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1.
Hum Brain Mapp ; 40(7): 2125-2142, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30653778

RESUMO

The execution of coordinated hand movements requires complex interactions between premotor and primary motor areas in the two hemispheres. The supplementary motor area (SMA) is involved in movement preparation and bimanual coordination. How the SMA controls bimanual coordination remains unclear, although there is evidence suggesting that the SMA could modulate interhemispheric interactions. With a delayed-response task, we investigated interhemispheric interactions underlying normal movement preparation and the role of the SMA in these interactions during the delay period of unimanual or bimanual hand movements. We used functional MRI and transcranial magnetic stimulation in 22 healthy volunteers (HVs), and then in two models of SMA dysfunction: (a) in the same group of HVs after transient disruption of the right SMA proper by continuous transcranial magnetic theta-burst stimulation; (b) in a group of 22 patients with congenital mirror movements (CMM), whose inability to produce asymmetric hand movements is associated with SMA dysfunction. In HVs, interhemispheric connectivity during the delay period was modulated according to whether or not hand coordination was required for the forthcoming movement. In HVs following SMA disruption and in CMM patients, interhemispheric connectivity was modified during the delay period and the interhemispheric inhibition was decreased. Using two models of SMA dysfunction, we showed that the SMA modulates interhemispheric interactions during movement preparation. This unveils a new role for the SMA and highlights its importance in coordinated movement preparation.

2.
Hum Genet ; 2018 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-29974297

RESUMO

Two distinct syndromes arise from pathogenic variants in the X-linked gene BCOR (BCL-6 corepressor): oculofaciocardiodental (OFCD) syndrome, which affects females, and a severe microphthalmia ('Lenz'-type) syndrome affecting males. OFCD is an X-linked dominant syndrome caused by a variety of BCOR null mutations. As it manifests only in females, it is presumed to be lethal in males. The severe male X-linked recessive microphthalmia syndrome ('Lenz') usually includes developmental delay in addition to the eye findings and is caused by hypomorphic BCOR variants, mainly by a specific missense variant c.254C > T, p.(Pro85Leu). Here, we detail 16 new cases (11 females with 4 additional, genetically confirmed, affected female relatives; 5 male cases each with unaffected carrier mothers). We describe new variants and broaden the phenotypic description for OFCD to include neuropathy, muscle hypotonia, pituitary underdevelopment, brain atrophy, lipoma and the first description of childhood lymphoma in an OFCD case. Our male X-linked recessive cases show significant new phenotypes: developmental delay (without eye anomalies) in two affected half-brothers with a novel BCOR variant, and one male with high myopia, megalophthalmos, posterior embryotoxon, developmental delay, and heart and bony anomalies with a previously undescribed BCOR splice site variant. Our female OFCD cases and their affected female relatives showed variable features, but consistently had early onset cataracts. We show that a mosaic carrier mother manifested early cataract and dental anomalies. All female carriers of the male X-linked recessive cases for whom genetic confirmation was available showed skewed X-inactivation and were unaffected. In view of the extended phenotype, we suggest a new term of X-linked BCOR-related syndrome.

3.
4.
Nat Genet ; 49(4): 511-514, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28250454

RESUMO

Brain malformations involving the corpus callosum are common in children with developmental disabilities. We identified DCC mutations in four families and five sporadic individuals with isolated agenesis of the corpus callosum (ACC) without intellectual disability. DCC mutations result in variable dominant phenotypes with decreased penetrance, including mirror movements and ACC associated with a favorable developmental prognosis. Possible phenotypic modifiers include the type and location of mutation and the sex of the individual.


Assuntos
Agenesia do Corpo Caloso/genética , Deficiências do Desenvolvimento/genética , Mutação/genética , Receptores de Superfície Celular/genética , Proteínas Supressoras de Tumor/genética , Anormalidades Múltiplas/genética , Encéfalo/patologia , Corpo Caloso/patologia , Receptor DCC , Família , Feminino , Humanos , Masculino , Malformações do Sistema Nervoso/genética , Células-Tronco Neurais/patologia , Penetrância , Fenótipo
5.
Am J Hum Genet ; 98(5): 981-992, 2016 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-27108798

RESUMO

Gillespie syndrome (GS) is characterized by bilateral iris hypoplasia, congenital hypotonia, non-progressive ataxia, and progressive cerebellar atrophy. Trio-based exome sequencing identified de novo mutations in ITPR1 in three unrelated individuals with GS recruited to the Deciphering Developmental Disorders study. Whole-exome or targeted sequence analysis identified plausible disease-causing ITPR1 mutations in 10/10 additional GS-affected individuals. These ultra-rare protein-altering variants affected only three residues in ITPR1: Glu2094 missense (one de novo, one co-segregating), Gly2539 missense (five de novo, one inheritance uncertain), and Lys2596 in-frame deletion (four de novo). No clinical or radiological differences were evident between individuals with different mutations. ITPR1 encodes an inositol 1,4,5-triphosphate-responsive calcium channel. The homo-tetrameric structure has been solved by cryoelectron microscopy. Using estimations of the degree of structural change induced by known recessive- and dominant-negative mutations in other disease-associated multimeric channels, we developed a generalizable computational approach to indicate the likely mutational mechanism. This analysis supports a dominant-negative mechanism for GS variants in ITPR1. In GS-derived lymphoblastoid cell lines (LCLs), the proportion of ITPR1-positive cells using immunofluorescence was significantly higher in mutant than control LCLs, consistent with an abnormality of nuclear calcium signaling feedback control. Super-resolution imaging supports the existence of an ITPR1-lined nucleoplasmic reticulum. Mice with Itpr1 heterozygous null mutations showed no major iris defects. Purkinje cells of the cerebellum appear to be the most sensitive to impaired ITPR1 function in humans. Iris hypoplasia is likely to result from either complete loss of ITPR1 activity or structure-specific disruption of multimeric interactions.


Assuntos
Aniridia/etiologia , Aniridia/patologia , Ataxia Cerebelar/etiologia , Ataxia Cerebelar/patologia , Genes Dominantes/genética , Receptores de Inositol 1,4,5-Trifosfato/genética , Deficiência Intelectual/etiologia , Deficiência Intelectual/patologia , Mutação/genética , Adolescente , Adulto , Animais , Células Cultivadas , Criança , Feminino , Humanos , Receptores de Inositol 1,4,5-Trifosfato/química , Linfócitos/metabolismo , Linfócitos/patologia , Masculino , Camundongos , Microscopia Confocal , Pessoa de Meia-Idade , Linhagem , Conformação Proteica
6.
PLoS One ; 11(4): e0153757, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27124303

RESUMO

We report molecular genetic analysis of 42 affected individuals referred with a diagnosis of aniridia who previously screened as negative for intragenic PAX6 mutations. Of these 42, the diagnoses were 31 individuals with aniridia and 11 individuals referred with a diagnosis of Gillespie syndrome (iris hypoplasia, ataxia and mild to moderate developmental delay). Array-based comparative genomic hybridization identified six whole gene deletions: four encompassing PAX6 and two encompassing FOXC1. Six deletions with plausible cis-regulatory effects were identified: five that were 3' (telomeric) to PAX6 and one within a gene desert 5' (telomeric) to PITX2. Sequence analysis of the FOXC1 and PITX2 coding regions identified two plausibly pathogenic de novo FOXC1 missense mutations (p.Pro79Thr and p.Leu101Pro). No intragenic mutations were detected in PITX2. FISH mapping in an individual with Gillespie-like syndrome with an apparently balanced X;11 reciprocal translocation revealed disruption of a gene at each breakpoint: ARHGAP6 on the X chromosome and PHF21A on chromosome 11. In the other individuals with Gillespie syndrome no mutations were identified in either of these genes, or in HCCS which lies close to the Xp breakpoint. Disruption of PHF21A has previously been implicated in the causation of intellectual disability (but not aniridia). Plausibly causative mutations were identified in 15 out of 42 individuals (12/32 aniridia; 3/11 Gillespie syndrome). Fourteen of these mutations presented in the known aniridia genes; PAX6, FOXC1 and PITX2. The large number of individuals in the cohort with no mutation identified suggests greater locus heterogeneity may exist in both isolated and syndromic aniridia than was previously appreciated.


Assuntos
Aniridia/genética , Ataxia Cerebelar/genética , Deficiência Intelectual/genética , Fator de Transcrição PAX6/genética , Cromossomos Humanos Par 11/genética , Cromossomos Humanos X/genética , Hibridização Genômica Comparativa/métodos , Feminino , Fatores de Transcrição Forkhead/genética , Proteínas Ativadoras de GTPase/genética , Testes Genéticos/métodos , Histona Desacetilases/genética , Proteínas de Homeodomínio/genética , Humanos , Masculino , Mutação/genética , Fatores de Transcrição/genética
7.
Hum Mutat ; 37(8): 786-93, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27120018

RESUMO

Retinoic acid (RA) signaling plays a key role in the development and function of several systems in mammals. We previously discovered that the de novo mutations c.1159C>T (p.Arg387Cys) and c.1159C>A (p.Arg387Ser) in the RA Receptor Beta (RARB) gene cause microphthalmia and diaphragmatic hernia. However, the natural history of affected subjects beyond the prenatal or neonatal period was unknown. Here, we describe nine additional subjects with microphthalmia who have de novo mutations in RARB, including the previously described p.Arg387Cys as well as the novel c.887G>C (p.Gly296Ala) and c.638T>C (p.Leu213Pro). Moreover, we review the information on four previously reported cases. All subjects who survived the neonatal period (n = 10) displayed severe global developmental delay with progressive motor impairment due to spasticity and/or dystonia (with or without chorea). The majority of subjects also showed Chiari type I malformation and severe feeding difficulties. We previously found that p.Arg387Cys and p.Arg387Ser induce a gain-of-function. We show here that the p.Gly296Ala and p.Leu213Pro RARB mutations further promote the RA ligand-induced transcriptional activity by twofold to threefold over the wild-type receptor, also indicating a gain-of-function mechanism. These observations suggest that precise regulation of RA signaling is required for brain development and/or function in humans.


Assuntos
Mutação com Ganho de Função , Deficiência Intelectual/genética , Transtornos dos Movimentos/genética , Receptores do Ácido Retinoico/genética , Adolescente , Criança , Pré-Escolar , Distúrbios Distônicos , Feminino , Humanos , Recém-Nascido , Masculino , Modelos Moleculares , Mutação de Sentido Incorreto , Conformação Proteica , Receptores do Ácido Retinoico/química , Ativação Transcricional
8.
Mol Autism ; 6: 19, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25844147

RESUMO

BACKGROUND: Apparently balanced chromosomal rearrangements can be associated with an abnormal phenotype, including intellectual disability and autism spectrum disorder (ASD). Genome-wide microarrays reveal cryptic genomic imbalances, related or not to the breakpoints, in 25% to 50% of patients with an abnormal phenotype carrying a microscopically balanced chromosomal rearrangement. Here we performed microarray analysis of 18 patients with ASD carrying balanced chromosomal abnormalities to identify submicroscopic imbalances implicated in abnormal neurodevelopment. METHODS: Eighteen patients with ASD carrying apparently balanced chromosomal abnormalities were screened using single nucleotide polymorphism (SNP) arrays. Nine rearrangements were de novo, seven inherited, and two of unknown inheritance. Genomic imbalances were confirmed by fluorescence in situ hybridization and quantitative PCR. RESULTS: We detected clinically significant de novo copy number variants in four patients (22%), including three with de novo rearrangements and one with an inherited abnormality. The sizes ranged from 3.3 to 4.9 Mb; three were related to the breakpoint regions and one occurred elsewhere. We report a patient with a duplication of the Wolf-Hirschhorn syndrome critical region, contributing to the delineation of this rare genomic disorder. The patient has a chromosome 4p inverted duplication deletion, with a 0.5 Mb deletion of terminal 4p and a 4.2 Mb duplication of 4p16.2p16.3. The other cases included an apparently balanced de novo translocation t(5;18)(q12;p11.2) with a 4.2 Mb deletion at the 18p breakpoint, a subject with de novo pericentric inversion inv(11)(p14q23.2) in whom the array revealed a de novo 4.9 Mb deletion in 7q21.3q22.1, and a patient with a maternal inv(2)(q14.2q37.3) with a de novo 3.3 Mb terminal 2q deletion and a 4.2 Mb duplication at the proximal breakpoint. In addition, we identified a rare de novo deletion of unknown significance on a chromosome unrelated to the initial rearrangement, disrupting a single gene, RFX3. CONCLUSIONS: These findings underscore the utility of SNP arrays for investigating apparently balanced chromosomal abnormalities in subjects with ASD or related neurodevelopmental disorders in both clinical and research settings.

9.
Neurology ; 82(22): 1999-2002, 2014 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-24808016

RESUMO

OBJECTIVE: We screened a large series of individuals with congenital mirror movements (CMM) for mutations in the 2 identified causative genes, DCC and RAD51. METHODS: We studied 6 familial and 20 simplex CMM cases. Each patient had a standardized neurologic assessment. Analysis of DCC and RAD51 coding regions included Sanger sequencing and a quantitative method allowing detection of micro rearrangements. We then compared the frequency of rare variants predicted to be pathogenic by either the PolyPhen-2 or the SIFT algorithm in our population and in the 4,300 controls of European origin on the Exome Variant Server. RESULTS: We found 3 novel truncating mutations of DCC that segregate with CMM in 4 of the 6 families. Among the 20 simplex cases, we found one exonic deletion of DCC, one DCC mutation leading to a frameshift, 5 missense variants in DCC, and 2 missense variants in RAD51. All 7 missense variants were predicted to be pathogenic by one or both algorithms. Statistical analysis showed that the frequency of variants predicted to be deleterious was significantly different between patients and controls (p < 0.001 for both RAD51 and DCC). CONCLUSION: Mutations and variants in DCC and RAD51 are strongly associated with CMM, but additional genes causing CMM remain to be discovered.


Assuntos
Proteínas de Transporte/genética , Transtornos dos Movimentos/genética , Mutação/genética , Receptores de Superfície Celular/genética , Proteínas Supressoras de Tumor/genética , Códon sem Sentido , Receptor DCC , Análise Mutacional de DNA , Humanos , Mutação de Sentido Incorreto , Linhagem , Índice de Gravidade de Doença
10.
Am J Hum Genet ; 94(5): 734-44, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24726473

RESUMO

Gordon syndrome (GS), or distal arthrogryposis type 3, is a rare, autosomal-dominant disorder characterized by cleft palate and congenital contractures of the hands and feet. Exome sequencing of five GS-affected families identified mutations in piezo-type mechanosensitive ion channel component 2 (PIEZO2) in each family. Sanger sequencing revealed PIEZO2 mutations in five of seven additional families studied (for a total of 10/12 [83%] individuals), and nine families had an identical c.8057G>A (p.Arg2686His) mutation. The phenotype of GS overlaps with distal arthrogryposis type 5 (DA5) and Marden-Walker syndrome (MWS). Using molecular inversion probes for targeted sequencing to screen PIEZO2, we found mutations in 24/29 (82%) DA5-affected families and one of two MWS-affected families. The presence of cleft palate was significantly associated with c.8057G>A (Fisher's exact test, adjusted p value < 0.0001). Collectively, although GS, DA5, and MWS have traditionally been considered separate disorders, our findings indicate that they are etiologically related and perhaps represent variable expressivity of the same condition.


Assuntos
Anormalidades Múltiplas/genética , Aracnodactilia/genética , Artrogripose/genética , Blefarofimose/genética , Fissura Palatina/genética , Pé Torto Equinovaro/genética , Doenças do Tecido Conjuntivo/genética , Contratura/genética , Deformidades Congênitas da Mão/genética , Canais Iônicos/genética , Oftalmoplegia/genética , Doenças Retinianas/genética , Anormalidades Múltiplas/patologia , Aracnodactilia/patologia , Artrogripose/patologia , Blefarofimose/patologia , Criança , Pré-Escolar , Fissura Palatina/patologia , Pé Torto Equinovaro/patologia , Doenças do Tecido Conjuntivo/patologia , Contratura/patologia , Exoma/genética , Feminino , Deformidades Congênitas da Mão/patologia , Humanos , Masculino , Mutação , Oftalmoplegia/patologia , Linhagem , Doenças Retinianas/patologia
11.
Am J Hum Genet ; 93(4): 765-72, 2013 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-24075189

RESUMO

Anophthalmia and/or microphthalmia, pulmonary hypoplasia, diaphragmatic hernia, and cardiac defects are the main features of PDAC syndrome. Recessive mutations in STRA6, encoding a membrane receptor for the retinol-binding protein, have been identified in some cases with PDAC syndrome, although many cases have remained unexplained. Using whole-exome sequencing, we found that two PDAC-syndrome-affected siblings, but not their unaffected sibling, were compound heterozygous for nonsense (c.355C>T [p.Arg119(∗)]) and frameshift (c.1201_1202insCT [p.Ile403Serfs(∗)15]) mutations in retinoic acid receptor beta (RARB). Transfection studies showed that p.Arg119(∗) and p.Ile403Serfs(∗)15 altered RARB had no transcriptional activity in response to ligands, confirming that the mutations induced a loss of function. We then sequenced RARB in 15 subjects with anophthalmia and/or microphthalmia and at least one other feature of PDAC syndrome. Surprisingly, three unrelated subjects with microphthalmia and diaphragmatic hernia showed de novo missense mutations affecting the same codon; two of the subjects had the c.1159C>T (Arg387Cys) mutation, whereas the other one carried the c.1159C>A (p.Arg387Ser) mutation. We found that compared to the wild-type receptor, p.Arg387Ser and p.Arg387Cys altered RARB induced a 2- to 3-fold increase in transcriptional activity in response to retinoic acid ligands, suggesting a gain-of-function mechanism. Our study thus suggests that both recessive and dominant mutations in RARB cause anophthalmia and/or microphthalmia and diaphragmatic hernia, providing further evidence of the crucial role of the retinoic acid pathway during eye development and organogenesis.


Assuntos
Hérnia Diafragmática/genética , Microftalmia/genética , Mutação , Receptores do Ácido Retinoico/genética , Adolescente , Anoftalmia/genética , Anoftalmia/metabolismo , Exoma , Feminino , Hérnia Diafragmática/metabolismo , Humanos , Recém-Nascido , Masculino , Microftalmia/metabolismo , Receptores do Ácido Retinoico/metabolismo , Proteínas de Ligação ao Retinol/genética , Proteínas de Ligação ao Retinol/metabolismo , Tretinoína/metabolismo
12.
Am J Hum Genet ; 93(1): 141-9, 2013 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-23810378

RESUMO

Short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger anomaly, and teething delay (SHORT) syndrome is a developmental disorder with an unknown genetic cause and hallmarks that include insulin resistance and lack of subcutaneous fat. We ascertained two unrelated individuals with SHORT syndrome, hypothesized that the observed phenotype was most likely due to de novo mutations in the same gene, and performed whole-exome sequencing in the two probands and their unaffected parents. We then confirmed our initial observations in four other subjects with SHORT syndrome from three families, as well as 14 unrelated subjects presenting with syndromic insulin resistance and/or generalized lipoatrophy associated with dysmorphic features and growth retardation. Overall, we identified in nine affected individuals from eight families de novo or inherited PIK3R1 mutations, including a mutational hotspot (c.1945C>T [p.Arg649Trp]) present in four families. PIK3R1 encodes the p85α, p55α, and p50α regulatory subunits of class IA phosphatidylinositol 3 kinases (PI3Ks), which are known to play a key role in insulin signaling. Functional data from fibroblasts derived from individuals with PIK3R1 mutations showed severe insulin resistance for both proximal and distal PI3K-dependent signaling. Our findings extend the genetic causes of severe insulin-resistance syndromes and provide important information with respect to the function of PIK3R1 in normal development and its role in human diseases, including growth delay, Rieger anomaly and other ocular affections, insulin resistance, diabetes, paucity of fat, and ovarian cysts.


Assuntos
Transtornos do Crescimento/genética , Hipercalcemia/genética , Resistência à Insulina/genética , Doenças Metabólicas/genética , Nefrocalcinose/genética , Fosfatidilinositol 3-Quinases/metabolismo , Análise Mutacional de DNA , Exoma , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Predisposição Genética para Doença , Idade Gestacional , Glucose/metabolismo , Glucose/farmacologia , Humanos , Insulina/metabolismo , Insulina/farmacologia , Masculino , Mutação , Linhagem , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais
13.
Am J Med Genet A ; 158A(10): 2430-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22903608

RESUMO

FOXC1 deletion, duplication, and mutations are associated with Axenfeld-Rieger anomaly, and Dandy-Walker malformation spectrum. We describe the clinical history, physical findings, and available brain imaging studies in three fetuses, two children, and one adult with 6p25 deletions encompassing FOXC1. Various combinations of ocular and cerebellar malformations were found. In all three fetuses, necropsy including detailed microscopic assessments of the eyes and brains showed ocular anterior segment dysgenesis suggestive of Axenfeld-Rieger anomaly. Five 6p25 deletions were terminal, including two derived from inherited reciprocal translocations; the remaining 6p25 deletion was interstitial. The size and breakpoints of these deletions were characterized using comparative genomic hybridization arrays. All six deletions included FOXC1. Our data confirm that FOXC1 haploinsufficiency plays a major role in the phenotype of patients with 6p25 deletions. Histopathological features of Axenfeld-Rieger anomaly were clearly identifiable before the beginning of the third-trimester of gestation.


Assuntos
Doenças Cerebelares/patologia , Cromossomos Humanos Par 6/genética , Anormalidades do Olho/patologia , Feto/patologia , Fatores de Transcrição Forkhead/genética , Deleção de Genes , Adulto , Segmento Anterior do Olho/anormalidades , Segmento Anterior do Olho/patologia , Doenças Cerebelares/genética , Pré-Escolar , Hibridização Genômica Comparativa , Síndrome de Dandy-Walker/genética , Síndrome de Dandy-Walker/patologia , Anormalidades do Olho/genética , Oftalmopatias Hereditárias , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Fenótipo , Gravidez
14.
Eur J Hum Genet ; 20(5): 527-33, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22234157

RESUMO

In 65 patients, who had unexplained ocular developmental anomalies (ODAs) with at least one other birth defect and/or intellectual disability, we performed oligonucleotide comparative genome hybridisation-based microarray analysis (array-CGH; 105A or 180K, Agilent Technologies). In four patients, array-CGH identified clinically relevant deletions encompassing a gene known to be involved in ocular development (FOXC1 or OTX2). In four other patients, we found three pathogenic deletions not classically associated with abnormal ocular morphogenesis, namely, del(17)(p13.3p13.3), del(10)(p14p15.3), and del(16)(p11.2p11.2). We also detected copy number variations of uncertain pathogenicity in two other patients. Rearranged segments ranged in size from 0.04 to 5.68 Mb. These results show that array-CGH provides a high diagnostic yield (15%) in patients with syndromal ODAs and can identify previously unknown chromosomal regions associated with these conditions. In addition to their importance for diagnosis and genetic counselling, these data may help identify genes involved in ocular development.


Assuntos
Anormalidades do Olho/genética , Genoma Humano , Adolescente , Adulto , Criança , Aberrações Cromossômicas , Hibridização Genômica Comparativa , Feminino , Fatores de Transcrição Forkhead/genética , Dosagem de Genes , Humanos , Masculino , Fatores de Transcrição Otx/genética , Síndrome
15.
Ophthalmic Genet ; 33(1): 39-43, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21834622

RESUMO

INTRODUCTION: Macular dystrophy is a cause of childhood and adult visual handicap and has been associated with multiple gene defects. Syndromic macular dystrophy is rare and a novel congenital form of syndromic macular dystrophy is presented. The authors report on a consanguineous family in which the 5-year-old female proband presented with nystagmus and low vision due to congenital macular dystrophy visible on fundus examination associated with complete corpus callosum agenesis, hippocampi hypoplasia and recurrent illnesses. MATERIALS AND METHODS: Patients signed informed consent forms to participate in the research. Proband was screened for 18 recessive macular dystrophy genes and ABCA4 and had a G banded karyotype on peripheral blood lymphocytes. Patients were evaluated using ocular biomicrosopy, fluorescein retinal angiograms, electroretinograms, visual evoked potentials, retinal optical coherence tomography, brain MRI and multifocal electroretinograms. RESULTS: The older brother presented with subclinical findings of bilateral absence of foveal macular peak on multifocal electroretinograms and minimal corpus callosum hypoplasia. The younger sister was recently discovered to have a similar macular dystrophy. The father showed subclinical unilateral decreased foveal macular peak and the mother showed a granular-appearing fundus. No mutations were identified in the RP and macular dystrophy genes screened. DISCUSSION: A review of the literature confirms that this is the first report of a congenital and possibly developmental macular dystrophy, with neurologic syndromic features and possible autosomal recessive inheritance but varying penetrance.


Assuntos
Agenesia do Corpo Caloso/genética , Hipocampo/anormalidades , Degeneração Macular/congênito , Criança , Pré-Escolar , Consanguinidade , Eletrorretinografia , Feminino , Angiofluoresceinografia , Humanos , Cariotipagem , Imagem por Ressonância Magnética , Masculino , Nistagmo Congênito/genética , Linhagem , Tomografia de Coerência Óptica , Baixa Visão/genética
16.
Eur J Med Genet ; 54(2): 157-60, 2011 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21044901

RESUMO

Hydrometrocolpos and polydactyly diagnosed in the prenatal period or early childhood may raise diagnostic dilemmas especially in distinguishing McKusick-Kaufman syndrome (MKKS) and the Bardet-Biedl syndrome (BBS). These two conditions can initially overlap. With time, the additional features of BBS appearing in childhood, such as retinitis pigmentosa, obesity, learning disabilities and progressive renal dysfunction allow clear differentiation between BBS and MKKS. Genotype overlap also exists, as mutations in the MKKS-BBS6 gene are found in both syndromes. We report 7 patients diagnosed in the neonatal period with hydrometrocolpos and polydactyly who carry mutations in various BBS genes (BBS6, BBS2, BBS10, BBS8 and BBS12), stressing the importance of wide BBS genotyping in patients with this clinical association for diagnosis, prognosis and genetic counselling.


Assuntos
Síndrome de Bardet-Biedl/diagnóstico , Heterogeneidade Genética , Técnicas de Diagnóstico Molecular/métodos , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Síndrome de Bardet-Biedl/genética , Diagnóstico Diferencial , Genótipo , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/genética , Humanos , Hidrocolpos/diagnóstico , Hidrocolpos/genética , Recém-Nascido , Mutação , Fenótipo , Polidactilia/diagnóstico , Polidactilia/genética , Doenças Uterinas/diagnóstico , Doenças Uterinas/genética
17.
Mol Vis ; 16: 1705-11, 2010 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-20806047

RESUMO

PURPOSE: Aniridia and congenital cataract represent rare but severe developmental ocular conditions. We examined 33 probands from France for mutations in several transcription factors associated with these phenotypes, the forkhead box E3 (FOXE3), paired box gene 6 (PAX6), paired-like homeodomain transcription factor 2 (PITX2), and paired-like homeodomain transcription factor 3 (PITX3) genes. METHODS: Out of 33 probands, 27 were affected with congenital cataract while the remaining six were affected with aniridia (with or without cataract). The coding regions of FOXE3, PAX6, PITX2, and PITX3 were examined by direct DNA sequencing of gene-specific PCR products. RESULTS: A novel dominant mutation at the stop codon of FOXE3, c.959G>C (p.X320SerextX72), was identified in a patient with congenital cataract. Another novel FOXE3 sequence change, c.571-579dup (p.Tyr191_Pro193dup), was identified in a patient with aniridia, mild lens opacities, and some additional ocular defects; this patient was also found to carry a nonsense mutation in PAX6. PAX6 mutations were identified in two additional probands with aniridia and cataracts. None of the observed sequence alterations were found in normal controls. No mutations were identified in PITX2 or PITX3. CONCLUSIONS: The p.X320SerextX72 mutation is only the fourth FOXE3 allele associated with a dominant phenotype since the majority of FOXE3 mutations appear to be recessive with no phenotype observed in heterozygous carriers. The encoded protein is predicted to contain a complete normal sequence followed by seventy-two erroneous amino acids; the position and effect of this mutation are similar to two of the previously reported dominant changes, suggesting a common mechanism for dominant alleles. The p.Tyr191_Pro193dup is predicted to result in an in-frame duplication of three amino acids; however, the contribution of this mutation to the phenotype is unclear since the affected patient also carries a nonsense mutation in PAX6 which acts upstream of FOXE3 in the molecular pathway. The identified PAX6 mutations correspond to the two most commonly observed mutant alleles and demonstrate phenotypes that are consistent with the previously reported spectrum.


Assuntos
Aniridia/complicações , Aniridia/genética , Catarata/congênito , Proteínas do Olho/genética , Fatores de Transcrição Forkhead/genética , Genes Dominantes/genética , Proteínas de Homeodomínio/genética , Mutação/genética , Fatores de Transcrição Box Pareados/genética , Proteínas Repressoras/genética , Sequência de Aminoácidos , Sequência de Bases , Catarata/complicações , Catarata/genética , Análise Mutacional de DNA , Proteínas do Olho/química , Fatores de Transcrição Forkhead/química , Proteínas de Homeodomínio/química , Humanos , Dados de Sequência Molecular , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/química , Proteínas Repressoras/química , Alinhamento de Sequência
18.
Am J Hum Genet ; 85(5): 706-10, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19853239

RESUMO

Desbuquois dysplasia is a severe condition characterized by short stature, joint laxity, scoliosis, and advanced carpal ossification with a delta phalanx. Studying nine Desbuquois families, we identified seven distinct mutations in the Calcium-Activated Nucleotidase 1 gene (CANT1), which encodes a soluble UDP-preferring nucleotidase belonging to the apyrase family. Among the seven mutations, four were nonsense mutations (Del 5' UTR and exon 1, p.P245RfsX3, p.S303AfsX20, and p.W125X), and three were missense mutations (p.R300C, p.R300H, and p.P299L) responsible for the change of conserved amino acids located in the seventh nucleotidase conserved region (NRC). The arginine substitution at position 300 was identified in five out of nine families. The specific function of CANT1 is as yet unknown, but its substrates are involved in several major signaling functions, including Ca2+ release, through activation of pyrimidinergic signaling. Importantly, using RT-PCR analysis, we observed a specific expression in chondrocytes. We also found electron-dense material within distended rough endoplasmic reticulum in the fibroblasts of Desbuquois patients. Our findings demonstrate the specific involvement of a nucleotidase in the endochondral ossification process.


Assuntos
Doenças do Desenvolvimento Ósseo/genética , Cálcio/metabolismo , Mutação , Nucleotidases/genética , Regiões 5' não Traduzidas , Adolescente , Adulto , Sequência de Aminoácidos , Substituição de Aminoácidos , Arginina/metabolismo , Doenças do Desenvolvimento Ósseo/diagnóstico por imagem , Células Cultivadas , Pré-Escolar , Condrócitos/metabolismo , Cromossomos Humanos Par 17 , Códon sem Sentido , Consanguinidade , Retículo Endoplasmático Rugoso/ultraestrutura , Éxons , Evolução Fatal , Feminino , Fibroblastos/ultraestrutura , Homozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Núcleo Familiar , RNA Mensageiro/metabolismo , Radiografia
19.
Eur J Hum Genet ; 17(10): 1325-35, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19367324

RESUMO

Oculofaciocardiodental (OFCD) and Lenz microphthalmia syndromes form part of a spectrum of X-linked microphthalmia disorders characterized by ocular, dental, cardiac and skeletal anomalies and mental retardation. The two syndromes are allelic, caused by mutations in the BCL-6 corepressor gene (BCOR). To extend the series of phenotypes associated with pathogenic mutations in BCOR, we sequenced the BCOR gene in patients with (1) OFCD syndrome, (2) putative X-linked ('Lenz') microphthalmia syndrome, (3) isolated ocular defects and (4) laterality phenotypes. We present a new cohort of females with OFCD syndrome and null mutations in BCOR, supporting the hypothesis that BCOR is the sole molecular cause of this syndrome. We identify for the first time mosaic BCOR mutations in two females with OFCD syndrome and one apparently asymptomatic female. We present a female diagnosed with isolated ocular defects and identify minor features of OFCD syndrome, suggesting that OFCD syndrome may be mild and underdiagnosed. We have sequenced a cohort of males diagnosed with putative X-linked microphthalmia and found a mutation, p.P85L, in a single case, suggesting that BCOR mutations are not a major cause of X-linked microphthalmia in males. The absence of BCOR mutations in a panel of patients with non-specific laterality defects suggests that mutations in BCOR are not a major cause of isolated heart and laterality defects. Phenotypic analysis of OFCD and Lenz microphthalmia syndromes shows that in addition to the standard diagnostic criteria of congenital cataract, microphthalmia and radiculomegaly, patients should be examined for skeletal defects, particularly radioulnar synostosis, and cardiac/laterality defects.


Assuntos
Anormalidades do Olho/genética , Cardiopatias/genética , Deficiência Intelectual/genética , Microftalmia/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Adolescente , Adulto , Idoso , Alelos , Animais , Criança , Pré-Escolar , Estudos de Coortes , Anormalidades do Olho/complicações , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/complicações , Doenças Genéticas Ligadas ao Cromossomo X/genética , Cardiopatias/complicações , Humanos , Recém-Nascido , Deficiência Intelectual/complicações , Masculino , Microftalmia/complicações , Pessoa de Meia-Idade , Síndrome
20.
Am J Med Genet A ; 143A(12): 1268-81, 2007 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-17506106

RESUMO

The combination of pulmonary agenesis/dysgenesis/hypoplasia, microphthalmia/anophthalmia, and a diaphragmatic defect (agenesis or eventration) is a rare syndrome presumed to have an autosomal recessive mode of inheritance based on a report of affected siblings born to unaffected parents [Seller et al., 1996]. The condition is known as Spear syndrome and Matthew-Wood syndrome, although genetic heterogeneity cannot be ruled out. We report on eight patients with this condition including a living child, three sibs and three isolated cases. Most presented with fetal ultrasound findings of microphthalmia/anophthalmia, and diaphragmatic eventration/hernia and in five, cardiac abnormalities were also found. The earliest detection was at 20 weeks gestation. This is the second report of sibs affected with this condition, which supports an autosomal recessive mode of inheritance. We present the first and only reported living patient with this condition and expand the intrafamilial, interfamilial, and ethnic variability of this condition. We suggest changing the condition's name to PDAC to reflect the most important components of this condition.


Assuntos
Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Anoftalmia/patologia , Diafragma/anormalidades , Cardiopatias Congênitas , Pulmão/anormalidades , Anoftalmia/genética , Feminino , Genes Recessivos , Humanos , Recém-Nascido , Masculino
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