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1.
Nat Commun ; 10(1): 2837, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253775

RESUMO

The diagnostic yield of exome and genome sequencing remains low (8-70%), due to incomplete knowledge on the genes that cause disease. To improve this, we use RNA-seq data from 31,499 samples to predict which genes cause specific disease phenotypes, and develop GeneNetwork Assisted Diagnostic Optimization (GADO). We show that this unbiased method, which does not rely upon specific knowledge on individual genes, is effective in both identifying previously unknown disease gene associations, and flagging genes that have previously been incorrectly implicated in disease. GADO can be run on www.genenetwork.nl by supplying HPO-terms and a list of genes that contain candidate variants. Finally, applying GADO to a cohort of 61 patients for whom exome-sequencing analysis had not resulted in a genetic diagnosis, yields likely causative genes for ten cases.


Assuntos
Regulação da Expressão Gênica/fisiologia , Predisposição Genética para Doença , Análise de Sequência de RNA/métodos , Transcriptoma , Bases de Dados de Ácidos Nucleicos , Humanos , Modelos Genéticos , Análise de Componente Principal , Software , Interface Usuário-Computador
2.
Am J Med Genet A ; 179(8): 1459-1465, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31134750

RESUMO

BACKGROUND: Growth retardation is one of the main hallmarks of CHARGE syndrome (CS), yet little is known about the body proportions of these children. Knowledge of body proportions in CS may contribute to a better characterization of this syndrome. This knowledge is important when considering starting growth-stimulating therapy. METHODS: For this cross-sectional study, we selected 32 children with CS and a CHD7 mutation at the Dutch CHARGE Family Day in 2016 or 2017 and the International CHARGE conference in Orlando, Florida, in 2017. We used photogrammetric anthropometry-a measurement method based on digital photographs-to determine various body proportions. We compared these to measurements in 21 normally proportioned children with growth hormone deficiency, using independent-samples t test, Mann-Whitney U test, or chi-square test as appropriate. RESULTS: Children with CS appear to have a shorter trunk in proportion to their height, head length, and arm length. Children with CS also had smaller feet proportional to tibia length compared to controls. The change of body proportions with age was similar in children with CS and controls. CONCLUSION: Body proportions in children with CS are significantly different from those of normally proportioned controls, but a similar change of body proportions with age was noted for both groups.

3.
Brain ; 142(1): 80-92, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30544257

RESUMO

Alterations of the N-methyl-d-aspartate receptor (NMDAR) subunit GluN2A, encoded by GRIN2A, have been associated with a spectrum of neurodevelopmental disorders with prominent speech-related features, and epilepsy. We performed a comprehensive assessment of phenotypes with a standardized questionnaire in 92 previously unreported individuals with GRIN2A-related disorders. Applying the criteria of the American College of Medical Genetics and Genomics to all published variants yielded 156 additional cases with pathogenic or likely pathogenic variants in GRIN2A, resulting in a total of 248 individuals. The phenotypic spectrum ranged from normal or near-normal development with mild epilepsy and speech delay/apraxia to severe developmental and epileptic encephalopathy, often within the epilepsy-aphasia spectrum. We found that pathogenic missense variants in transmembrane and linker domains (misTMD+Linker) were associated with severe developmental phenotypes, whereas missense variants within amino terminal or ligand-binding domains (misATD+LBD) and null variants led to less severe developmental phenotypes, which we confirmed in a discovery (P = 10-6) as well as validation cohort (P = 0.0003). Other phenotypes such as MRI abnormalities and epilepsy types were also significantly different between the two groups. Notably, this was paralleled by electrophysiology data, where misTMD+Linker predominantly led to NMDAR gain-of-function, while misATD+LBD exclusively caused NMDAR loss-of-function. With respect to null variants, we show that Grin2a+/- cortical rat neurons also had reduced NMDAR function and there was no evidence of previously postulated compensatory overexpression of GluN2B. We demonstrate that null variants and misATD+LBD of GRIN2A do not only share the same clinical spectrum (i.e. milder phenotypes), but also result in similar electrophysiological consequences (loss-of-function) opposing those of misTMD+Linker (severe phenotypes; predominantly gain-of-function). This new pathomechanistic model may ultimately help in predicting phenotype severity as well as eligibility for potential precision medicine approaches in GRIN2A-related disorders.


Assuntos
Epilepsia/genética , Transtornos do Neurodesenvolvimento/genética , Receptores de N-Metil-D-Aspartato/genética , Adolescente , Adulto , Idoso , Animais , Células Cultivadas , Córtex Cerebelar/metabolismo , Criança , Pré-Escolar , Epilepsia/fisiopatologia , Feminino , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Mutação , Transtornos do Neurodesenvolvimento/fisiopatologia , Fenótipo , Ratos , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores de N-Metil-D-Aspartato/fisiologia , Adulto Jovem
4.
Neurology ; 92(2): e96-e107, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30541864

RESUMO

OBJECTIVE: To delineate the epileptology, a key part of the SYNGAP1 phenotypic spectrum, in a large patient cohort. METHODS: Patients were recruited via investigators' practices or social media. We included patients with (likely) pathogenic SYNGAP1 variants or chromosome 6p21.32 microdeletions incorporating SYNGAP1. We analyzed patients' phenotypes using a standardized epilepsy questionnaire, medical records, EEG, MRI, and seizure videos. RESULTS: We included 57 patients (53% male, median age 8 years) with SYNGAP1 mutations (n = 53) or microdeletions (n = 4). Of the 57 patients, 56 had epilepsy: generalized in 55, with focal seizures in 7 and infantile spasms in 1. Median seizure onset age was 2 years. A novel type of drop attack was identified comprising eyelid myoclonia evolving to a myoclonic-atonic (n = 5) or atonic (n = 8) seizure. Seizure types included eyelid myoclonia with absences (65%), myoclonic seizures (34%), atypical (20%) and typical (18%) absences, and atonic seizures (14%), triggered by eating in 25%. Developmental delay preceded seizure onset in 54 of 56 (96%) patients for whom early developmental history was available. Developmental plateauing or regression occurred with seizures in 56 in the context of a developmental and epileptic encephalopathy (DEE). Fifty-five of 57 patients had intellectual disability, which was moderate to severe in 50. Other common features included behavioral problems (73%); high pain threshold (72%); eating problems, including oral aversion (68%); hypotonia (67%); sleeping problems (62%); autism spectrum disorder (54%); and ataxia or gait abnormalities (51%). CONCLUSIONS: SYNGAP1 mutations cause a generalized DEE with a distinctive syndrome combining epilepsy with eyelid myoclonia with absences and myoclonic-atonic seizures, as well as a predilection to seizures triggered by eating.


Assuntos
Deficiências do Desenvolvimento/genética , Mutação/genética , Espasmos Infantis/genética , Proteínas Ativadoras de ras GTPase/genética , Adolescente , Adulto , Anticonvulsivantes/uso terapêutico , Encéfalo/diagnóstico por imagem , Encefalopatias/complicações , Encefalopatias/diagnóstico por imagem , Encefalopatias/genética , Criança , Pré-Escolar , Estudos de Coortes , Deficiências do Desenvolvimento/complicações , Deficiências do Desenvolvimento/diagnóstico por imagem , Eletroencefalografia , Feminino , Estudos de Associação Genética , Humanos , Lactente , Masculino , Espasmos Infantis/complicações , Espasmos Infantis/diagnóstico por imagem , Espasmos Infantis/tratamento farmacológico , Adulto Jovem
5.
Eur J Med Genet ; 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30125676

RESUMO

We studied the presence of benign infantile epilepsy (BIE), paroxysmal kinesigenic dyskinesia (PKD), and PKD with infantile convulsions (PKD/IC) in patients with a 16p11.2 deletion including PRRT2 or with a PRRT2 loss-of-function sequence variant. Index patients were recruited from seven Dutch university hospitals. The presence of BIE, PKD and PKD/IC was retrospectively evaluated using questionnaires and medical records. We included 33 patients with a 16p11.2 deletion: three (9%) had BIE, none had PKD or PKD/IC. Twelve patients had a PRRT2 sequence variant: BIE was present in four (p = 0.069), PKD in six (p < 0.001) and PKD/IC in two (p = 0.067). Most patients with a deletion had undergone genetic testing because of developmental problems (87%), whereas all patients with a sequence variant were tested because of a movement disorder (55%) or epilepsy (45%). BIE, PKD and PKD/IC clearly showed incomplete penetrance in patients with 16p11.2 deletions, but were found in all and 95% of patients with a PRRT2 sequence variant in our study and a large literature cohort, respectively. Deletions and sequence variants have the same underlying loss-of-function disease mechanism. Thus, differences in ascertainment have led to overestimating the frequency of BIE, PKD and PKD/IC in patients with a PRRT2 sequence variant. This has important implications for counseling if genome-wide sequencing shows such variants in patients not presenting the PRRT2-related phenotypes.

6.
Eur J Hum Genet ; 26(10): 1478-1489, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29904178

RESUMO

Proximal 6q (6q11-q15) deletions are extremely rare and little is known about their phenotypic consequences. Since parents and caregivers now use social media to seek information on rare disorders, the Chromosome 6 Project has successfully collaborated with a Facebook group to collect data on individuals worldwide. Here we describe a cohort of 20 newly identified individuals and 25 literature cases with a proximal 6q deletion. Microarray results and phenotype data were reported directly by parents via a multilingual online questionnaire. This led to phenotype descriptions for five subregions of proximal 6q deletions; comparing the subgroups revealed that 6q11q14.1 deletions presented less severe clinical characteristics than 6q14.2q15 deletions. Gastroesophageal reflux, tracheo/laryngo/bronchomalacia, congenital heart defects, cerebral defects, seizures, and vision and respiratory problems were predominant in those with 6q14.2q15 deletions. Problems related to connective tissue (hypermobility, hernias and foot deformities) were predominantly seen in deletions including the COL12A1 gene (6q13). Congenital heart defects could be linked to deletions of MAP3K7 (6q15) or TBX18 (6q14.3). We further discuss the role of ten genes known or assumed to be related to developmental delay and/or autism (BAI3, RIMS1, KCNQ5, HTR1B, PHIP, SYNCRIP, HTR1E, ZNF292, AKIRIN2 and EPHA7). The most influential gene on the neurodevelopmental phenotype seems to be SYNCRIP (6q14.3), while deletions that include more than two of these genes led to more severe developmental delay. We demonstrate that approaching individuals via social media and collecting data directly from parents is a successful strategy, resulting in better information to counsel families.

7.
Hum Mol Genet ; 27(8): 1343-1352, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29432577

RESUMO

CHARGE syndrome is an autosomal dominant malformation disorder caused by heterozygous loss of function mutations in the chromatin remodeler CHD7. Chd7 regulates the expression of Sema3a, which also contributes to the pathogenesis of Kallmann syndrome, a heterogeneous condition with the typical features hypogonadotropic hypogonadism and an impaired sense of smell. Both features are common in CHARGE syndrome suggesting that SEMA3A may provide a genetic link between these syndromes. Indeed, we find evidence that SEMA3A plays a role in the pathogenesis of CHARGE syndrome. First, Chd7 is enriched at the Sema3a promotor in neural crest cells and loss of function of Chd7 inhibits Sema3a expression. Second, using a Xenopus CHARGE model, we show that human SEMA3A rescues Chd7 loss of function. Third, to elucidate if SEMA3A mutations in addition to CHD7 mutations also contribute to the severity of the CHARGE phenotype, we screened 31 CHD7-positive patients and identified one patient with a heterozygous non-synonymous SEMA3A variant, c.2002A>G (p.I668V). By analyzing protein expression and processing, we did not observe any differences of the p.I668V variant compared with wild-type SEMA3A, while a pathogenic SEMA3A variant p.R66W recently described in a patient with Kallmann syndrome did affect protein secretion. Furthermore, the p.I668V variant, but not the pathogenic p.R66W variant, rescues Chd7 loss of function in Xenopus, indicating that the p.I668V variant is likely benign. Thus, SEMA3A is part of an epigenetic loop that plays a role in the pathogenesis of CHARGE syndrome, however, it seems not to act as a common direct modifier.

8.
Am J Med Genet C Semin Med Genet ; 175(4): 450-464, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29168326

RESUMO

"CHARGE syndrome" is a complex syndrome with high and extremely variable comorbidity. As a result, clinicians may struggle to provide accurate and comprehensive care, and this has led to the publication of several clinical surveillance guidelines and recommendations for CHARGE syndrome, based on both single case observations and cohort studies. Here we perform a structured literature review to examine all the existing advice. Our findings provide additional support for the validity of the recently published Trider checklist. We also identified a gap in literature when reviewing all guidelines and recommendations, and we propose a guideline for neuroradiological evaluation of patients with CHARGE syndrome. This is of importance, as patients with CHARGE are at risk for peri-anesthetic complications, making recurrent imaging procedures under anesthesia a particular risk in clinical practice. However, comprehensive cranial imaging is also of tremendous value for timely diagnosis, proper treatment of symptoms and for further research into CHARGE syndrome. We hope the guideline for neuroradiological evaluation will help clinicians provide efficient and comprehensive care for individuals with CHARGE syndrome.


Assuntos
Síndrome CHARGE/diagnóstico , Síndrome CHARGE/terapia , Encéfalo/anormalidades , Síndrome CHARGE/genética , Gerenciamento Clínico , Humanos , Neuroimagem/métodos , Guias de Prática Clínica como Assunto
10.
Epilepsia Open ; 2(2): 244-254, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-29588953

RESUMO

Objective: To evaluate the diagnostic yield of microarray analysis in a hospital-based cohort of children with seizures and to identify novel candidate genes and susceptibility loci for epilepsy. Methods: Of all children who presented with their first seizure in the University Medical Center Groningen (January 2000 through May 2013) (n = 1,368), we included 226 (17%) children who underwent microarray analysis before June 2014. All 226 children had a definite diagnosis of epilepsy. All their copy number variants (CNVs) on chromosomes 1-22 and X that contain protein-coding genes and have a prevalence of <1% in healthy controls were evaluated for their pathogenicity. Results: Children selected for microarray analysis more often had developmental problems (82% vs. 25%, p < 0.001), facial dysmorphisms (49% vs. 8%, p < 0.001), or behavioral problems (41% vs. 13%, p < 0.001) than children who were not selected. We found known clinically relevant CNVs for epilepsy in 24 of the 226 children (11%). Seventeen of these 24 children had been diagnosed with symptomatic focal epilepsy not otherwise specified (71%) and five with West syndrome (21%). Of these 24 children, many had developmental problems (100%), behavioral problems (54%) or facial dysmorphisms (46%). We further identified five novel CNVs comprising four potential candidate genes for epilepsy: MYT1L, UNC5D, SCN4B, and NRXN3. Significance: The 11% yield in our hospital-based cohort underscores the importance of microarray analysis in diagnostic evaluation of children with epilepsy.

11.
Genet Med ; 19(1): 45-52, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27195816

RESUMO

PURPOSE: Truncating mutations in the maternally imprinted, paternally expressed gene MAGEL2, which is located in the Prader-Willi critical region 15q11-13, have recently been reported to cause Schaaf-Yang syndrome, a Prader-Willi-like disease that manifests as developmental delay/intellectual disability, hypotonia, feeding difficulties, and autism spectrum disorder. The causality of the reported variants in the context of the patients' phenotypes was questioned, as MAGEL2 whole-gene deletions seem to cause little or no clinical phenotype. METHODS: Here we report a total of 18 newly identified individuals with Schaaf-Yang syndrome from 14 families, including 1 family with 3 individuals found to be affected with a truncating variant of MAGEL2, 11 individuals who are clinically affected but were not tested molecularly, and a presymptomatic fetal sibling carrying the pathogenic MAGEL2 variant. RESULTS: All cases harbor truncating mutations of MAGEL2, and nucleotides c.1990-1996 arise as a mutational hotspot, with 10 individuals and 1 fetus harboring a c.1996dupC (p.Q666fs) mutation and 2 fetuses harboring a c.1996delC (p.Q666fs) mutation. The phenotypic spectrum of Schaaf-Yang syndrome ranges from fetal akinesia to neurobehavioral disease and contractures of the small finger joints. CONCLUSION: This study provides strong evidence for the pathogenicity of truncating mutations of the paternal allele of MAGEL2, refines the associated clinical phenotypes, and highlights implications for genetic counseling for affected families.Genet Med 19 1, 45-52.


Assuntos
Transtorno do Espectro Autista/genética , Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Síndrome de Prader-Willi/genética , Proteínas/genética , Adolescente , Adulto , Transtorno do Espectro Autista/fisiopatologia , Criança , Pré-Escolar , Cromossomos Humanos Par 15 , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Expressão Gênica , Impressão Genômica , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/fisiopatologia , Masculino , Mutação , Fenótipo , Síndrome de Prader-Willi/fisiopatologia
12.
Eur J Hum Genet ; 24(12): 1696-1701, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27577546

RESUMO

Phelan-McDermid syndrome (PMS) or 22q13.3 deletion syndrome is a rare neurodevelopmental disorder with at least 60 children and 35 adults diagnosed in the Netherlands. Clinical features are moderate to severe intellectual disability and behavioural problems in the autism spectrum. Other researchers had observed a beneficial effect of intranasal insulin on development and behaviour in a pilot study in six children with PMS. To validate this effect, we conducted a randomized, double-blind, placebo-controlled clinical trial using a stepped-wedge design. From March 2013 to June 2015, 25 children aged 1-16 years with a molecularly confirmed 22q13.3 deletion including the SHANK3 gene participated in the clinical trial for a period of 18 months. Starting 6 months before the trial, children were systematically assessed for cognitive, language and motor development and for adaptive, social and emotional behaviour every 6 months. The second, third and fourth assessments were followed by daily nose sprays containing either intranasal insulin or intranasal placebo for a 6-month period. A fifth assessment was done directly after the end of the trial. Intranasal insulin did not cause serious adverse events. It increased the level of developmental functioning by 0.4-1.4 months per 6-month period, but the effect was not statistically significant in this small group. We found a stronger effect of intranasal insulin, being significant for cognition and social skills, for children older than 3 years, who usually show a decrease of developmental growth. However, clinical trials in larger study populations are required to prove the therapeutic effect of intranasal insulin in PMS.


Assuntos
Transtornos Cromossômicos/reabilitação , Insulina/uso terapêutico , Habilidades Sociais , Administração Intranasal , Adolescente , Criança , Desenvolvimento Infantil , Pré-Escolar , Deleção Cromossômica , Transtornos Cromossômicos/tratamento farmacológico , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 22/genética , Método Duplo-Cego , Feminino , Humanos , Lactente , Insulina/administração & dosagem , Insulina/efeitos adversos , Masculino , Proteínas do Tecido Nervoso/genética
13.
Nat Genet ; 48(8): 877-87, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27399968

RESUMO

Numerous genes are associated with neurodevelopmental disorders such as intellectual disability and autism spectrum disorder (ASD), but their dysfunction is often poorly characterized. Here we identified dominant mutations in the gene encoding the transcriptional repressor and MeCP2 interactor switch-insensitive 3 family member A (SIN3A; chromosome 15q24.2) in individuals who, in addition to mild intellectual disability and ASD, share striking features, including facial dysmorphisms, microcephaly and short stature. This phenotype is highly related to that of individuals with atypical 15q24 microdeletions, linking SIN3A to this microdeletion syndrome. Brain magnetic resonance imaging showed subtle abnormalities, including corpus callosum hypoplasia and ventriculomegaly. Intriguingly, in vivo functional knockdown of Sin3a led to reduced cortical neurogenesis, altered neuronal identity and aberrant corticocortical projections in the developing mouse brain. Together, our data establish that haploinsufficiency of SIN3A is associated with mild syndromic intellectual disability and that SIN3A can be considered to be a key transcriptional regulator of cortical brain development.


Assuntos
Córtex Cerebral/patologia , Haploinsuficiência/genética , Deficiência Intelectual/patologia , Proteína 2 de Ligação a Metil-CpG/metabolismo , Mutação/genética , Neurogênese/fisiologia , Proteínas Repressoras/genética , Anormalidades Múltiplas , Adolescente , Adulto , Agenesia do Corpo Caloso/genética , Agenesia do Corpo Caloso/patologia , Animais , Córtex Cerebral/metabolismo , Criança , Pré-Escolar , Deleção Cromossômica , Feminino , Humanos , Deficiência Intelectual/genética , Masculino , Camundongos , Pessoa de Meia-Idade , Fenótipo , Proteínas Repressoras/metabolismo , Síndrome , Adulto Jovem
14.
Am J Med Genet A ; 170(10): 2681-93, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27311832

RESUMO

Mutations in CREBBP cause Rubinstein-Taybi syndrome. By using exome sequencing, and by using Sanger in one patient, CREBBP mutations were detected in 11 patients who did not, or only in a very limited manner, resemble Rubinstein-Taybi syndrome. The combined facial signs typical for Rubinstein-Taybi syndrome were absent, none had broad thumbs, and three had only somewhat broad halluces. All had apparent developmental delay (being the reason for molecular analysis); five had short stature and seven had microcephaly. The facial characteristics were variable; main characteristics were short palpebral fissures, telecanthi, depressed nasal ridge, short nose, anteverted nares, short columella, and long philtrum. Six patients had autistic behavior, and two had self-injurious behavior. Other symptoms were recurrent upper airway infections (n = 5), feeding problems (n = 7) and impaired hearing (n = 7). Major malformations occurred infrequently. All patients had a de novo missense mutation in the last part of exon 30 or beginning of exon 31 of CREBBP, between base pairs 5,128 and 5,614 (codons 1,710 and 1,872). No missense or truncating mutations in this region have been described to be associated with the classical Rubinstein-Taybi syndrome phenotype. No functional studies have (yet) been performed, but we hypothesize that the mutations disturb protein-protein interactions by altering zinc finger function. We conclude that patients with missense mutations in this specific CREBBP region show a phenotype that differs substantially from that in patients with Rubinstein-Taybi syndrome, and may prove to constitute one (or more) separate entities. © 2016 Wiley Periodicals, Inc.


Assuntos
Proteína de Ligação a CREB/genética , Estudos de Associação Genética , Mutação , Fenótipo , Síndrome de Rubinstein-Taybi/diagnóstico , Síndrome de Rubinstein-Taybi/genética , Adolescente , Adulto , Alelos , Sequência de Aminoácidos , Criança , Pré-Escolar , Exoma , Éxons , Facies , Feminino , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto , Adulto Jovem
15.
J Pediatr ; 176: 150-5, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27321065

RESUMO

OBJECTIVE: To evaluate whether central adrenal insufficiency (CAI) is present in CHARGE (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and/or development, Genital hypoplasia, and Ear abnormalities, including deafness) syndrome, a complex malformation disorder that includes central endocrine dysfunction. STUDY DESIGN: Two cross-sectional studies were performed in Dutch (September 2013-February 2015) and Australian (January 2012-January 2014) CHARGE syndrome clinics. Twenty-seven Dutch and 19 Australian patients (aged 16 months-18 years) with genetically confirmed CHARGE syndrome were included. The low-dose adrenocorticotropin (ACTH) test was used to assess CAI in the Dutch cohort. A peak cortisol response less than 18.1 µg/dL (500 nmol/L) was suspected for CAI, and a glucagon stimulation test was performed for confirmation. Australian patients were screened by single measurements of ACTH and cortisol levels. If adrenal dysfunction was suspected, a standard-dose ACTH test was performed. RESULTS: The low-dose ACTH test was performed in 23 patients (median age 8.4 [1.9-16.9] years). Seven patients showed an insufficient maximum cortisol level (10.3-17.6 µg/dL, 285-485 nmol/L), but CAI was confirmed by glucagon stimulation test in only 1 patient (maximum cortisol level 15.0 µg/dL, 415 nmol/L). In the Australian cohort, 15 patients (median age 9.1 [1.3-17.8] years) were screened, and none had CAI. CONCLUSIONS: CAI was not common in our cohorts, and routine testing of adrenal function in children with CHARGE syndrome is not indicated.


Assuntos
Insuficiência Adrenal/etiologia , Síndrome CHARGE/complicações , Adolescente , Insuficiência Adrenal/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino
16.
J Neurodev Disord ; 8: 16, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27118998

RESUMO

BACKGROUND: Phelan-McDermid syndrome (PMS) or 22q13.3 deletion syndrome is characterized by global developmental delay, cognitive deficits, and behaviour in the autism spectrum. Knowledge about developmental and behavioural characteristics of this rare chromosomal disorder is still limited despite a rapid growing number of diagnoses. Our aim was to study a new and relatively large cohort to further characterize the developmental phenotype of children with PMS. METHODS: We performed a descriptive study of children with a 22q13.3 deletion including SHANK3, aged 8 to 178 months, who were systematically (n = 34) and longitudinally (n = 29) assessed with standardized instruments: Bayley Scales of Infant and Toddler Development, third edition; Wechsler Preschool and Primary Scale of Intelligence, third edition; and Vineland Screener for Social and Adaptive Behavior. RESULTS: Maximal developmental functioning ranged from 34 to 52 months depending on the developmental domain. In general, children performed poorest in the domain of language and best on the domain of motor (young children) or cognitive development (older children). At the individual level, 25 % scored better for receptive and 18 % for expressive language, whereas 22 % scored better for fine and 33 % for gross motor function. Developmental quotients were higher in younger children and decreased with age for all developmental domains, with 38 % of the children showing no improvement of cognitive developmental functioning. Almost all children (33/34) had significant deficits in adaptive behaviour. Children with very small deletions, covering only the SHANK3, ACR, and RABL2B genes, had a more favourable developmental phenotype. CONCLUSIONS: Cognitive, motor, and especially language development were significantly impaired in all children with PMS but also highly variable and unpredictable. In addition, deficits in adaptive behaviour further hampered their cognitive development. Therefore, cognitive and behavioural characteristics should be evaluated and followed in each child with PMS to adapt supportive and therapeutic strategies to individual needs. Further research evaluating the relationship between deletion characteristics and the developmental phenotype is warranted to improve counselling of parents.

17.
Am J Med Genet A ; 170A(5): 1148-54, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26850571

RESUMO

CHARGE syndrome is a dominant disorder characterized by ocular colobomata, heart defects, choanal atresia, retardation of growth and development, genital hypoplasia, and ear abnormalities including deafness and vestibular disorders. The majority of individuals with CHARGE have pathogenic variants in the gene encoding CHD7, a chromatin remodeling protein. Here, we present a 15-year-old girl with clinical features of CHARGE syndrome and a de novo 6.5 Mb gain of genomic material at 2p25.3-p25.2. The duplicated region contained 24 genes, including the early and broadly expressed transcription factor gene SOX11. Analysis of 28 other patients with CHARGE showed no SOX11 copy number changes or pathogenic sequence variants. To our knowledge, this child's chromosomal abnormality is unique and represents the first co-occurrence of duplication 2p25 and clinical features of CHARGE syndrome. We compare our patient's phenotype to ten previously published patients with isolated terminal duplication 2p, and elaborate on the clinical diagnosis of CHARGE in the context of atypical genetic findings.


Assuntos
Anormalidades Múltiplas/genética , Síndrome CHARGE/genética , Fatores de Transcrição SOXC/genética , Trissomia/genética , Anormalidades Múltiplas/fisiopatologia , Síndrome CHARGE/fisiopatologia , Criança , Cromossomos Humanos Par 2/genética , Variações do Número de Cópias de DNA/genética , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Feminino , Duplicação Gênica/genética , Testes Genéticos , Humanos , Mutação , Fatores de Transcrição SOXC/biossíntese , Trissomia/fisiopatologia
18.
Am J Hum Genet ; 98(2): 373-81, 2016 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-26833328

RESUMO

Mutations in more than a hundred genes have been reported to cause X-linked recessive intellectual disability (ID) mainly in males. In contrast, the number of identified X-linked genes in which de novo mutations specifically cause ID in females is limited. Here, we report 17 females with de novo loss-of-function mutations in USP9X, encoding a highly conserved deubiquitinating enzyme. The females in our study have a specific phenotype that includes ID/developmental delay (DD), characteristic facial features, short stature, and distinct congenital malformations comprising choanal atresia, anal abnormalities, post-axial polydactyly, heart defects, hypomastia, cleft palate/bifid uvula, progressive scoliosis, and structural brain abnormalities. Four females from our cohort were identified by targeted genetic testing because their phenotype was suggestive for USP9X mutations. In several females, pigment changes along Blaschko lines and body asymmetry were observed, which is probably related to differential (escape from) X-inactivation between tissues. Expression studies on both mRNA and protein level in affected-female-derived fibroblasts showed significant reduction of USP9X level, confirming the loss-of-function effect of the identified mutations. Given that some features of affected females are also reported in known ciliopathy syndromes, we examined the role of USP9X in the primary cilium and found that endogenous USP9X localizes along the length of the ciliary axoneme, indicating that its loss of function could indeed disrupt cilium-regulated processes. Absence of dysregulated ciliary parameters in affected female-derived fibroblasts, however, points toward spatiotemporal specificity of ciliary USP9X (dys-)function.


Assuntos
Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Mutação , Ubiquitina Tiolesterase/genética , Adolescente , Sequência de Bases , Criança , Pré-Escolar , Atresia das Cóanas/diagnóstico , Atresia das Cóanas/genética , Deficiências do Desenvolvimento/diagnóstico , Feminino , Genes Ligados ao Cromossomo X , Testes Genéticos , Humanos , Deficiência Intelectual/diagnóstico , Dados de Sequência Molecular , Fenótipo , Ubiquitina Tiolesterase/metabolismo , Inativação do Cromossomo X , Adulto Jovem
19.
BMC Med Genomics ; 9: 7, 2016 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-26846091

RESUMO

BACKGROUND: Clinical and genetic heterogeneity in monogenetic disorders represents a major diagnostic challenge. Although the presence of particular clinical features may aid in identifying a specific cause in some cases, the majority of patients remain undiagnosed. Here, we investigated the utility of whole-exome sequencing as a diagnostic approach for establishing a molecular diagnosis in a highly heterogeneous group of patients with varied intellectual disability and microcephaly. METHODS: Whole-exome sequencing was performed in 38 patients, including three sib-pairs, in addition to or in parallel with genetic analyses that were performed during the diagnostic work-up of the study participants. RESULTS: In ten out of these 35 families (29 %), we found mutations in genes already known to be related to a disorder in which microcephaly is a main feature. Two unrelated patients had mutations in the ASPM gene. In seven other patients we found mutations in RAB3GAP1, RNASEH2B, KIF11, ERCC8, CASK, DYRK1A and BRCA2. In one of the sib-pairs, mutations were found in the RTTN gene. Mutations were present in seven out of our ten families with an established etiological diagnosis with recessive inheritance. CONCLUSIONS: We demonstrate that whole-exome sequencing is a powerful tool for the diagnostic evaluation of patients with highly heterogeneous neurodevelopmental disorders such as intellectual disability with microcephaly. Our results confirm that autosomal recessive disorders are highly prevalent among patients with microcephaly.


Assuntos
Exoma/genética , Deficiência Intelectual/complicações , Deficiência Intelectual/genética , Microcefalia/complicações , Microcefalia/genética , Análise de Sequência de DNA/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto Jovem
20.
Eur J Paediatr Neurol ; 20(3): 489-92, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26818399

RESUMO

We describe an 18-year-old male patient with myoclonic astatic epilepsy (MAE), moderate to severe intellectual disability, behavioural problems, several dysmorphisms and a 1.2-Mb de novo deletion on chromosome 16p11.2. This deletion results in haploinsufficiency of STX1B and other genes. Recently, variants in the STX1B gene have been associated with a wide spectrum of fever-related epilepsies ranging from single febrile seizures to severe epileptic encephalopathies. Two previously reported patients with a STX1B missense variant or deletion were diagnosed with MAE. Our observation of a STX1B deletion in a third patient with MAE therefore supports that STX1B gene variants or deletions can be involved in the aetiology of MAE. Furthermore, STX1B encodes for syntaxin-1B, of which interaction with the protein encoded by the STXBP1 gene is essential for the regulation of the synaptic transmission of neurotransmitters. STXBP1 gene variants have been identified in patients with many different types of epilepsy, including Dravet syndrome and epileptic encephalopathies, suggesting STX1B plays a similar role. We recommend that analysis of STX1B should be considered in the diagnostic work-up of individuals with MAE.


Assuntos
Epilepsias Mioclônicas/genética , Haploinsuficiência/genética , Sintaxina 1/genética , Adolescente , Epilepsias Mioclônicas/diagnóstico , Humanos , Masculino , Deleção de Sequência/genética
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