherited the paternal deletion. While the frequency of CTNNA3 exonic deletions is not significantly different between ASD cases and controls, no homozygous or compound heterozygous exonic deletions were found in a sample of over 6,000 controls. Expression analysis of Ctnna3 in the mouse cortex and hippocampus (P0-P90) provided support for its role in the early stage of brain development. CONCLUSION: The finding of a rare compound heterozygous CTNNA3 exonic deletion segregating with ASD, the absence of CTNNA3 homozygous exonic deletions in controls and the high expression of Ctnna3 in both brain areas analysed implicate CTNNA3 in ASD susceptibility.

17.
Am J Med Genet A ; 164A(8): 2097-103, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24800990

RESUMO

Comparative genomic hybridization (CGH) arrays have significantly changed the approach to identifying genetic alterations causing intellectual disability and congenital anomalies. Several studies have described the microduplication of Xp22.31, involving the STS gene. In such reports characteristic features and pathogenicity of Xp22.31 duplications remains a subject of debate. Here we present a series of nine previously unreported individuals with Xp22.31 duplications, found through microarray analysis in the course of genetic workup for developmental delay, associated with a combination of talipes anomalies, seizures and/or feeding difficulties. The size of the Xp22.31 duplications ranged from 294 kb to 1.6 Mb. We show a comparison of the breakpoints, inheritance and clinical phenotype, and a review of the literature. This clinically detailed series of Xp22.31 duplication patients provides evidence that the Xp22.31 duplication contributes to a common phenotype.


Assuntos
Duplicação Cromossômica , Cromossomos Humanos X , Pé Torto Equinovaro/genética , Transtornos Cognitivos/genética , Convulsões/genética , Adolescente , Adulto , Criança , Pré-Escolar , Pontos de Quebra do Cromossomo , Hibridização Genômica Comparativa , Facies , Feminino , Ordem dos Genes , Estudos de Associação Genética , Loci Gênicos , Humanos , Lactente , Recém-Nascido , Masculino , Fenótipo , Adulto Jovem
18.
EMBO Mol Med ; 6(6): 795-809, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24737869

RESUMO

Intellectual disability (ID) and autism spectrum disorders (ASDs) are complex neuropsychiatric conditions, with overlapping clinical boundaries in many patients. We identified a novel intragenic deletion of maternal origin in two siblings with mild ID and epilepsy in the CADPS2 gene, encoding for a synaptic protein involved in neurotrophin release and interaction with dopamine receptor type 2 (D2DR). Mutation screening of 223 additional patients (187 with ASD and 36 with ID) identified a missense change of maternal origin disrupting CADPS2/D2DR interaction. CADPS2 allelic expression was tested in blood and different adult human brain regions, revealing that the gene was monoallelically expressed in blood and amygdala, and the expressed allele was the one of maternal origin. Cadps2 gene expression performed in mice at different developmental stages was biallelic in the postnatal and adult stages; however, a monoallelic (maternal) expression was detected in the embryonal stage, suggesting that CADPS2 is subjected to tissue- and temporal-specific regulation in human and mice. We suggest that CADPS2 variants may contribute to ID/ASD development, possibly through a parent-of-origin effect.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Transtornos Globais do Desenvolvimento Infantil/genética , Deficiência Intelectual/genética , Receptores de Dopamina D2/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo , Adulto , Idoso , Alelos , Animais , Transtornos Globais do Desenvolvimento Infantil/metabolismo , Pré-Escolar , Ilhas de CpG , Metilação de DNA , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Variação Genética , Humanos , Lactente , Deficiência Intelectual/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Proteínas do Tecido Nervoso/genética , Linhagem , Mapas de Interação de Proteínas , Deleção de Sequência , Adulto Jovem
19.
Nat Genet ; 45(9): 984-94, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23933821

RESUMO

Most psychiatric disorders are moderately to highly heritable. The degree to which genetic variation is unique to individual disorders or shared across disorders is unclear. To examine shared genetic etiology, we use genome-wide genotype data from the Psychiatric Genomics Consortium (PGC) for cases and controls in schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD). We apply univariate and bivariate methods for the estimation of genetic variation within and covariation between disorders. SNPs explained 17-29% of the variance in liability. The genetic correlation calculated using common SNPs was high between schizophrenia and bipolar disorder (0.68 ± 0.04 s.e.), moderate between schizophrenia and major depressive disorder (0.43 ± 0.06 s.e.), bipolar disorder and major depressive disorder (0.47 ± 0.06 s.e.), and ADHD and major depressive disorder (0.32 ± 0.07 s.e.), low between schizophrenia and ASD (0.16 ± 0.06 s.e.) and non-significant for other pairs of disorders as well as between psychiatric disorders and the negative control of Crohn's disease. This empirical evidence of shared genetic etiology for psychiatric disorders can inform nosology and encourages the investigation of common pathophysiologies for related disorders.


Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Transtornos Mentais/genética , Polimorfismo de Nucleotídeo Único , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/genética , Transtorno Bipolar/genética , Criança , Transtornos Globais do Desenvolvimento Infantil/genética , Doença de Crohn/genética , Transtorno Depressivo Maior/genética , Heterogeneidade Genética , Genoma Humano , Humanos , Padrões de Herança , Esquizofrenia/genética
20.
Am J Med Genet A ; 161A(8): 2084-7, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23825019

RESUMO

Defects in the TUSC3 gene have been identified in individuals with nonsyndromic autosomal recessive intellectual disability (ARID), due to either point mutations or intragenic deletions. We report on a boy with a homozygous microdeletion 8p22, sizing 203 kb, encompassing the first exon of the TUSC3 gene, detected by SNP-array analysis (Human Gene Chip 6.0; Affymetrix). Both nonconsanguineous parents come from a small Sicilian village and were heterozygous carriers of the microdeletion. The propositus had a few dysmorphic features and a moderate cognitive impairment. Verbal communication was impaired, with an inappropriate phonetic inventory, important phono-articolatory distortions, and bucco-phonatory dyspraxia. Comprehension was possible for simple sentences. Behavior was characterized by motor instability, high tendency to irritability and distraibility, anxiety traits, and an oppositional-defiant disorder. His parents were of normal intelligence. TUSC3 is thought to encode a subunit of the endoplasmic reticulum-bound oligosaccharyltranferase complex that catalyzes a pivotal step in the protein N-glycosylation process. TUSC3 has been recently reported as a member of the plasma membrane Mg(2+) transport system, with a possible involvement in learning abilities, working memory and short- and long-term memory. This is the third family in which a deletion has been described. Although the pathogenic mechanism has not been clarified yet, our report argues for a more prominent role of TUSC3 in the etiology of intellectual disability and that deletions encompassing this gene could be more common than expected.


Assuntos
Cromossomos Humanos Par 8/genética , Deficiência Intelectual/genética , Proteínas de Membrana/genética , Deleção de Sequência , Proteínas Supressoras de Tumor/genética , Criança , Hibridização Genômica Comparativa , Genes Recessivos , Homozigoto , Humanos , Hibridização in Situ Fluorescente , Deficiência Intelectual/diagnóstico , Masculino , Fenótipo , Síndrome
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