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1.
Neuro Oncol ; 2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31504825

RESUMO

BACKGROUND: Medulloblastomas may occur in a predisposition context, including familial adenomatosis polyposis. Medulloblastomas related to APC germline pathogenic variant remain rare and poorly described. Their similarities with sporadic WNT medulloblastomas still require to be described. METHODS: We performed a multicentric retrospective review of 12 patients treated between 1988 and 2018 for medulloblastoma with identified or highly suspected (personal of familial history) APC germline pathogenic variant. We report personal and familial history, APC gene pathogenic variant whenever available, clinical and histological characteristics of the medulloblastoma, treatments, and long-term outcome including second tumor and late sequelae. RESULTS: Medulloblastomas associated with APC pathogenic variant are mainly classic (11/11 patients, 1 NA), non-metastatic (10/12 patients) medulloblastomas, with nuclear immunoreactivity for ß-catenin (9/9 tested cases). 10/11 assessable patients are disease-free with a median follow-up of 10.7 years [1-28]. Secondary tumors included desmoid tumors in 7 patients (9 tumors), 1 thyroid carcinoma, 2 pilomatricomas, 1 osteoma, 1 vertebral hemangioma, and 1 malignant Triton in the radiation field which caused the only cancer-related death in our series. CONCLUSIONS: Medulloblastomas associated with APC pathogenic variant have an overall favorable outcome, even for metastatic tumors. Yet, long-term survival is clouded by second tumor occurrence; treatment may play some role in some of these second malignancies. Our findings raise the question of applying de-escalation therapeutic protocol to treat patients with APC germline pathogenic variant given the excellent outcome, and reduced intensity of craniospinal irradiation may be further evaluated.

2.
Hum Mutat ; 40(10): 1713-1730, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31050087

RESUMO

Ataxia-telangiectasia (A-T) is a recessive disorder caused by biallelic pathogenic variants of ataxia-telangiectasia mutated (ATM). This disease is characterized by progressive ataxia, telangiectasia, immune deficiency, predisposition to malignancies, and radiosensitivity. However, hypomorphic variants may be discovered associated with very atypical phenotypes, raising the importance of evaluating their pathogenic effects. In this study, multiple functional analyses were performed on lymphoblastoid cell lines from 36 patients, comprising 49 ATM variants, 24 being of uncertain significance. Thirteen patients with atypical phenotype and presumably hypomorphic variants were of particular interest to test strength of functional analyses and to highlight discrepancies with typical patients. Western-blot combined with transcript analyses allowed the identification of one missing variant, confirmed suspected splice defects and revealed unsuspected minor transcripts. Subcellular localization analyses confirmed the low level and abnormal cytoplasmic localization of ATM for most A-T cell lines. Interestingly, atypical patients had lower kinase defect and less altered cell-cycle distribution after genotoxic stress than typical patients. In conclusion, this study demonstrated the pathogenic effects of the 49 variants, highlighted the strength of KAP1 phosphorylation test for pathogenicity assessment and allowed the establishment of the Ataxia-TeLangiectasia Atypical Score to predict atypical phenotype. Altogether, we propose strategies for ATM variant detection and classification.

3.
Prenat Diagn ; 39(6): 464-470, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30896039

RESUMO

OBJECTIVES: Congenital heart defects (CHDs) may be isolated or associated with other malformations. The use of chromosome microarray (CMA) can increase the genetic diagnostic yield for CHDs by between 4% and 10%. The objective of this study was to evaluate the value of CMA after the prenatal diagnosis of an isolated CHD. METHODS: In a retrospective, nationwide study performed in France, we collected data on all cases of isolated CHD that had been explored using CMAs in 2015. RESULTS: A total of 239 fetuses were included and 33 copy number variations (CNVs) were reported; 19 were considered to be pathogenic, six were variants of unknown significance, and eight were benign variants. The anomaly detection rate was 10.4% overall but ranged from 0% to 16.7% as a function of the isolated CHD in question. The known CNVs were 22q11.21 deletions (n = 10), 22q11.21 duplications (n = 2), 8p23 deletions (n = 2), an Alagille syndrome (n = 1), and a Kleefstra syndrome (n = 1). CONCLUSION: The additional diagnostic yield was clinically significant (3.1%), even when anomalies in the 22q11.21 region were not taken into account. Hence, patients with a suspected isolated CHD and a normal karyotype must be screened for chromosome anomalies other than 22q11.21 duplications and deletions.

4.
Dis Colon Rectum ; 62(4): 470-475, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30640315

RESUMO

BACKGROUND: Almost no prospective data on endoscopy in MUTYH monoallelic carriers are available. OBJECTIVE: This study aimed to define the prevalence of colorectal and duodenal adenomas in a population of people presenting with a single mutation of the MUTYH gene and being first-degree relatives of biallelic MUTYH mutation carriers. DESIGN: This study is a prospective cohort evaluation. PATIENTS: Patients were first-degree relatives of a patient who had polyposis with biallelic MUTYH mutation and carrying a single gene mutation of the gene from 12 French centers. SETTINGS: This is a multicenter study. INTERVENTION: Detailed data on life habits (tobacco, alcohol, and nonsteroidal anti-inflammatory drugs), extraintestinal manifestations, and germline analysis were recorded. Complete endoscopic evaluation (colonoscopy and upper endoscopy) with chromoendoscopy was performed. RESULTS: Sixty-two patients were prospectively included (34 women (55%), mean age of 54, range 30-70 years). Thirty-two patients (52%) presented with colorectal polyps at colonoscopy. Of these patients with polyps, 15 (25%) had only adenomas, 8 (13%) had only hyperplastic polyps, 1 (1%) had sessile serrated adenomas, and 8 (13%) had adenomas and/or sessile serrated adenomas. We detected, in total, 29 adenomas with low-grade dysplasia, 5 adenomas with high-grade dysplasia, and 6 sessile serrated adenomas. Fourteen patients (23%) presented with a single adenoma, and 10 (16%) had 1 to 5 adenomas. No patient had more than 5 adenomas. At upper endoscopy, 3 had a limited number of fundic gland polyps; none had duodenal adenomas. The 2 main missense mutations c.1145G>A, p.Gly382Asp and c.494A>G, p.Tyr165Cys were associated with the development of colorectal adenomas/serrated polyps in these monoallelic carriers. LIMITATIONS: This study was limited by the small number of patients. CONCLUSIONS: This prospective study provides unique prospective data suggesting that monoallelic mutation carriers related to patients with polyposis show no colorectal polyposis and have very limited upper GI manifestations justifying an endoscopic follow-up. See Video Abstract at http://links.lww.com/DCR/A862.


Assuntos
Adenoma , Polipose Adenomatosa do Colo , Neoplasias Colorretais , DNA Glicosilases/genética , Neoplasias Duodenais , Endoscopia do Sistema Digestório/métodos , Adenoma/genética , Adenoma/patologia , Polipose Adenomatosa do Colo/diagnóstico , Polipose Adenomatosa do Colo/epidemiologia , Polipose Adenomatosa do Colo/genética , Adulto , Idoso , Estudos de Coortes , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Corantes/farmacologia , Neoplasias Duodenais/genética , Neoplasias Duodenais/patologia , Saúde da Família , Feminino , França/epidemiologia , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Mutação , Avaliação de Resultados (Cuidados de Saúde) , Estudos Prospectivos
5.
J Med Genet ; 55(6): 359-371, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29618507

RESUMO

The Xq28 duplication involving the MECP2 gene (MECP2 duplication) has been mainly described in male patients with severe developmental delay (DD) associated with spasticity, stereotypic movements and recurrent infections. Nevertheless, only a few series have been published. We aimed to better describe the phenotype of this condition, with a focus on morphological and neurological features. Through a national collaborative study, we report a large French series of 59 affected males with interstitial MECP2 duplication. Most of the patients (93%) shared similar facial features, which evolved with age (midface hypoplasia, narrow and prominent nasal bridge, thick lower lip, large prominent ears), thick hair, livedo of the limbs, tapered fingers, small feet and vasomotor troubles. Early hypotonia and global DD were constant, with 21% of patients unable to walk. In patients able to stand, lower limbs weakness and spasticity led to a singular standing habitus: flexion of the knees, broad-based stance with pseudo-ataxic gait. Scoliosis was frequent (53%), such as divergent strabismus (76%) and hypermetropia (54%), stereotypic movements (89%), without obvious social withdrawal and decreased pain sensitivity (78%). Most of the patients did not develop expressive language, 35% saying few words. Epilepsy was frequent (59%), with a mean onset around 7.4 years of age, and often (62%) drug-resistant. Other medical issues were frequent: constipation (78%), and recurrent infections (89%), mainly lung. We delineate the clinical phenotype of MECP2 duplication syndrome in a large series of 59 males. Pulmonary hypertension appeared as a cause of early death in these patients, advocating its screening early in life.

6.
Hum Mutat ; 37(12): 1329-1339, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27363716

RESUMO

Holoprosencephaly (HPE) is the most common congenital cerebral malformation in humans, characterized by impaired forebrain cleavage and midline facial anomalies. It presents a high heterogeneity, both in clinics and genetics. We have developed a novel targeted next-generation sequencing (NGS) assay and screened a cohort of 257 HPE patients. Mutations with high confidence in their deleterious effect were identified in approximately 24% of the cases and were held for diagnosis, whereas variants of uncertain significance were identified in 10% of cases. This study provides a new classification of genes that are involved in HPE. SHH, ZIC2, and SIX3 remain the top genes in term of frequency with GLI2, and are followed by FGF8 and FGFR1. The three minor HPE genes identified by our study are DLL1, DISP1, and SUFU. Here, we demonstrate that fibroblast growth factor signaling must now be considered a major pathway involved in HPE. Interestingly, several cases of double mutations were found and argue for a polygenic inheritance of HPE. Altogether, it supports that the implementation of NGS in HPE diagnosis is required to improve genetic counseling.


Assuntos
Fatores de Crescimento de Fibroblastos/genética , Holoprosencefalia/genética , Mutação , Feminino , Predisposição Genética para Doença , Proteínas Hedgehog/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos , Análise de Sequência de DNA/métodos , Transdução de Sinais
7.
Eur J Obstet Gynecol Reprod Biol ; 203: 116-20, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27280540

RESUMO

OBJECTIVE: Evaluate accuracy of prenatal ultrasound findings in predicting the risk of bowel atresia in patients with gastroschisis. METHODS: A retrospective study was conducted on 18 fetuses with a prenatal diagnostic of gastroschisis treated at University hospital of Saint Etienne France between 2002 and 2012. Ultrasound abnormalities were used to classify them into three groups: no ultrasound abnormality (n=4), oligohydramnios (n=9), intra-abdominal bowel dilatation ≥20.5mm (n=5). Postnatal outcomes were compared between groups. The threshold value of 20.5mm for the prediction of atresia was determined through the receiver operator characteristics curve. RESULTS: In the group with oligohydramnios, intra uterine growth restriction were significantly more frequent (p=0.015) and three newborns had serositis including two with secondary complications after the initial surgery. In the group with major intra-abdominal bowel dilatation, all had a narrow defect <10mm significantly more than other fetuses (p=0.002). Intra-abdominal bowel dilatation reaching 20.5mm started at a mean gestational age significantly lower than that of the other fetuses (23.3 versus 29.7 weeks p=0.02). On the five fetuses presented intra-abdominal bowel dilatation ≥20.5mm, four showed atresia and no other newborn has this complication (p=0.0016). The threshold value of 20.5mm has a sensitivity of 100% and a specificity of 92.9%. The area under the curve was equal to 96.4%. CONCLUSION: Intra-abdominal bowel dilatation ≥20.5mm seems to be associated with the risk of postnatal atresia. MRI could help to clarify a complicated or uncertain ultrasound aspect.


Assuntos
Anormalidades Múltiplas/diagnóstico por imagem , Retardo do Crescimento Fetal/diagnóstico por imagem , Gastrosquise/diagnóstico por imagem , Atresia Intestinal/diagnóstico por imagem , Ultrassonografia Pré-Natal , Abdome/diagnóstico por imagem , Abdome/embriologia , Abdome/cirurgia , Anormalidades Múltiplas/embriologia , Anormalidades Múltiplas/epidemiologia , Anormalidades Múltiplas/cirurgia , Adulto , Comorbidade , Dilatação Patológica/diagnóstico por imagem , Dilatação Patológica/embriologia , Dilatação Patológica/epidemiologia , Dilatação Patológica/cirurgia , Feminino , Retardo do Crescimento Fetal/epidemiologia , França/epidemiologia , Gastrosquise/embriologia , Gastrosquise/cirurgia , Hospitais Universitários , Humanos , Recém-Nascido , Atresia Intestinal/embriologia , Atresia Intestinal/epidemiologia , Atresia Intestinal/cirurgia , Masculino , Oligo-Hidrâmnio/diagnóstico por imagem , Oligo-Hidrâmnio/epidemiologia , Gravidez , Estudos Retrospectivos , Risco , Sensibilidade e Especificidade , Serosite/diagnóstico por imagem , Serosite/embriologia , Serosite/epidemiologia , Serosite/cirurgia
8.
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
9.
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
10.
Am J Hum Genet ; 98(3): 541-552, 2016 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-26942287

RESUMO

Intellectual disability (ID) and autism spectrum disorders (ASD) are genetically heterogeneous, and a significant number of genes have been associated with both conditions. A few mutations in POGZ have been reported in recent exome studies; however, these studies do not provide detailed clinical information. We collected the clinical and molecular data of 25 individuals with disruptive mutations in POGZ by diagnostic whole-exome, whole-genome, or targeted sequencing of 5,223 individuals with neurodevelopmental disorders (ID primarily) or by targeted resequencing of this locus in 12,041 individuals with ASD and/or ID. The rarity of disruptive mutations among unaffected individuals (2/49,401) highlights the significance (p = 4.19 × 10(-13); odds ratio = 35.8) and penetrance (65.9%) of this genetic subtype with respect to ASD and ID. By studying the entire cohort, we defined common phenotypic features of POGZ individuals, including variable levels of developmental delay (DD) and more severe speech and language delay in comparison to the severity of motor delay and coordination issues. We also identified significant associations with vision problems, microcephaly, hyperactivity, a tendency to obesity, and feeding difficulties. Some features might be explained by the high expression of POGZ, particularly in the cerebellum and pituitary, early in fetal brain development. We conducted parallel studies in Drosophila by inducing conditional knockdown of the POGZ ortholog row, further confirming that dosage of POGZ, specifically in neurons, is essential for normal learning in a habituation paradigm. Combined, the data underscore the pathogenicity of loss-of-function mutations in POGZ and define a POGZ-related phenotype enriched in specific features.


Assuntos
Transtorno do Espectro Autista/genética , Deficiência Intelectual/genética , Transposases/genética , Adolescente , Adulto , Animais , Transtorno do Espectro Autista/diagnóstico , Criança , Pré-Escolar , Estudos de Coortes , Regulação para Baixo , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Exoma , Feminino , Técnicas de Silenciamento de Genes , Estudo de Associação Genômica Ampla , Humanos , Lactente , Deficiência Intelectual/diagnóstico , Transtornos do Desenvolvimento da Linguagem/diagnóstico , Transtornos do Desenvolvimento da Linguagem/genética , Modelos Lineares , Masculino , Microcefalia/diagnóstico , Microcefalia/genética , Mutação , Fenótipo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
PLoS One ; 11(2): e0149717, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26918704

RESUMO

BACKGROUND: Intellectual Disability (ID) is characterized by deficits in intellectual functions such as reasoning, problem-solving, planning, abstract thinking, judgment, and learning. As new avenues are emerging for treatment of genetically determined ID (such as Down's syndrome or Fragile X syndrome), it is necessary to identify objective reliable and sensitive outcome measures for use in clinical trials. OBJECTIVE: We developed a novel visual analogical reasoning paradigm, inspired by the Progressive Raven's Matrices, but appropriate for Intellectually Disabled patients. This new paradigm assesses reasoning and inhibition abilities in ID patients. METHODS: We performed behavioural analyses for this task (with a reaction time and error rate analysis, Study 1) in 96 healthy controls (adults and typically developed children older than 4) and 41 genetically determined ID patients (Fragile X syndrome, Down syndrome and ARX mutated patients). In order to establish and quantify the cognitive strategies used to solve the task, we also performed an eye-tracking analysis (Study 2). RESULTS: Down syndrome, ARX and Fragile X patients were significantly slower and made significantly more errors than chronological age-matched healthy controls. The effect of inhibition on error rate was greater than the matrix complexity effect in ID patients, opposite to findings in adult healthy controls. Interestingly, ID patients were more impaired by inhibition than mental age-matched healthy controls, but not by the matrix complexity. Eye-tracking analysis made it possible to identify the strategy used by the participants to solve the task. Adult healthy controls used a matrix-based strategy, whereas ID patients used a response-based strategy. Furthermore, etiologic-specific reasoning differences were evidenced between ID patients groups. CONCLUSION: We suggest that this paradigm, appropriate for ID patients and developmental populations as well as adult healthy controls, provides an objective and quantitative assessment of visual analogical reasoning and cognitive inhibition, enabling testing for the effect of pharmacological or behavioural intervention in these specific populations.


Assuntos
Deficiência Intelectual/psicologia , Pensamento , Adolescente , Adulto , Estudos de Casos e Controles , Cognição , Síndrome de Down/fisiopatologia , Síndrome de Down/psicologia , Feminino , Síndrome do Cromossomo X Frágil/fisiopatologia , Síndrome do Cromossomo X Frágil/psicologia , Proteínas de Homeodomínio/genética , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/fisiopatologia , Masculino , Pessoa de Meia-Idade , Mutação , Fatores de Transcrição/genética , Adulto Jovem
12.
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
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.
Genet Med ; 18(1): 49-56, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25790162

RESUMO

PURPOSE: Treacher Collins/Franceschetti syndrome (TCS; OMIM 154500) is a disorder of craniofacial development belonging to the heterogeneous group of mandibulofacial dysostoses. TCS is classically characterized by bilateral mandibular and malar hypoplasia, downward-slanting palpebral fissures, and microtia. To date, three genes have been identified in TCS:,TCOF1, POLR1D, and POLR1C. METHODS: We report a clinical and extensive molecular study, including TCOF1, POLR1D, POLR1C, and EFTUD2 genes, in a series of 146 patients with TCS. Phenotype-genotype correlations were investigated for 19 clinical features, between TCOF1 and POLR1D, and the type of mutation or its localization in the TCOF1 gene. RESULTS: We identified 92/146 patients (63%) with a molecular anomaly within TCOF1, 9/146 (6%) within POLR1D, and none within POLR1C. Among the atypical negative patients (with intellectual disability and/or microcephaly), we identified four patients carrying a mutation in EFTUD2 and two patients with 5q32 deletion encompassing TCOF1 and CAMK2A in particular. Congenital cardiac defects occurred more frequently among patients with TCOF1 mutation (7/92, 8%) than reported in the literature. CONCLUSION: Even though TCOF1 and POLR1D were associated with extreme clinical variability, we found no phenotype-genotype correlation. In cases with a typical phenotype of TCS, 6/146 (4%) remained with an unidentified molecular defect.


Assuntos
RNA Polimerases Dirigidas por DNA/genética , Disostose Mandibulofacial/genética , Proteínas Nucleares/genética , Fosfoproteínas/genética , Adolescente , Adulto , Sequência de Aminoácidos , Sequência de Bases , Criança , Feminino , Estudos de Associação Genética , Humanos , Masculino , Disostose Mandibulofacial/diagnóstico , Microcefalia/genética , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação , Fatores de Alongamento de Peptídeos/genética , Ribonucleoproteína Nuclear Pequena U5/genética , Deleção de Sequência , Adulto Jovem
15.
Eur J Hum Genet ; 24(6): 844-51, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26508576

RESUMO

Although 22q11.2 deletion syndrome (22q11.2DS) is the most recurrent human microdeletion syndrome associated with a highly variable phenotype, little is known about the condition's true incidence and the phenotype at diagnosis. We performed a multicenter, retrospective analysis of postnatally diagnosed patients recruited by members of the Association des Cytogénéticiens de Langue Française (the French-Speaking Cytogeneticists Association). Clinical and cytogenetic data on 749 cases diagnosed between 1995 and 2013 were collected by 31 French cytogenetics laboratories. The most frequent reasons for referral of postnatally diagnosed cases were a congenital heart defect (CHD, 48.6%), facial dysmorphism (49.7%) and developmental delay (40.7%). Since 2007 (the year in which array comparative genomic hybridization (aCGH) was introduced for the routine screening of patients with intellectual disability), almost all cases have been diagnosed using FISH (96.1%). Only 15 cases (all with an atypical phenotype) were diagnosed with aCGH; the deletion size ranged from 745 to 2904 kb. The deletion was inherited in 15.0% of cases and was of maternal origin in 85.5% of the latter. This is the largest yet documented cohort of patients with 22q11.2DS (the most commonly diagnosed microdeletion) from the same population. French cytogenetics laboratories diagnosed at least 108 affected patients (including fetuses) per year from among a national population of ∼66 million. As observed for prenatal diagnoses, CHDs were the most frequently detected malformation in postnatal diagnoses. The most common CHD in postnatal diagnoses was an isolated septal defect.


Assuntos
Síndrome da Deleção 22q11/diagnóstico , Testes Genéticos/estatística & dados numéricos , Síndrome da Deleção 22q11/epidemiologia , Síndrome da Deleção 22q11/genética , Adolescente , Adulto , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Feminino , França , Testes Genéticos/métodos , Humanos , Hibridização in Situ Fluorescente , Lactente , Recém-Nascido , Masculino , Herança Paterna
16.
Am J Med Genet A ; 167A(12): 3046-53, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26385851

RESUMO

Ductal plate malformations (DPM) present with a wide phenotypic spectrum comprising Von Meyenburg complexes (VMC), Caroli disease (CD), Caroli syndrome (CS), and autosomal recessive polycystic kidney disease (ARPKD). Variants in PKHD1 are responsible for ARPKD and CS with a high inter- and intra-familial phenotypic variability. Rare familial cases of CD had been reported and exceptional cases of CD are associated with PKHD1 variants. In a family of three siblings presenting with a wide spectrum of severity of DPM, we performed whole exome sequencing and identified two PKHD1 compound heterozygous variants (c.10444G>A; p.Arg3482Cys and c.5521C>T; p.Glu1841Lys), segregating with the symptoms. Two compound heterozygous PKHD1 variants, including one hypomorphic variant, were identified in two other familial cases of DPM with at least one patient presenting with CD. This report widens the phenotypic variability of PKHD1 variants to VMC, and others hepatic bile ducts malformations with inconstant renal phenotype in adults and highlights the important intra-familial phenotypic variability. It also showed that PKHD1 might be a major gene for CD. This work adds an example of the contribution of exome sequencing, not only in the discovery of new genes but also in expanding the phenotypic spectrum of well-known disease-associated genes, using reverse phenotyping.


Assuntos
Doenças dos Ductos Biliares/genética , Ductos Biliares Intra-Hepáticos/anormalidades , Mutação/genética , Rim Policístico Autossômico Recessivo/genética , Receptores de Superfície Celular/genética , Adulto , Doenças dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/embriologia , Ductos Biliares Intra-Hepáticos/patologia , Criança , Exoma/genética , Feminino , Predisposição Genética para Doença , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Rim Policístico Autossômico Recessivo/patologia , Prognóstico , Adulto Jovem
17.
Neurobiol Dis ; 80: 80-92, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26007637

RESUMO

Mutations in the KCNQ2 gene encoding the voltage-dependent potassium M channel Kv7.2 subunit cause either benign epilepsy or early onset epileptic encephalopathy (EOEE). It has been proposed that the disease severity rests on the inhibitory impact of mutations on M current density. Here, we have analyzed the phenotype of 7 patients carrying the p.A294V mutation located on the S6 segment of the Kv7.2 pore domain (Kv7.2(A294V)). We investigated the functional and subcellular consequences of this mutation and compared it to another mutation (Kv7.2(A294G)) associated with a benign epilepsy and affecting the same residue. We report that all the patients carrying the p.A294V mutation presented the clinical and EEG characteristics of EOEE. In CHO cells, the total expression of Kv7.2(A294V) alone, assessed by western blotting, was only 20% compared to wild-type. No measurable current was recorded in CHO cells expressing Kv7.2(A294V) channel alone. Although the total Kv7.2(A294V) expression was rescued to wild-type levels in cells co-expressing the Kv7.3 subunit, the global current density was still reduced by 83% compared to wild-type heteromeric channel. In a configuration mimicking the patients' heterozygous genotype i.e., Kv7.2(A294V)/Kv7.2/Kv7.3, the global current density was reduced by 30%. In contrast to Kv7.2(A294V), the current density of homomeric Kv7.2(A294G) was not significantly changed compared to wild-type Kv7.2. However, the current density of Kv7.2(A294G)/Kv7.2/Kv7.3 and Kv7.2(A294G)/Kv7.3 channels were reduced by 30% and 50% respectively, compared to wild-type Kv7.2/Kv7.3. In neurons, the p.A294V mutation induced a mislocalization of heteromeric mutant channels to the somato-dendritic compartment, while the p.A294G mutation did not affect the localization of the heteromeric channels to the axon initial segment. We conclude that this position is a hotspot of mutation that can give rise to a severe or a benign epilepsy. The p.A294V mutation does not exert a dominant-negative effect on wild-type subunits but alters the preferential axonal targeting of heteromeric Kv7 channels. Our data suggest that the disease severity is not necessarily a consequence of a strong inhibition of M current and that additional mechanisms such as abnormal subcellular distribution of Kv7 channels could be determinant.


Assuntos
Encéfalo/fisiopatologia , Epilepsia/genética , Canal de Potássio KCNQ2/genética , Canal de Potássio KCNQ2/fisiologia , Animais , Encéfalo/metabolismo , Células CHO , Células Cultivadas , Cricetulus , Epilepsia/diagnóstico , Epilepsia/fisiopatologia , Hipocampo/metabolismo , Humanos , Canal de Potássio KCNQ2/metabolismo , Mutação , Neurônios/metabolismo , Fenótipo
18.
Eur J Med Genet ; 58(2): 51-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25497044

RESUMO

Infantile Spasms syndrome (ISs) is a characterized by epileptic spasms occurring in clusters with an onset in the first year of life. West syndrome represents a subset of ISs that associates spasms in clusters, a hypsarrhythmia EEG pattern and a developmental arrest or regression. Aetiology of ISs is widely heterogeneous including many genetic causes. Many patients, however, remain without etiological diagnosis, which is critical for prognostic purpose and genetic counselling. In the present study, we performed genetic screening of 73 patients with different types of ISs by array-CGH and molecular analysis of 5 genes: CDKL5, STXBP1, KCNQ2, and GRIN2A, whose mutations cause different types of epileptic encephalopathies, including ISs, as well as MAGI2, which was suggested to be related to a subset of ISs. In total, we found a disease-causing mutation or CNV (Copy Number Variation) in 15% of the patients. These included 6 point mutations found in CDKL5 (n = 3) and STXBP1 (n = 3), 3 microdeletions (10 Mb in 2q24.3, 3.2 Mb in 5q14.3 including the region upstream to MEF2C, and 256 kb in 9q34 disrupting EHMT1), and 2 microduplications (671 kb in 2q24.3 encompassing SCN2A, and 11.93 Mb in Xq28). In addition, we discuss 3 CNVs as potential risk factors, including one 16p12.1 deletion, one intronic deletion of the NEDD4 gene, and one intronic deletion of CALN1 gene. The present findings highlight the efficacy of combined cytogenetic and targeted mutation screening to improve the diagnostic yield in patient with ISs.


Assuntos
Espasmos Infantis/genética , Calmodulina/genética , Proteínas de Transporte/genética , Criança , Pré-Escolar , Variações do Número de Cópias de DNA , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Feminino , Histona-Lisina N-Metiltransferase/genética , Humanos , Recém-Nascido , Canal de Potássio KCNQ2/genética , Fatores de Transcrição MEF2/genética , Masculino , Proteínas Munc18/genética , Mutação , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Ubiquitina-Proteína Ligases Nedd4 , Proteínas Serina-Treonina Quinases/genética , Receptores de N-Metil-D-Aspartato/genética , Síndrome , Ubiquitina-Proteína Ligases/genética
19.
Orphanet J Rare Dis ; 9: 25, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24528893

RESUMO

BACKGROUND: The c.429_452dup24 of the ARX gene is a rare genetic anomaly, leading to X-Linked Intellectual Disability without brain malformation. While in certain cases c.429_452dup24 has been associated with specific clinical patterns such as Partington syndrome, the consequence of this mutation has been also often classified as "non-specific Intellectual Disability". The present work aims at a more precise description of the clinical features linked to the c.429_452dup24 mutation. METHODS: We clinically reviewed all affected patients identified in France over a five-year period, i.e. 27 patients from 12 different families. Detailed cognitive, behavioural, and motor evaluation, as well as standardized videotaped assessments of oro-lingual and gestural praxis, were performed. In a sub-group of 13 ARX patients, kinematic and MRI studies were further accomplished to better characterize the motor impairment prevalent in the ARX patients group. To ensure that data were specific to the ARX gene mutation and did not result from low-cognitive functioning per se, a group of 27 age- and IQ-matched Down syndrome patients served as control. RESULTS: Neuropsychological and motor assessment indicated that the c.429_452dup24 mutation constitutes a recognizable clinical syndrome: ARX patients exhibiting Intellectual Disability, without primary motor impairment, but with a very specific upper limb distal motor apraxia associated with a pathognomonic hand-grip. Patients affected with the so-called Partington syndrome, which involves major hand dystonia and orolingual apraxia, exhibit the most severe symptoms of the disorder. The particular "reach and grip" impairment which was observed in all ARX patients, but not in Down syndrome patients, was further characterized by the kinematic data: (i) loss of preference for the index finger when gripping an object, (ii) major impairment of fourth finger deftness, and (iii) a lack of pronation movements. This lack of distal movement coordination exhibited by ARX patients is associated with the loss of independent digital dexterity and is similar to the distortion of individual finger movements and posture observed in Limb Kinetic Apraxia. CONCLUSION: These findings suggest that the ARX c.429_452dup24 mutation may be a developmental model for Limb Kinetic Apraxia.


Assuntos
Apraxias/genética , Extremidades/fisiopatologia , Duplicação Gênica , Proteínas de Homeodomínio/genética , Modelos Biológicos , Fatores de Transcrição/genética , Adolescente , Adulto , Fenômenos Biomecânicos , Estudos de Casos e Controles , Criança , Síndrome de Down/fisiopatologia , Humanos , Mutação , Adulto Jovem
20.
Mol Genet Metab ; 110(3): 263-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24090707

RESUMO

Creatine and guanidinoacetate are biomarkers of creatine metabolism. Their assays in body fluids may be used for detecting patients with primary creatine deficiency disorders (PCDD), a class of inherited diseases. Their laboratory values in blood and urine may vary with age, requiring that reference normal values are given within the age range. Despite the long known role of creatine for muscle physiology, muscle signs are not necessarily the major complaint expressed by PCDD patients. These disorders drastically affect brain function inducing, in patients, intellectual disability, autistic behavior and other neurological signs (delays in speech and language, epilepsy, ataxia, dystonia and choreoathetosis), being a common feature the drop in brain creatine content. For this reason, screening of PCDD patients has been repeatedly carried out in populations with neurological signs. This report is aimed at providing reference laboratory values and related age ranges found for a large scale population of patients with neurological signs (more than 6 thousand patients) previously serving as a background population for screening French patients with PCDD. These reference laboratory values and age ranges compare rather favorably with literature values for healthy populations. Some differences are also observed, and female participants are discriminated from male participants as regards to urine but not blood values including creatine on creatinine ratio and guanidinoacetate on creatinine ratio values. Such gender differences were previously observed in healthy populations; they might be explained by literature differential effects of testosterone and estrogen in adolescents and adults, and by estrogen effects in prepubertal age on SLC6A8 function. Finally, though they were acquired on a population with neurological signs, the present data might reasonably serve as reference laboratory values in any future medical study exploring abnormalities of creatine metabolism and transport.


Assuntos
Creatina/metabolismo , Grupo com Ancestrais do Continente Europeu , Glicina/análogos & derivados , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/metabolismo , Estudos de Casos e Controles , Criança , Pré-Escolar , Creatina/sangue , Creatina/urina , Feminino , França , Glicina/sangue , Glicina/metabolismo , Glicina/urina , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Valores de Referência , Fatores Sexuais , Adulto Jovem
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