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1.
Am J Hum Genet ; 104(2): 203-212, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30612693

RESUMO

Using exome sequencing, we have identified de novo variants in MAPK8IP3 in 13 unrelated individuals presenting with an overlapping phenotype of mild to severe intellectual disability. The de novo variants comprise six missense variants, three of which are recurrent, and three truncating variants. Brain anomalies such as perisylvian polymicrogyria, cerebral or cerebellar atrophy, and hypoplasia of the corpus callosum were consistent among individuals harboring recurrent de novo missense variants. MAPK8IP3 has been shown to be involved in the retrograde axonal-transport machinery, but many of its specific functions are yet to be elucidated. Using the CRISPR-Cas9 system to target six conserved amino acid positions in Caenorhabditis elegans, we found that two of the six investigated human alterations led to a significantly elevated density of axonal lysosomes, and five variants were associated with adverse locomotion. Reverse-engineering normalized the observed adverse effects back to wild-type levels. Combining genetic, phenotypic, and functional findings, as well as the significant enrichment of de novo variants in MAPK8IP3 within our total cohort of 27,232 individuals who underwent exome sequencing, we implicate de novo variants in MAPK8IP3 as a cause of a neurodevelopmental disorder with intellectual disability and variable brain anomalies.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Encéfalo/anormalidades , Encéfalo/metabolismo , Deficiência Intelectual/genética , Mutação , Proteínas do Tecido Nervoso/genética , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adolescente , Animais , Encéfalo/diagnóstico por imagem , Sistemas CRISPR-Cas , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Criança , Pré-Escolar , Simulação por Computador , Feminino , Humanos , Deficiência Intelectual/diagnóstico por imagem , Locomoção , Lisossomos/metabolismo , Masculino , Modelos Moleculares , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/metabolismo , Sequenciamento Completo do Exoma , Adulto Jovem
2.
Am J Med Genet A ; 179(2): 219-223, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30556359

RESUMO

Kabuki syndrome (KS) is a multiple congenital malformation syndrome which has been described across all ethnic groups. Most KS patients possess two genetic subtypes: KMT2D-associated, autosomal-dominant KS type 1 (KS1; OMIM 147920); and KDM6A-associated, X-linked-dominant KS type 2. Generalized joint hypermobility is one feature of KS, but its exact incidence and pattern is not well described in the literature. As part of our prospective study on the metabolic and growth effect of GH treatment, we assessed children from our Dutch Kabuki cohort who were eligible for growth hormone therapy. We assessed severity and pattern of joint hypermobility, both before and after 24 months of growth hormone replacement therapy. The prevalence of hypermobility was 31% in boys and 14% in girls using the Beighton score and 69% in boys and 57% in girls using the Bulbena score. This varies from the general population where girls are more affected. After 2 years of growth hormone treatment, there was a statistically significant decrease in the presence of joint hypermobility to 6% using the Bulbena score and none with respect to the Beighton score. We hypothesized that this result suggests a direct effect of growth hormone on connective tissue in patients with KS.

3.
Ann Neurol ; 84(5): 788-795, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30269351

RESUMO

NBEA is a candidate gene for autism, and de novo variants have been reported in neurodevelopmental disease (NDD) cohorts. However, NBEA has not been rigorously evaluated as a disease gene, and associated phenotypes have not been delineated. We identified 24 de novo NBEA variants in patients with NDD, establishing NBEA as an NDD gene. Most patients had epilepsy with onset in the first few years of life, often characterized by generalized seizure types, including myoclonic and atonic seizures. Our data show a broader phenotypic spectrum than previously described, including a myoclonic-astatic epilepsy-like phenotype in a subset of patients. Ann Neurol 2018;84:796-803.

4.
Nucl Med Commun ; 39(11): 961-968, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30106798

RESUMO

In patients with neurofibromatosis type 1, transformation of neurofibromas into a malignant peripheral nerve sheath tumor (MPNST) is a severe complication of the disease. Fluorine-18-fluorodeoxyglucose PET/computed tomography (PET/CT) is a viable option for detecting malignant tumors in neurofibromatosis type 1 patients. The aim of this review was to assess the diagnostic performance of the most frequently used parameters of PET/CT in detecting MPNST. An extensive computer search was performed using the Cochrane Library, Pubmed, and Medline/Embase databases. Two reviewers independently extracted data of relevant studies and assessed the methodological quality (QUADAS-2). The diagnostic performance of PET/CT parameters in individual studies was determined by calculating a diagnostic odds ratio (DOR) using the absolute numbers of true-positive, true-negative, false-positive, and false-negative test results. A total of eight studies were included, of which three evaluated the standardized uptake value as a diagnostic parameter, two assessed the tumor-to-liver (T/L) ratio, and three articles described both parameters. The cut-off values for maximum standardized uptake value (SUVmax) ranged from 3.2 to 4.5; for the T/L ratio, the cut-off values were between 1.0 and 4.3. The sensitivity and specificity ranged from 90 to 100% and from 80 to 100%, respectively (SUVmax). T/L ratios were associated with 92-100% sensitivity and 72-94% specificity. The corresponding DORs ranged from 57 to 145 (SUVmax) and 35 to 655 (T/L ratio). Both the SUV and the T/L ratio are associated with high sensitivity combined with acceptable specificity in detecting MPNST. There is a tendency toward higher DORs using the T/L ratio, but the number of studies is limited.


Assuntos
Transformação Celular Neoplásica , Fluordesoxiglucose F18 , Neurofibromatose 1/diagnóstico por imagem , Neurofibromatose 1/patologia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Humanos
5.
Ann Neurol ; 84(2): 200-207, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30014507

RESUMO

OBJECTIVE: Developmental delay (DD) with favorable intellectual outcome and mild intellectual disability (ID) are mostly considered to be of complex genetic and environmental origin, but, in fact, often remain unclear. We aimed at proving our assumption that also mild cases of DD and ID may be of monogenic etiology. METHODS: We clinically evaluated 8 individuals and performed exome sequencing or array copy number analysis and identified variants in CUX1 as the likely cause. In addition, we included a case from the public database, DECIPHER. RESULTS: All 9 individuals harbored heterozygous null-allele variants in CUX1, encoding the Cut-homeobox 1 transcription factor that is involved in regulation of dendritogenesis and cortical synapse formation in layer II to IV cortical neurons. Six variants arose de novo, while in one family the variant segregated with ID. Of the 9 included individuals, 2 were diagnosed with moderate ID, 3 with mild ID, and 3 showed a normal age-related intelligence at ages 4, 6, and 8 years after a previous history of significant DD. INTERPRETATION: Our results suggest that null-allele variants, and thus haploinsufficiency of CUX1, cause an isolated phenotype of DD or ID with possible catch-up development. This illustrates that such a developmental course is not necessarily genetic complex, but may also be attributed to a monogenic cause. Ann Neurol 2018;84:200-207.

6.
Am J Hum Genet ; 102(1): 44-57, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29276004

RESUMO

Although the role of typical Rho GTPases and other Rho-linked proteins in synaptic plasticity and cognitive function and dysfunction is widely acknowledged, the role of atypical Rho GTPases (such as RHOBTB2) in neurodevelopment has barely been characterized. We have now identified de novo missense variants clustering in the BTB-domain-encoding region of RHOBTB2 in ten individuals with a similar phenotype, including early-onset epilepsy, severe intellectual disability, postnatal microcephaly, and movement disorders. Three of the variants were recurrent. Upon transfection of HEK293 cells, we found that mutant RHOBTB2 was more abundant than the wild-type, most likely because of impaired degradation in the proteasome. Similarly, elevated amounts of the Drosophila ortholog RhoBTB in vivo were associated with seizure susceptibility and severe locomotor defects. Knockdown of RhoBTB in the Drosophila dendritic arborization neurons resulted in a decreased number of dendrites, thus suggesting a role of RhoBTB in dendritic development. We have established missense variants in the BTB-domain-encoding region of RHOBTB2 as causative for a developmental and epileptic encephalopathy and have elucidated the role of atypical Rho GTPase RhoBTB in Drosophila neurological function and possibly dendrite development.

7.
Clin Case Rep ; 5(8): 1213-1217, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28781826

RESUMO

Clinical geneticists, neurologists, psychiatrists, and other healthcare providers can learn from this case report that patients with a behavioral phenotype that includes a mild learning disability may also require a thorough examination, including brain MRI and whole-exome sequencing.

8.
Horm Res Paediatr ; 88(3-4): 258-264, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28793284

RESUMO

BACKGROUND/AIMS: Kabuki syndrome (KS) is a rare genetic malformation syndrome, resulting in characteristic features such as short stature. We investigate whether growth hormone (GH) treatment increases linear height and influences body proportions in KS children. METHODS: In this prospective study, 18 genetically confirmed prepubertal KS children (9 females and 9 males) aged from 3.8 to 10.1 years (mean 6.8 ± 2.1 years) were treated with recombinant human GH (rhGH) for 1 year. Calculations for height, height velocity, BMI, sitting height, and subischial leg length were made. Bone age, insulin-like growth factor (IGF-I), and IGF binding protein 3 (IGFBP-3) were also measured. RESULTS: This study showed an increase in height standard deviation score (SDS) for the whole group from -2.40 to -1.69 (p < 0.05) after 1 year of rhGH treatment. The change in height SDS within 1 year was >0.7 SDS for 10 subjects and >0.5 SDS for 3 subjects. The mean IGF-I SDS at the start of the study was -0.70 (±1.07), which increased after 12 months to 1.41 (±0.91) (p < 0.05). KS children who received rhGH at a younger age displayed significantly greater increases in height than those who started when they were older. The same was true for both gene mutation KMT2D versus KDM6A and for GH deficiency versus non-GH deficiency KS children (p < 0.05). Throughout the course of rhGH treatment, the subjects' body proportions remained normal. CONCLUSIONS: All participants experienced catch-up growth during the year of rhGH treatment, but without an influence on body proportions.


Assuntos
Anormalidades Múltiplas/tratamento farmacológico , Nanismo Hipofisário/tratamento farmacológico , Face/anormalidades , Doenças Hematológicas/tratamento farmacológico , Terapia de Reposição Hormonal , Hormônio do Crescimento Humano/uso terapêutico , Doenças Vestibulares/tratamento farmacológico , Anormalidades Múltiplas/genética , Criança , Pré-Escolar , Proteínas de Ligação a DNA/genética , Nanismo Hipofisário/genética , Feminino , Doenças Hematológicas/genética , Histona Desmetilases/genética , Humanos , Masculino , Mutação , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Resultado do Tratamento , Doenças Vestibulares/genética
10.
Ophthalmic Genet ; 38(2): 101-107, 2017 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27070436

RESUMO

Anterior segment dysgeneses are developmental anomalies of the anterior eye segment that can occur as isolated defects or as part of various syndromes. A subgroup is caused by abnormal embryonic neural crest development. The Axenfeld-Rieger syndrome is an umbrella term for a continuum of anterior segment dysgeneses of neural crest origin, characterized by the presence of the Axenfeld or Rieger eye malformation predisposing for glaucoma. Additionally, other structures of neural crest origin can be variably affected giving rise to a wide spectrum of associated extra-ocular malformations. Key clinical features comprise facial dysmorphism including mid-face and dental hypoplasia, hearing loss, cardiac anomalies, and involuted periumbilical skin. The Axenfeld-Rieger syndrome is genetically heterogeneous and about 16% of cases are caused by heterozygous mutations in FOXC1 at 6p25.3, a transcription factor gene regulating neural crest cell development. There is considerable clinical overlap between the Axenfeld-Rieger syndrome and the 6p25 deletion syndrome, a microdeletion syndrome characterized by heterozygous loss of FOXC1. In both syndromes, FOXC1 haploinsufficiency seems to be pathogenic. Here, we review the clinical features and pathogenesis of the 6p25 deletion syndrome.


Assuntos
Segmento Anterior do Olho/anormalidades , Deleção Cromossômica , Cromossomos Humanos Par 6/genética , Anormalidades do Olho/diagnóstico , Crista Neural/patologia , Anormalidades do Olho/genética , Oftalmopatias Hereditárias , Feminino , Fatores de Transcrição Forkhead/genética , Humanos , Adulto Jovem
11.
Am J Hum Genet ; 100(1): 91-104, 2017 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-27939640

RESUMO

Identification of over 500 epigenetic regulators in humans raises an interesting question regarding how chromatin dysregulation contributes to different diseases. Bromodomain and PHD finger-containing protein 1 (BRPF1) is a multivalent chromatin regulator possessing three histone-binding domains, one non-specific DNA-binding module, and several motifs for interacting with and activating three lysine acetyltransferases. Genetic analyses of fish brpf1 and mouse Brpf1 have uncovered an important role in skeletal, hematopoietic, and brain development, but it remains unclear how BRPF1 is linked to human development and disease. Here, we describe an intellectual disability disorder in ten individuals with inherited or de novo monoallelic BRPF1 mutations. Symptoms include infantile hypotonia, global developmental delay, intellectual disability, expressive language impairment, and facial dysmorphisms. Central nervous system and spinal abnormalities are also seen in some individuals. These clinical features overlap with but are not identical to those reported for persons with KAT6A or KAT6B mutations, suggesting that BRPF1 targets these two acetyltransferases and additional partners in humans. Functional assays showed that the resulting BRPF1 variants are pathogenic and impair acetylation of histone H3 at lysine 23, an abundant but poorly characterized epigenetic mark. We also found a similar deficiency in different lines of Brpf1-knockout mice. These data indicate that aberrations in the chromatin regulator gene BRPF1 cause histone H3 acetylation deficiency and a previously unrecognized intellectual disability syndrome.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Cromatina/metabolismo , Histonas/metabolismo , Deficiência Intelectual/genética , Mutação , Proteínas Nucleares/genética , Acetilação , Adolescente , Alelos , Animais , Proteínas de Transporte/genética , Criança , Cromatina/química , Deficiências do Desenvolvimento/genética , Face/anormalidades , Feminino , Histona Acetiltransferases/genética , Humanos , Lisina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hipotonia Muscular/genética , Síndrome
12.
Am J Hum Genet ; 99(4): 991-999, 2016 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-27693232

RESUMO

The ASXL genes (ASXL1, ASXL2, and ASXL3) participate in body patterning during embryogenesis and encode proteins involved in epigenetic regulation and assembly of transcription factors to specific genomic loci. Germline de novo truncating variants in ASXL1 and ASXL3 have been respectively implicated in causing Bohring-Opitz and Bainbridge-Ropers syndromes, which result in overlapping features of severe intellectual disability and dysmorphic features. ASXL2 has not yet been associated with a human Mendelian disorder. In this study, we performed whole-exome sequencing in six unrelated probands with developmental delay, macrocephaly, and dysmorphic features. All six had de novo truncating variants in ASXL2. A careful review enabled the recognition of a specific phenotype consisting of macrocephaly, prominent eyes, arched eyebrows, hypertelorism, a glabellar nevus flammeus, neonatal feeding difficulties, hypotonia, and developmental disabilities. Although overlapping features with Bohring-Opitz and Bainbridge-Ropers syndromes exist, features that distinguish the ASXL2-associated condition from ASXL1- and ASXL3-related disorders are macrocephaly, absence of growth retardation, and more variability in the degree of intellectual disabilities. We were also able to demonstrate with mRNA studies that these variants are likely to exert a dominant-negative effect, given that both alleles are expressed in blood and the mutated ASXL2 transcripts escape nonsense-mediated decay. In conclusion, de novo truncating variants in ASXL2 underlie a neurodevelopmental syndrome with a clinically recognizable phenotype. This report expands the germline disorders that are linked to the ASXL genes.


Assuntos
Fenótipo , Proteínas Repressoras/genética , Criança , Pré-Escolar , Deficiências do Desenvolvimento/genética , Exoma/genética , Sobrancelhas/anormalidades , Humanos , Hipertelorismo/genética , Lactente , Recém-Nascido , Masculino , Megalencefalia/genética , Hipotonia Muscular/genética , RNA Mensageiro/metabolismo , Síndrome
13.
Am J Med Genet A ; 170(12): 3069-3082, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27648933

RESUMO

Rubinstein-Taybi syndrome (RSTS) is a developmental disorder characterized by a typical face and distal limbs abnormalities, intellectual disability, and a vast number of other features. Two genes are known to cause RSTS, CREBBP in 60% and EP300 in 8-10% of clinically diagnosed cases. Both paralogs act in chromatin remodeling and encode for transcriptional co-activators interacting with >400 proteins. Up to now 26 individuals with an EP300 mutation have been published. Here, we describe the phenotype and genotype of 42 unpublished RSTS patients carrying EP300 mutations and intragenic deletions and offer an update on another 10 patients. We compare the data to 308 individuals with CREBBP mutations. We demonstrate that EP300 mutations cause a phenotype that typically resembles the classical RSTS phenotype due to CREBBP mutations to a great extent, although most facial signs are less marked with the exception of a low-hanging columella. The limb anomalies are more similar to those in CREBBP mutated individuals except for angulation of thumbs and halluces which is very uncommon in EP300 mutated individuals. The intellectual disability is variable but typically less marked whereas the microcephaly is more common. All types of mutations occur but truncating mutations and small rearrangements are most common (86%). Missense mutations in the HAT domain are associated with a classical RSTS phenotype but otherwise no genotype-phenotype correlation is detected. Pre-eclampsia occurs in 12/52 mothers of EP300 mutated individuals versus in 2/59 mothers of CREBBP mutated individuals, making pregnancy with an EP300 mutated fetus the strongest known predictor for pre-eclampsia. © 2016 Wiley Periodicals, Inc.


Assuntos
Proteína de Ligação a CREB/genética , Proteína p300 Associada a E1A/genética , Pré-Eclâmpsia/genética , Síndrome de Rubinstein-Taybi/genética , Adulto , Montagem e Desmontagem da Cromatina/genética , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Pré-Eclâmpsia/fisiopatologia , Gravidez , Síndrome de Rubinstein-Taybi/patologia , Deleção de Sequência
14.
Horm Res Paediatr ; 86(5): 319-324, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27649541

RESUMO

BACKGROUND/AIMS: Kabuki syndrome is a multiple congenital malformation syndrome with a variety of clinical features including short stature. The cause of this postnatal short stature remains unknown. METHODS: Eighteen children with genetically proven Kabuki syndrome (8 boys and 10 girls; ages 3.3-9.9 years, with a mean of 6.7 years) who underwent growth hormone (GH) stimulation tests were evaluated in a prospective study. Two GH stimulation tests were conducted, including insulin-like growth factor I (IGF-I) and IGF-binding protein 3 (IGFBP-3) serum levels. GH stimulation peaks in relation to age, sex, height, body mass index (BMI), IGF-I, and IGFBP-3 SD scores (SDS) were analyzed. RESULTS: Five of the 18 children (27.8%) were biochemically GH deficient. This was not correlated with BMI SDS. Of all patients, only 1 had an IGF-I below -2 SD and did not fulfill the GH deficiency criteria. The mean IGF-I level was below normal (-0.8 SD). All subjects had normal IGFBP-3 levels. CONCLUSIONS: The utility of performing GH stimulation tests on Kabuki syndrome children as an indication of GH status in short stature is questionable. IGF-I levels did correlate neither with the GH stimulation peak nor consequently with the diagnosis of GH deficiency.


Assuntos
Anormalidades Múltiplas , Índice de Massa Corporal , Face/anormalidades , Doenças Hematológicas , Hormônio do Crescimento Humano/administração & dosagem , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Doenças Vestibulares , Anormalidades Múltiplas/sangue , Anormalidades Múltiplas/patologia , Anormalidades Múltiplas/fisiopatologia , Criança , Pré-Escolar , Face/patologia , Face/fisiopatologia , Feminino , Doenças Hematológicas/sangue , Doenças Hematológicas/patologia , Doenças Hematológicas/fisiopatologia , Humanos , Masculino , Estudos Prospectivos , Doenças Vestibulares/sangue , Doenças Vestibulares/patologia , Doenças Vestibulares/fisiopatologia
15.
Am J Med Genet A ; 170(12): 3172-3179, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27530205

RESUMO

Kabuki syndrome is a multiple congenital malformation syndrome with a spectrum of clinical features including short stature. Since there is no growth data on Kabuki syndrome patients with a proven KMT2D gene mutation, further research on growth and growth patterns is indicated. Data for this growth study on subjects with Kabuki syndrome were collected from referring clinicians. Subjects were eligible for inclusion in the study if the following criteria were met: a genetically confirmed diagnosis of Kabuki syndrome and no current treatment with growth hormones or other drugs that could influence growth. We present a report on growth data (n = 39) in Kabuki syndrome patients. The data showed that postnatal growth retardation is a clinical feature in all cases. All Kabuki syndrome subjects showed a growth deflection during childhood and a diminution of the pubertal growth spurt. A genotype-phenotype correlation was not observed. Further research is required in order to determine whether a defect in the growth hormone/IGF-I axis and estrogen receptor plays a role in the growth retardation. © 2016 Wiley Periodicals, Inc.


Assuntos
Anormalidades Múltiplas/genética , Proteínas de Ligação a DNA/genética , Deficiências do Desenvolvimento/genética , Face/anormalidades , Doenças Hematológicas/genética , Deficiência Intelectual/genética , Proteínas de Neoplasias/genética , Doenças Vestibulares/genética , Anormalidades Múltiplas/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Deficiências do Desenvolvimento/fisiopatologia , Face/fisiopatologia , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Doenças Hematológicas/fisiopatologia , Humanos , Fator de Crescimento Insulin-Like I , Deficiência Intelectual/fisiopatologia , Masculino , Pessoa de Meia-Idade , Mutação , Doenças Vestibulares/fisiopatologia , Adulto Jovem
16.
Br J Nutr ; 116(4): 576-92, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27323230

RESUMO

Primary cilia are organelles that are present on many different cell types, either transiently or permanently. They play a crucial role in receiving signals from the environment and passing these signals to other parts of the cell. In that way, they are involved in diverse processes such as adipocyte differentiation and olfactory sensation. Mutations in genes coding for ciliary proteins often have pleiotropic effects and lead to clinical conditions, ciliopathies, with multiple symptoms. In this study, we reviewed observations from ciliopathies with obesity as one of the symptoms. It shows that variation in cilia-related genes is itself not a major cause of obesity in the population but may be a part of the multifactorial aetiology of this complex condition. Both common polymorphisms and rare deleterious variants may contribute to the obesity risk. Genotype-phenotype relationships have been noticed. Among the ciliary genes, obesity differs with regard to severity and age of onset, which may relate to the influence of each gene on the balance between pro- and anti-adipogenic processes. Analysis of the function and location of the proteins encoded by these ciliary genes suggests that obesity is more linked to activities at the basal area of the cilium, including initiation of the intraflagellar transport, but less to the intraflagellar transport itself. Regarding the role of cilia, three possible mechanistic processes underlying obesity are described: adipogenesis, neuronal food intake regulation and food odour perception.


Assuntos
Cílios/fisiologia , Obesidade/etiologia , Adipogenia/fisiologia , Transporte Biológico , Diferenciação Celular , Cílios/genética , Variação Genética , Humanos , Mutação , Obesidade/fisiopatologia , Fatores de Risco
17.
Int J Pediatr Otorhinolaryngol ; 83: 74-7, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26968057

RESUMO

Anterior neck masses in young children can be a diagnostic challenge for otolaryngologists and radiologists. We present a rare case of herniation of normal mediastinal thymus in a four-year-old girl. Additional medical features as an inguinal hernia and trochlear nerve paresis raised the question whether there is a causal relationship or an association. A connective tissue disorder could not be diagnosed as possible causal factor to the abnormal movement of the mediastinal thymus. Awareness and recognition of this benign phenomenon is important in order to avoid unnecessary biopsy or surgery. Diagnosis can be confirmed by ultrasonography. Magnetic Resonance Imaging might be valuable in order to obtain more information about the extension of the mass.


Assuntos
Hérnia/diagnóstico , Doenças do Mediastino/diagnóstico , Timo/patologia , Biópsia , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Imagem por Ressonância Magnética , Pescoço
18.
Fetal Pediatr Pathol ; 35(2): 112-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26882358

RESUMO

Congenital nephrotic syndrome (CNS) caused by a mutation in the Wilms tumor 1 suppressor gene (WT1) is part of Denys Drash Syndrome or Frasier syndrome. In the framework of genetic counseling, the diagnosis of CNS can be refined with gene mutation studies on long-term stored formalin-fixed paraffin-embedded tissue from postmortem examination. We report a case of diffuse mesangial sclerosis with perinatal death caused by a de novo mutation in the WT1 gene in a girl with an XY-genotype. This is the first case of Denys Drash Syndrome with the uncommon missense c.1097G>A [p.(Arg366His)] mutation in the WT1 gene which has been diagnosed on long-term stored formalin-fixed paraffin-embedded tissue in 1993. This emphasizes the importance of retained and adequately stored tissue as a resource in the ongoing medical care and counseling.


Assuntos
Síndrome de Denys-Drash/genética , Genes do Tumor de Wilms , Síndrome Nefrótica/diagnóstico , Síndrome Nefrótica/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Mutação de Sentido Incorreto , Inclusão em Parafina , Fixação de Tecidos , Proteínas WT1/genética
19.
Am J Med Genet A ; 170(3): 610-4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26553706

RESUMO

Facial characteristics, short stature, and skeletal anomalies have been described for the clinical diagnosis of Kabuki Syndrome (KS) in children. However, no studies have investigated body proportions in KS. Knowledge of body proportions in KS may contribute to better insight into the growth pattern and characterization of this genetic disorder. Therefore we compared body proportions of children with KS to normally proportioned controls to investigate if atypical body proportions are part of this genetic disorder. This study was designed and conducted within the setting of the Maastricht University Medical Centre (MUMC+), the official Dutch expert center for Kabuki syndrome. We conducted a cross-sectional study in 32 children (11 children with KS and 21 controls). Body proportions were determined by means of photogrammetric anthropometry, measurements based on digital photography. Body proportions, quantified as body ratios, differ significantly in children with KS from normally proportioned children. Children with KS have larger heads and longer arms proportional to their trunks and have been found to have longer upper arms proportional to their tibia length and feet. Based on deviations in body proportions it was shown possible to discern children with KS from normally proportioned controls.


Assuntos
Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Constituição Corporal/genética , Proteínas de Ligação a DNA/genética , Face/anormalidades , Doenças Hematológicas/diagnóstico , Doenças Hematológicas/genética , Proteínas de Neoplasias/genética , Doenças Vestibulares/diagnóstico , Doenças Vestibulares/genética , Anormalidades Múltiplas/fisiopatologia , Antropometria , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos Transversais , Face/fisiopatologia , Feminino , Expressão Gênica , Doenças Hematológicas/fisiopatologia , Humanos , Masculino , Mutação , Doenças Vestibulares/fisiopatologia
20.
Orphanet J Rare Dis ; 10: 44, 2015 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-25886057

RESUMO

BACKGROUND: Heterozygous loss-of-function mutations in the X-linked CASK gene cause progressive microcephaly with pontine and cerebellar hypoplasia (MICPCH) and severe intellectual disability (ID) in females. Different CASK mutations have also been reported in males. The associated phenotypes range from nonsyndromic ID to Ohtahara syndrome with cerebellar hypoplasia. However, the phenotypic spectrum in males has not been systematically evaluated to date. METHODS: We identified a CASK alteration in 8 novel unrelated male patients by targeted Sanger sequencing, copy number analysis (MLPA and/or FISH) and array CGH. CASK transcripts were investigated by RT-PCR followed by sequencing. Immunoblotting was used to detect CASK protein in patient-derived cells. The clinical phenotype and natural history of the 8 patients and 28 CASK-mutation positive males reported previously were reviewed and correlated with available molecular data. RESULTS: CASK alterations include one nonsense mutation, one 5-bp deletion, one mutation of the start codon, and five partial gene deletions and duplications; seven were de novo, including three somatic mosaicisms, and one was familial. In three subjects, specific mRNA junction fragments indicated in tandem duplication of CASK exons disrupting the integrity of the gene. The 5-bp deletion resulted in multiple aberrant CASK mRNAs. In fibroblasts from patients with a CASK loss-of-function mutation, no CASK protein could be detected. Individuals who are mosaic for a severe CASK mutation or carry a hypomorphic mutation still showed detectable amount of protein. CONCLUSIONS: Based on eight novel patients and all CASK-mutation positive males reported previously three phenotypic groups can be distinguished that represent a clinical continuum: (i) MICPCH with severe epileptic encephalopathy caused by hemizygous loss-of-function mutations, (ii) MICPCH associated with inactivating alterations in the mosaic state or a partly penetrant mutation, and (iii) syndromic/nonsyndromic mild to severe ID with or without nystagmus caused by CASK missense and splice mutations that leave the CASK protein intact but likely alter its function or reduce the amount of normal protein. Our findings facilitate focused testing of the CASK gene and interpreting sequence variants identified by next-generation sequencing in cases with a phenotype resembling either of the three groups.


Assuntos
Guanilato Quinases/genética , Microcefalia/enzimologia , Adolescente , Adulto , Cerebelo/anormalidades , Cerebelo/enzimologia , Criança , Pré-Escolar , Deficiências do Desenvolvimento/enzimologia , Deficiências do Desenvolvimento/etiologia , Deficiências do Desenvolvimento/genética , Humanos , Lactente , Deficiência Intelectual/enzimologia , Deficiência Intelectual/etiologia , Deficiência Intelectual/genética , Masculino , Microcefalia/complicações , Microcefalia/genética , Pessoa de Meia-Idade , Mutação , Malformações do Sistema Nervoso/enzimologia , Malformações do Sistema Nervoso/etiologia , Malformações do Sistema Nervoso/genética , Fenótipo , Adulto Jovem
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