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1.
Genet Med ; 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31578471

RESUMO

PURPOSE: Lamb-Shaffer syndrome (LAMSHF) is a neurodevelopmental disorder described in just over two dozen patients with heterozygous genetic alterations involving SOX5, a gene encoding a transcription factor regulating cell fate and differentiation in neurogenesis and other discrete developmental processes. The genetic alterations described so far are mainly microdeletions. The present study was aimed at increasing our understanding of LAMSHF, its clinical and genetic spectrum, and the pathophysiological mechanisms involved. METHODS: Clinical and genetic data were collected through GeneMatcher and clinical or genetic networks for 41 novel patients harboring various types of SOX5 alterations. Functional consequences of selected substitutions were investigated. RESULTS: Microdeletions and truncating variants occurred throughout SOX5. In contrast, most missense variants clustered in the pivotal SOX-specific high-mobility-group domain. The latter variants prevented SOX5 from binding DNA and promoting transactivation in vitro, whereas missense variants located outside the high-mobility-group domain did not. Clinical manifestations and severity varied among patients. No clear genotype-phenotype correlations were found, except that missense variants outside the high-mobility-group domain were generally better tolerated. CONCLUSIONS: This study extends the clinical and genetic spectrum associated with LAMSHF and consolidates evidence that SOX5 haploinsufficiency leads to variable degrees of intellectual disability, language delay, and other clinical features.

2.
Hum Mutat ; 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31513310

RESUMO

Developmental and epileptic encephalopathies (DEE) refer to a heterogeneous group of devastating neurodevelopmental disorders. Variants in KCNB1 have been recently reported in patients with early-onset DEE. KCNB1 encodes the α subunit of the delayed rectifier voltage-dependent potassium channel Kv 2.1. We review the 37 previously reported patients carrying 29 distinct KCNB1 variants and significantly expand the mutational spectrum describing 18 novel variants from 27 unreported patients. Most variants occur de novo and mainly consist of missense variants located on the voltage sensor and the pore domain of Kv 2.1. We also report the first inherited variant (p.Arg583*). KCNB1-related encephalopathies encompass a wide spectrum of neurodevelopmental disorders with predominant language difficulties and behavioral impairment. Eighty-five percent of patients developed epilepsies with variable syndromes and prognosis. Truncating variants in the C-terminal domain are associated with a less-severe epileptic phenotype. Overall, this report provides an up-to-date review of the mutational and clinical spectrum of KCNB1, strengthening its place as a causal gene in DEEs and emphasizing the need for further functional studies to unravel the underlying mechanisms.

3.
Nat Genet ; 50(10): 1442-1451, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30224647

RESUMO

The etiological spectrum of ultra-rare developmental disorders remains to be fully defined. Chromatin regulatory mechanisms maintain cellular identity and function, where misregulation may lead to developmental defects. Here, we report pathogenic variations in MSL3, which encodes a member of the chromatin-associated male-specific lethal (MSL) complex responsible for bulk histone H4 lysine 16 acetylation (H4K16ac) in flies and mammals. These variants cause an X-linked syndrome affecting both sexes. Clinical features of the syndrome include global developmental delay, progressive gait disturbance, and recognizable facial dysmorphism. MSL3 mutations affect MSL complex assembly and activity, accompanied by a pronounced loss of H4K16ac levels in vivo. Patient-derived cells display global transcriptome alterations of pathways involved in morphogenesis and cell migration. Finally, we use histone deacetylase inhibitors to rebalance acetylation levels, alleviating some of the molecular and cellular phenotypes of patient cells. Taken together, we characterize a syndrome that allowed us to decipher the developmental importance of MSL3 in humans.

4.
Eur J Hum Genet ; 26(7): 996-1006, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29695756

RESUMO

High-throughput sequencing (HTS) of human genome coding regions allows the simultaneous screen of a large number of genes, significantly improving the diagnosis of non-syndromic intellectual disabilities (ID). HTS studies permit the redefinition of the phenotypical spectrum of known disease-causing genes, escaping the clinical inclusion bias of gene-by-gene Sanger sequencing. We studied a cohort of 903 patients with ID not reminiscent of a well-known syndrome, using an ID-targeted HTS of several hundred genes and found de novo heterozygous variants in TCF4 (transcription factor 4) in eight novel patients. Piecing together the patients from this study and those from previous large-scale unbiased HTS studies, we estimated the rate of individuals with ID carrying a disease-causing TCF4 mutation to 0.7%. So far, TCF4 molecular abnormalities were known to cause a syndromic form of ID, Pitt-Hopkins syndrome (PTHS), which combines severe ID, developmental delay, absence of speech, behavioral and ventilation disorders, and a distinctive facial gestalt. Therefore, we reevaluated ten patients carrying a pathogenic or likely pathogenic variant in TCF4 (eight patients included in this study and two from our previous ID-HTS study) for PTHS criteria defined by Whalen and Marangi. A posteriori, five patients had a score highly evocative of PTHS, three were possibly consistent with this diagnosis, and two had a score below the defined PTHS threshold. In conclusion, these results highlight TCF4 as a frequent cause of moderate to profound ID and broaden the clinical spectrum associated to TCF4 mutations to nonspecific ID.

5.
J Med Genet ; 55(6): 422-429, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29459493

RESUMO

BACKGROUND: Segmentation defects of the vertebrae (SDV) are non-specific features found in various syndromes. The molecular bases of SDV are not fully elucidated due to the wide range of phenotypes and classification issues. The genes involved are in the Notch signalling pathway, which is a key system in somitogenesis. Here we report on mutations identified in a diagnosis cohort of SDV. We focused on spondylocostal dysostosis (SCD) and the phenotype of these patients in order to establish a diagnostic strategy when confronted with SDV. PATIENTS AND METHODS: We used DNA samples from a cohort of 73 patients and performed targeted sequencing of the five known SCD-causing genes (DLL3, MESP2, LFNG, HES7 and TBX6) in the first 48 patients and whole-exome sequencing (WES) in 28 relevant patients. RESULTS: Ten diagnoses, including four biallelic variants in TBX6, two biallelic variants in LFNG and DLL3, and one in MESP2 and HES7, were made with the gene panel, and two diagnoses, including biallelic variants in FLNB and one variant in MEOX1, were made by WES. The diagnostic yield of the gene panel was 10/73 (13.7%) in the global cohort but 8/10 (80%) in the subgroup meeting the SCD criteria; the diagnostic yield of WES was 2/28 (8%). CONCLUSION: After negative array CGH, targeted sequencing of the five known SCD genes should only be performed in patients who meet the diagnostic criteria of SCD. The low proportion of candidate genes identified by WES in our cohort suggests the need to consider more complex genetic architectures in cases of SDV.

6.
Am J Med Genet C Semin Med Genet ; 175(4): 417-430, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29178447

RESUMO

CHARGE syndrome (CS) is a genetic disorder whose first description included Coloboma, Heart disease, Atresia of choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies and deafness, most often caused by a genetic mutation in the CHD7 gene. Two features were then added: semicircular canal anomalies and arhinencephaly/olfactory bulb agenesis, with classification of typical, partial, or atypical forms on the basis of major and minor clinical criteria. The detection rate of a pathogenic variant in the CHD7 gene varies from 67% to 90%. To try to have an overview of this heterogenous clinical condition and specify a genotype-phenotype relation, we conducted a national study of phenotype and genotype in 119 patients with CS. Selected clinical diagnostic criteria were from Verloes (2005), updated by Blake & Prasad (). Besides obtaining a detailed clinical description, when possible, patients underwent a full ophthalmologic examination, audiometry, temporal bone CT scan, gonadotropin analysis, and olfactory-bulb MRI. All patients underwent CHD7 sequencing and MLPA analysis. We found a pathogenic CHD7 variant in 83% of typical CS cases and 58% of atypical cases. Pathogenic variants in the CHD7 gene were classified by the expected impact on the protein. In all, 90% of patients had a typical form of CS and 10% an atypical form. The most frequent features were deafness/semicircular canal hypoplasia (94%), pituitary defect/hypogonadism (89%), external ear anomalies (87%), square-shaped face (81%), and arhinencephaly/anosmia (80%). Coloboma (73%), heart defects (65%), and choanal atresia (43%) were less frequent.


Assuntos
Síndrome CHARGE/diagnóstico , Síndrome CHARGE/genética , Estudos de Associação Genética , Genótipo , Fenótipo , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Adolescente , Adulto , Alelos , Substituição de Aminoácidos , Sistema Nervoso Central/anormalidades , Criança , Pré-Escolar , Estudos de Coortes , Nervos Cranianos/anormalidades , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Feminino , França , Testes Genéticos , Humanos , Lactente , Masculino , Técnicas de Diagnóstico Molecular , Adulto Jovem
7.
Eur J Hum Genet ; 25(5): 552-559, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28327570

RESUMO

PUF60 encodes a nucleic acid-binding protein, a component of multimeric complexes regulating RNA splicing and transcription. In 2013, patients with microdeletions of chromosome 8q24.3 including PUF60 were found to have developmental delay, microcephaly, craniofacial, renal and cardiac defects. Very similar phenotypes have been described in six patients with variants in PUF60, suggesting that it underlies the syndrome. We report 12 additional patients with PUF60 variants who were ascertained using exome sequencing: six through the Deciphering Developmental Disorders Study and six through similar projects. Detailed phenotypic analysis of all patients was undertaken. All 12 patients had de novo heterozygous PUF60 variants on exome analysis, each confirmed by Sanger sequencing: four frameshift variants resulting in premature stop codons, three missense variants that clustered within the RNA recognition motif of PUF60 and five essential splice-site (ESS) variant. Analysis of cDNA from a fibroblast cell line derived from one of the patients with an ESS variants revealed aberrant splicing. The consistent feature was developmental delay and most patients had short stature. The phenotypic variability was striking; however, we observed similarities including spinal segmentation anomalies, congenital heart disease, ocular colobomata, hand anomalies and (in two patients) unilateral renal agenesis/horseshoe kidney. Characteristic facial features included micrognathia, a thin upper lip and long philtrum, narrow almond-shaped palpebral fissures, synophrys, flared eyebrows and facial hypertrichosis. Heterozygote loss-of-function variants in PUF60 cause a phenotype comprising growth/developmental delay and craniofacial, cardiac, renal, ocular and spinal anomalies, adding to disorders of human development resulting from aberrant RNA processing/spliceosomal function.


Assuntos
Anormalidades Múltiplas/genética , Deficiência Intelectual/genética , Microcefalia/genética , Mutação de Sentido Incorreto , Fatores de Processamento de RNA/genética , Proteínas Repressoras/genética , Anormalidades Múltiplas/diagnóstico , Células Cultivadas , Criança , Códon de Terminação/genética , Exoma , Feminino , Heterozigoto , Humanos , Deficiência Intelectual/diagnóstico , Masculino , Microcefalia/diagnóstico , Fenótipo , Síndrome
8.
Eur J Hum Genet ; 25(4): 423-431, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28176767

RESUMO

Fragile-X syndrome (FXS) is a frequent genetic form of intellectual disability (ID). The main recurrent mutagenic mechanism causing FXS is the expansion of a CGG repeat sequence in the 5'-UTR of the FMR1 gene, therefore, routinely tested in ID patients. We report here three FMR1 intragenic pathogenic variants not affecting this sequence, identified using high-throughput sequencing (HTS): a previously reported hemizygous deletion encompassing the last exon of FMR1, too small to be detected by array-CGH and inducing decreased expression of a truncated form of FMRP protein, in three brothers with ID (family 1) and two splice variants in boys with sporadic ID: a de novo variant c.990+1G>A (family 2) and a maternally inherited c.420-8A>G variant (family 3). After clinical reevaluation, the five patients presented features consistent with FXS (mean Hagerman's scores=15). We conducted a systematic review of all rare non-synonymous variants previously reported in FMR1 in ID patients and showed that six of them are convincing pathogenic variants. This study suggests that intragenic FMR1 variants, although much less frequent than CGG expansions, are a significant mutational mechanism leading to FXS and demonstrates the interest of HTS approaches to detect them in ID patients with a negative standard work-up.


Assuntos
Proteína do X Frágil de Retardo Mental/genética , Síndrome do Cromossomo X Frágil/genética , Mutação , Feminino , Síndrome do Cromossomo X Frágil/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Processamento de RNA , Irmãos
9.
Am J Med Genet A ; 173(1): 62-71, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27615324

RESUMO

Neutropenia can be qualified as congenital when of neonatal onset or when associated with extra-hematopoietic manifestations. Overall, 30% of patients with congenital neutropenia (CN) remain without a molecular diagnosis after a multidisciplinary consultation and tedious diagnostic strategy. In the rare situations when neutropenia is identified and associated with intellectual disability (ID), there are few diagnostic hypotheses to test. This retrospective multicenter study reports on a clinically heterogeneous cohort of 10 unrelated patients with CN associated with ID and no molecular diagnosis prior to whole-exome sequencing (WES). WES provided a diagnostic yield of 40% (4/10). The results suggested that in many cases neutropenia and syndromic manifestations could not be assigned to the same molecular alteration. Three sub-groups of patients were highlighted: (i) severe, symptomatic chronic neutropenia, detected early in life, and related to a known mutation in the CN spectrum (ELANE); (ii) mild to moderate benign intermittent neutropenia, detected later, and associated with mutations in genes implicated in neurodevelopmental disorders (CHD2, HUWE1); and (iii) moderate to severe intermittent neutropenia as a probably undiagnosed feature of a newly reported syndrome (KAT6A). Unlike KAT6A, which seems to be associated with a syndromic form of CN, the other reported mutations may not explain the entire clinical picture. Although targeted gene sequencing can be discussed for the primary diagnosis of severe CN, we suggest that performing WES for the diagnosis of disorders associating CN with ID will not only provide the etiological diagnosis but will also pave the way towards personalized care and follow-up. © 2016 Wiley Periodicals, Inc.


Assuntos
Exoma , Sequenciamento de Nucleotídeos em Larga Escala , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Neutropenia/congênito , Adolescente , Biomarcadores , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Humanos , Lactente , Masculino , Neutropenia/diagnóstico , Neutropenia/genética , Fenótipo , Estudos Retrospectivos , Síndrome
11.
Eur J Hum Genet ; 25(1): 43-51, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-27804958

RESUMO

Verheij syndrome, also called 8q24.3 microdeletion syndrome, is a rare condition characterized by ante- and postnatal growth retardation, microcephaly, vertebral anomalies, joint laxity/dislocation, developmental delay (DD), cardiac and renal defects and dysmorphic features. Recently, PUF60 (Poly-U Binding Splicing Factor 60 kDa), which encodes a component of the spliceosome, has been discussed as the best candidate gene for the Verheij syndrome phenotype, regarding the cardiac and short stature phenotype. To date, only one patient has been reported with a de novo variant in PUF60 that probably affects function (c.505C>T leading to p.(His169Tyr)) associated with DD, microcephaly, craniofacial and cardiac defects. Additional patients were required to confirm the pathogenesis of this association and further delineate the clinical spectrum. Here we report five patients with de novo heterozygous variants in PUF60 identified using whole exome sequencing. Variants included a splice-site variant (c.24+1G>C), a frameshift variant (p.(Ile136Thrfs*31)), two nonsense variants (p.(Arg448*) and p.(Lys301*)) and a missense change (p.(Val483Ala)). All six patients with a PUF60 variant (the five patients of the present study and the unique reported patient) have the same core facial gestalt as 8q24.3 microdeletions patients, associated with DD. Other findings include feeding difficulties (3/6), cardiac defects (5/6), short stature (5/6), joint laxity and/or dislocation (5/6), vertebral anomalies (3/6), bilateral microphthalmia and irido-retinal coloboma (1/6), bilateral optic nerve hypoplasia (2/6), renal anomalies (2/6) and branchial arch defects (2/6). These results confirm that PUF60 is a major driver for the developmental, craniofacial, skeletal and cardiac phenotypes associated with the 8q24.3 microdeletion.


Assuntos
Nanismo/genética , Cardiopatias Congênitas/genética , Deficiência Intelectual/genética , Fatores de Processamento de RNA/genética , Proteínas Repressoras/genética , Adolescente , Criança , Pré-Escolar , Deleção Cromossômica , Cromossomos Humanos Par 8/genética , Nanismo/fisiopatologia , Exoma/genética , Feminino , Mutação da Fase de Leitura , Cardiopatias Congênitas/fisiopatologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Deficiência Intelectual/fisiopatologia , Masculino , Fenótipo , Processamento de RNA/genética
12.
Eur J Hum Genet ; 24(7): 992-1000, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26626311

RESUMO

Heterozygous COL2A1 variants cause a wide spectrum of skeletal dysplasia termed type II collagenopathies. We assessed the impact of this gene in our French series. A decision tree was applied to select 136 probands (71 Stickler cases, 21 Spondyloepiphyseal dysplasia congenita cases, 11 Kniest dysplasia cases, and 34 other dysplasia cases) before molecular diagnosis by Sanger sequencing. We identified 66 different variants among the 71 positive patients. Among those patients, 18 belonged to multiplex families and 53 were sporadic. Most variants (38/44, 86%) were located in the triple helical domain of the collagen chain and glycine substitutions were mainly observed in severe phenotypes, whereas arginine to cysteine changes were more often encountered in moderate phenotypes. This series of skeletal dysplasia is one of the largest reported so far, adding 44 novel variants (15%) to published data. We have confirmed that about half of our Stickler patients (46%) carried a COL2A1 variant, and that the molecular spectrum was different across the phenotypes. To further address the question of genotype-phenotype correlation, we plan to screen our patients for other candidate genes using a targeted next-generation sequencing approach.


Assuntos
Substituição de Aminoácidos , Artrite/genética , Doenças do Colágeno/genética , Colágeno Tipo II/genética , Doenças do Tecido Conjuntivo/genética , Perda Auditiva Neurossensorial/genética , Osteocondrodisplasias/genética , Fenótipo , Descolamento Retiniano/genética , Artrite/patologia , Doenças do Colágeno/patologia , Colágeno Tipo II/química , Doenças do Tecido Conjuntivo/patologia , Feminino , Perda Auditiva Neurossensorial/patologia , Humanos , Masculino , Osteocondrodisplasias/patologia , Linhagem , Domínios Proteicos , Descolamento Retiniano/patologia
13.
Am J Med Genet A ; 170A(1): 116-29, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26420639

RESUMO

Xq28 duplications encompassing MECP2 have been described in male patients with a severe neurodevelopmental disorder associated with hypotonia and spasticity, severe learning disability, stereotyped movements, and recurrent pulmonary infections. We report on standardized brain magnetic resonance imaging (MRI) data of 30 affected patients carrying an Xq28 duplication involving MECP2 of various sizes (228 kb to 11.7 Mb). The aim of this study was to seek recurrent malformations and attempt to determine whether variations in imaging features could be explained by differences in the size of the duplications. We showed that 93% of patients had brain MRI abnormalities such as corpus callosum abnormalities (n = 20), reduced volume of the white matter (WM) (n = 12), ventricular dilatation (n = 9), abnormal increased hyperintensities on T2-weighted images involving posterior periventricular WM (n = 6), and vermis hypoplasia (n = 5). The occipitofrontal circumference varied considerably between >+2SD in five patients and <-2SD in four patients. Among the nine patients with dilatation of the lateral ventricles, six had a duplication involving L1CAM. The only patient harboring bilateral posterior subependymal nodular heterotopia also carried an FLNA gene duplication. We could not demonstrate a correlation between periventricular WM hyperintensities/delayed myelination and duplication of the IKBKG gene. We thus conclude that patients with an Xq28 duplication involving MECP2 share some similar but non-specific brain abnormalities. These imaging features, therefore, could not constitute a diagnostic clue. The genotype-phenotype correlation failed to demonstrate a relationship between the presence of nodular heterotopia, ventricular dilatation, WM abnormalities, and the presence of FLNA, L1CAM, or IKBKG, respectively, in the duplicated segment.


Assuntos
Encefalopatias/genética , Cromossomos Humanos X/genética , Duplicação Gênica , Imagem por Ressonância Magnética/métodos , Retardo Mental Ligado ao Cromossomo X/genética , Proteína 2 de Ligação a Metil-CpG/genética , Adolescente , Adulto , Encefalopatias/patologia , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Retardo Mental Ligado ao Cromossomo X/patologia , Pessoa de Meia-Idade , Linhagem , Fenótipo , Prognóstico , Adulto Jovem
14.
Eur J Hum Genet ; 24(6): 830-7, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26395556

RESUMO

The increasing use of array-CGH in malformation syndromes with intellectual disability could lead to the description of new contiguous gene syndrome by the analysis of the gene content of the microdeletion and reverse phenotyping. Thanks to a national and international call for collaboration by Achropuce and Decipher, we recruited four patients carrying de novo overlapping deletions of chromosome 9q33.3q34.11, including the STXBP1, the LMX1B and the ENG genes. We restrained the selection to these three genes because the effects of their haploinsufficency are well described in the literature and easily recognizable clinically. All deletions were detected by array-CGH and confirmed by FISH. The patients display common clinical features, including intellectual disability with epilepsy, owing to the presence of STXBP1 within the deletion, nail dysplasia and bone malformations, in particular patellar abnormalities attributed to LMX1B deletion, epistaxis and cutaneous-mucous telangiectasias explained by ENG haploinsufficiency and common facial dysmorphism. This systematic analysis of the genes comprised in the deletion allowed us to identify genes whose haploinsufficiency is expected to lead to disease manifestations and complications that require personalized follow-up, in particular for renal, eye, ear, vascular and neurological manifestations.


Assuntos
Deleção Cromossômica , Anormalidades Craniofaciais/genética , Endoglina/genética , Epilepsia/genética , Deficiência Intelectual/genética , Proteínas com Homeodomínio LIM/genética , Proteínas Munc18/genética , Fatores de Transcrição/genética , Adolescente , Criança , Cromossomos Humanos Par 9/genética , Anormalidades Craniofaciais/diagnóstico , Epilepsia/diagnóstico , Feminino , Haploinsuficiência , Humanos , Deficiência Intelectual/diagnóstico , Masculino , Fenótipo , Síndrome
15.
Eur J Hum Genet ; 24(6): 911-8, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26486473

RESUMO

Learning disabilities (LDs) are a clinically and genetically heterogeneous group of diseases. Array-CGH and high-throughput sequencing have dramatically expanded the number of genes implicated in isolated intellectual disabilities and LDs, highlighting the implication of neuron-specific post-mitotic transcription factors and synaptic proteins as candidate genes. We report a unique family diagnosed with autosomal dominant learning disability and a 6p21 microdeletion segregating in three patients. The 870 kb microdeletion encompassed the brain-expressed gene LRFN2, which encodes for a synaptic cell adhesion molecule. Neuropsychological assessment identified selective working memory deficits, with borderline intellectual functioning. Further investigations identified a defect in executive function, and auditory-verbal processes. These data were consistent with brain MRI and FDG-PET functional brain imaging, which, when compared with controls, revealed abnormal brain volume and hypometabolism of gray matter structures implicated in working memory. We performed electron microscopy immunogold labeling demonstrating the localization of LRFN2 at synapses of cerebellar and hippocampal rat neurons, often associated with the NR1 subunit of N-methyl-D-aspartate receptors (NMDARs). Altogether, the combined approaches imply a role for LRFN2 in LD, specifically for working memory processes and executive function. In conclusion, the identification of familial cases of clinically homogeneous endophenotypes of LD might help in both the management of patients and genetic counseling for families.


Assuntos
Deleção de Genes , Transtornos de Aprendizagem/genética , Proteínas de Membrana/genética , Transtornos da Memória/genética , Memória de Curto Prazo , Adulto , Animais , Encéfalo/diagnóstico por imagem , Células Cultivadas , Criança , Feminino , Fluordesoxiglucose F18 , Heterozigoto , Humanos , Transtornos de Aprendizagem/complicações , Transtornos de Aprendizagem/diagnóstico , Imagem por Ressonância Magnética , Masculino , Proteínas de Membrana/metabolismo , Transtornos da Memória/complicações , Transtornos da Memória/diagnóstico , Linhagem , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo , Sinapses/metabolismo , Sinapses/ultraestrutura
16.
Eur J Hum Genet ; 24(1): 99-105, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25873010

RESUMO

To determine if the at-risk single-nucleotide polymorphism (SNP) alleles for colorectal cancer (CRC) could contribute to clinical situations suggestive of an increased genetic risk for CRC, we performed a prospective national case-control study based on highly selected patients (CRC in two first-degree relatives, one before 61 years of age; or CRC diagnosed before 51 years of age; or multiple primary CRCs, the first before 61 years of age; exclusion of Lynch syndrome and polyposes) and controls without personal or familial history of CRC. SNPs were genotyped using SNaPshot, and statistical analyses were performed using Pearson's χ(2) test, Cochran-Armitage test of trend and logistic regression. We included 1029 patients and 350 controls. We confirmed the association of CRC risk with four SNPs, with odds ratio (OR) higher than previously reported: rs16892766 on 8q23.3 (OR: 1.88, 95% confidence interval (CI): 1.30-2.72; P=0.0007); rs4779584 on 15q13.3 (OR: 1.42, CI: 1.11-1.83; P=0.0061) and rs4939827 and rs58920878/Novel 1 on 18q21.1 (OR: 1.49, CI: 1.13-1.98; P=0.007 and OR: 1.49, CI: 1.14-1.95; P=0.0035). We found a significant (P<0.0001) cumulative effect of the at-risk alleles or genotypes with OR at 1.62 (CI: 1.10-2.37), 2.09 (CI: 1.43-3.07), 2.87 (CI: 1.76-4.70) and 3.88 (CI: 1.72-8.76) for 1, 2, 3 and at least 4 at-risk alleles, respectively, and OR at 1.71 (CI: 1.18-2.46), 2.29 (CI: 1.55-3.38) and 6.21 (CI: 2.67-14.42) for 1, 2 and 3 at-risk genotypes, respectively. Combination of SNPs may therefore explain a fraction of clinical situations suggestive of an increased risk for CRC.


Assuntos
Cromossomos Humanos Par 15 , Cromossomos Humanos Par 18 , Cromossomos Humanos Par 8 , Neoplasias Colorretais/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Adulto , Alelos , Estudos de Casos e Controles , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Feminino , Frequência do Gene , Loci Gênicos , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estudos Prospectivos , Fatores de Risco
17.
Mol Cytogenet ; 8: 42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26110021

RESUMO

BACKGROUND: Prader-Willi syndrome (PWS) is characterized by hypotonia, delayed neuropsychomotor development, overeating, obesity and mental deficiency. This phenotype is encountered in other conditions, defining Prader-Willi-like syndrome (PWLS). CASE PRESENTATION: We report a 14-year-old boy with a complex small supernumerary marker chromosome (sSMC) associated with PWLS. The propositus presents clinical features commonly found in patients with PWLS, including growth hormone deficit. Banding karyotype analysis and fluorescence in situ hybridization (FISH) revealed a marker derived from chromosome 6 and a neocentromere as suspected, but array-CGH enabled us to characterize this marker as a der(10)t(6;10)(6qter → 6q23.3::10p11.1 → 10p11.21)dn. As far as we know, this is the first diagnosed case of PWLS associated with a complex sSMC, involving a 30.9 Mb gain in the 6q16.3q23.3 region and a 3.5 Mb gain in the 10p11.21p11.1 region. Several genes have been mapped to the 6q region including the TCBA1 gene, which is associated with developmental delay and recurrent infections, the ENPP1 gene, associated with insulin resistance and susceptibility to obesity and the BMIQ3 gene, associated with body mass index (BMI). No OMIM gene was found in the smallest 10p11.21p11.1 region. CONCLUSIONS: We suggest that the duplicated chromosome segment 6q16.3q23.3 may be responsible for the phenotype of our case and may also be a candidate locus of PWLS.

18.
Prenat Diagn ; 35(7): 675-84, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25754886

RESUMO

OBJECTIVES: Conradi-Hünermann-Happle [X-linked dominant chondrodysplasia punctata 2 (CDPX2)] syndrome is a rare X-linked dominant skeletal dysplasia usually lethal in men while affected women show wide clinical heterogeneity. Different EBP mutations have been reported. Severe female cases have rarely been reported, with only six antenatal presentations. METHODS: To better characterize the phenotype in female fetuses, we included nine antenatally diagnosed cases of women with EBP mutations. All cases were de novo except for two fetuses with an affected mother and one case of germinal mosaicism. RESULTS: The mean age at diagnosis was 22 weeks of gestation. The ultrasound features mainly included bone abnormalities: shortening (8/9 cases) and bowing of the long bones (5/9), punctuate epiphysis (7/9) and an irregular aspect of the spine (5/9). Postnatal X-rays and examination showed ichthyosis (8/9) and epiphyseal stippling (9/9), with frequent asymmetric short and bowed long bones. The X-inactivation pattern of the familial case revealed skewed X-inactivation in the mildly symptomatic mother and random X-inactivation in the severe fetal case. Differently affected skin samples of the same fetus revealed different patterns of X-inactivation. CONCLUSION: Prenatal detection of asymmetric shortening and bowing of the long bones and cartilage stippling should raise the possibility of CPDX2 in female fetuses, especially because the majority of such cases involve de novo mutations.


Assuntos
Condrodisplasia Punctata/diagnóstico por imagem , Fenótipo , Índice de Gravidade de Doença , Ultrassonografia Pré-Natal , Condrodisplasia Punctata/genética , Feminino , Marcadores Genéticos , Testes Genéticos , Humanos , Recém-Nascido , Mutação , Gravidez , Segundo Trimestre da Gravidez , Radiografia , Estudos Retrospectivos , Esteroide Isomerases/genética , Inativação do Cromossomo X
19.
J Clin Immunol ; 35(2): 168-81, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25721700

RESUMO

MECP2 (methyl CpG binding protein 2) duplication causes syndromic intellectual disability. Patients often suffer from life-threatening infections, suggesting an additional immunodeficiency. We describe for the first time the detailed infectious and immunological phenotype of MECP2 duplication syndrome. 17/27 analyzed patients suffered from pneumonia, 5/27 from at least one episode of sepsis. Encapsulated bacteria (S.pneumoniae, H.influenzae) were frequently isolated. T-cell immunity showed no gross abnormalities in 14/14 patients and IFNy-secretion upon ConA-stimulation was not decreased in 6/7 patients. In 6/21 patients IgG2-deficiency was detected - in 4/21 patients accompanied by IgA-deficiency, 10/21 patients showed low antibody titers against pneumococci. Supra-normal IgG1-levels were detected in 11/21 patients and supra-normal IgG3-levels were seen in 8/21 patients - in 6 of the patients as combined elevation of IgG1 and IgG3. Three of the four patients with IgA/IgG2-deficiency developed multiple severe infections. Upon infections pronounced acute-phase responses were common: 7/10 patients showed CRP values above 200 mg/l. Our data for the first time show systematically that increased susceptibility to infections in MECP2 duplication syndrome is associated with IgA/IgG2-deficiency, low antibody titers against pneumococci and elevated acute-phase responses. So patients with MECP2 duplication syndrome and low IgA/IgG2 may benefit from prophylactic substitution of sIgA and IgG.


Assuntos
Duplicação Gênica , Infecção/etiologia , Retardo Mental Ligado ao Cromossomo X/complicações , Retardo Mental Ligado ao Cromossomo X/imunologia , Proteína 2 de Ligação a Metil-CpG/genética , Fenótipo , Proteínas da Fase Aguda/metabolismo , Adolescente , Adulto , Proteína C-Reativa/metabolismo , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Genótipo , Humanos , Imunidade Celular , Imunidade Humoral , Imunoglobulinas/sangue , Imunoglobulinas/imunologia , Infecção/diagnóstico , Infecção/tratamento farmacológico , Masculino , Retardo Mental Ligado ao Cromossomo X/diagnóstico , Pessoa de Meia-Idade , Adulto Jovem
20.
J Med Genet ; 51(11): 724-36, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25167861

RESUMO

BACKGROUND: Intellectual disability (ID) is characterised by an extreme genetic heterogeneity. Several hundred genes have been associated to monogenic forms of ID, considerably complicating molecular diagnostics. Trio-exome sequencing was recently proposed as a diagnostic approach, yet remains costly for a general implementation. METHODS: We report the alternative strategy of targeted high-throughput sequencing of 217 genes in which mutations had been reported in patients with ID or autism as the major clinical concern. We analysed 106 patients with ID of unknown aetiology following array-CGH analysis and other genetic investigations. Ninety per cent of these patients were males, and 75% sporadic cases. RESULTS: We identified 26 causative mutations: 16 in X-linked genes (ATRX, CUL4B, DMD, FMR1, HCFC1, IL1RAPL1, IQSEC2, KDM5C, MAOA, MECP2, SLC9A6, SLC16A2, PHF8) and 10 de novo in autosomal-dominant genes (DYRK1A, GRIN1, MED13L, TCF4, RAI1, SHANK3, SLC2A1, SYNGAP1). We also detected four possibly causative mutations (eg, in NLGN3) requiring further investigations. We present detailed reasoning for assigning causality for each mutation, and associated patients' clinical information. Some genes were hit more than once in our cohort, suggesting they correspond to more frequent ID-associated conditions (KDM5C, MECP2, DYRK1A, TCF4). We highlight some unexpected genotype to phenotype correlations, with causative mutations being identified in genes associated to defined syndromes in patients deviating from the classic phenotype (DMD, TCF4, MECP2). We also bring additional supportive (HCFC1, MED13L) or unsupportive (SHROOM4, SRPX2) evidences for the implication of previous candidate genes or mutations in cognitive disorders. CONCLUSIONS: With a diagnostic yield of 25% targeted sequencing appears relevant as a first intention test for the diagnosis of ID, but importantly will also contribute to a better understanding regarding the specific contribution of the many genes implicated in ID and autism.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Técnicas de Diagnóstico Molecular/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Análise Mutacional de DNA/métodos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Análise de Sequência de DNA/métodos , Adulto Jovem
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