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1.
Eur J Hum Genet ; 2019 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-31231136

RESUMO

We compared clinical validity of two non-invasive prenatal screening (NIPS) methods for fetal trisomies 13, 18, 21, and monosomy X. We recruited prospectively 2203 women at high risk of fetal aneuploidy and 1807 at baseline risk. Three-hundred and twenty-nine euploid samples were randomly removed. The remaining 1933 high risk and 1660 baseline-risk plasma aliquots were assigned randomly between four laboratories and tested with two index NIPS tests, blind to maternal variables and pregnancy outcomes. The two index tests used massively parallel shotgun sequencing (semiconductor-based and optical-based). The reference standard for all fetuses was invasive cytogenetic analysis or clinical examination at birth and postnatal follow-up. For each chromosome of interest, chromosomal ratios were calculated (number of reads for chromosome/total number of reads). Euploid samples' mean chromosomal ratio coefficients of variation were 0.48 (T21), 0.34 (T18), and 0.31 (T13). According to the reference standard, there were 155 cases of T21, 49 T18, 8 T13 and 22 45,X. Using a fetal fraction ≥4% to call results and a chromosomal ratio z-score of ≥3 to report a positive result, detection rates (DR), and false positive rates (FPR) were not statistically different between platforms: mean DR 99% (T21), 100%(T18, T13); 79%(45,X); FPR < 0.3% for T21, T18, T13, and <0.6% for 45,X. Both methods' negative predictive values in high-risk pregnancies were >99.8%, except for 45,X(>99.6%). Threshold analysis in high-risk pregnancies with different fetal fractions and z-score cut-offs suggested that a z-score cutoff to 3.5 for positive results improved test accuracy. Both sequencing platforms showed equivalent and excellent clinical validity.

2.
Genet Med ; 2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31092906

RESUMO

PURPOSE: Skeletal muscle growth and regeneration rely on muscle stem cells, called satellite cells. Specific transcription factors, particularly PAX7, are key regulators of the function of these cells. Knockout of this factor in mice leads to poor postnatal survival; however, the consequences of a lack of PAX7 in humans have not been established. METHODS: Here, we study five individuals with myopathy of variable severity from four unrelated consanguineous couples. Exome sequencing identified pathogenic variants in the PAX7 gene. Clinical examination, laboratory tests, and muscle biopsies were performed to characterize the disease. RESULTS: The disease was characterized by hypotonia, ptosis, muscular atrophy, scoliosis, and mildly dysmorphic facial features. The disease spectrum ranged from mild to severe and appears to be progressive. Muscle biopsies showed the presence of atrophic fibers and fibroadipose tissue replacement, with the absence of myofiber necrosis. A lack of PAX7 expression was associated with satellite cell pool exhaustion; however, the presence of residual myoblasts together with regenerating myofibers suggest that a population of PAX7-independent myogenic cells partially contributes to muscle regeneration. CONCLUSION: These findings show that biallelic variants in the master transcription factor PAX7 cause a new type of myopathy that specifically affects satellite cell survival.

3.
J Health Organ Manag ; 33(2): 204-220, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30950308

RESUMO

PURPOSE: The purpose of this paper is to gain a better understanding of the difficulties encountered in the hybrid roles of physician-managers (P-Ms), examine the impact of organizational constraints on the role conflicts experienced by P-Ms and explore the different ways their two roles are integrated. DESIGN/METHODOLOGY/APPROACH: A qualitative approach was adopted, using six focus groups made up of clinical co-managers, medical directors and P-Ms. In all, 43 different people were interviewed to obtain their perceptions of the day-to-day realities of the role of the P-M. The data collected were subsequently validated. FINDINGS: Although the expectations of the different groups involved regarding the role of P-Ms are well understood and shared, there are significant organizational constraints affecting what P-Ms are able to do in their day-to-day activities, and these constraints can result in role conflicts for the people involved. Such constraints also affect the ways P-Ms integrate the two roles. The authors identify three role hybridization profiles. PRACTICAL IMPLICATIONS: The results afford a better understanding of how organizational constraints might be used as levers of organizational change to achieve a better hybridization of the dual roles of P-Ms. ORIGINALITY/VALUE: This paper seeks to reach beyond a simple identification of constraints affecting the dual roles of P-Ms by analyzing how such constraints impact on these professionals' day-to-day activities. Results also enable us to further refine Katz and Kahn's (1966) role model, in addition to identifying hybridization profiles.

6.
Genet Med ; 2018 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-30206421

RESUMO

PURPOSE: Variants in IQSEC2, escaping X inactivation, cause X-linked intellectual disability with frequent epilepsy in males and females. We aimed to investigate sex-specific differences. METHODS: We collected the data of 37 unpublished patients (18 males and 19 females) with IQSEC2 pathogenic variants and 5 individuals with variants of unknown significance and reviewed published variants. We compared variant types and phenotypes in males and females and performed an analysis of IQSEC2 isoforms. RESULTS: IQSEC2 pathogenic variants mainly led to premature truncation and were scattered throughout the longest brain-specific isoform, encoding the synaptic IQSEC2/BRAG1 protein. Variants occurred de novo in females but were either de novo (2/3) or inherited (1/3) in males, with missense variants being predominantly inherited. Developmental delay and intellectual disability were overall more severe in males than in females. Likewise, seizures were more frequently observed and intractable, and started earlier in males than in females. No correlation was observed between the age at seizure onset and severity of intellectual disability or resistance to antiepileptic treatments. CONCLUSION: This study provides a comprehensive overview of IQSEC2-related encephalopathy in males and females, and suggests that an accurate dosage of IQSEC2 at the synapse is crucial during normal brain development.

7.
Clin Biochem ; 59: 69-77, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29958880

RESUMO

OBJECTIVES: Non-invasive prenatal aneuploidy testing (NIPT) by next-generation sequencing of circulating cell-free DNA in maternal plasma relies on chromosomal ratio (chrratio) measurements to detect aneuploid values that depart from euploid ratios. Diagnostic performances are known to depend on the fraction of fetal DNA (FF) present in maternal plasma, although how this translates into specific quantitative changes in specificity/positive predictive values and which other variables might also be important is not well understood. DESIGN & METHODS: To explore this issue, theoretical relationships between FF and various measures of diagnostic performances were assessed for a range of parameter values. Empirical data from three NIPT assays were then used to validate theoretical calculations. RESULTS: For a given positivity threshold, dramatic changes in specificity and positive predictive values (PPV) as a function of both FF and the coefficient of variation (CV) of the chrratio measurement were observed. Theoretically predicted and observed chrratio z-scores agreed closely, confirming the determinant impact of small changes in both FF and chrratio CV. CONCLUSIONS: Evaluation of NIPT assay performances therefore requires knowledge of the FF distribution in the population in which the test is intended to be used and, in particular, of the precise value of the assay chrratio CV for each chromosome or genomic region of interest. Laboratories offering NIPT testing should carefully measure these parameters to ensure test reliability and clinical usefulness in interpreting individual patients' results.


Assuntos
Aneuploidia , Diagnóstico Pré-Natal/métodos , Adulto , Transtornos Cromossômicos/sangue , Feminino , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Modelos Teóricos , Valor Preditivo dos Testes , Gravidez , Diagnóstico Pré-Natal/estatística & dados numéricos , Reprodutibilidade dos Testes
8.
Brain ; 2018 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-29985992

RESUMO

The transcription factor BCL11B is essential for development of the nervous and the immune system, and Bcl11b deficiency results in structural brain defects, reduced learning capacity, and impaired immune cell development in mice. However, the precise role of BCL11B in humans is largely unexplored, except for a single patient with a BCL11B missense mutation, affected by multisystem anomalies and profound immune deficiency. Using massively parallel sequencing we identified 13 patients bearing heterozygous germline alterations in BCL11B. Notably, all of them are affected by global developmental delay with speech impairment and intellectual disability; however, none displayed overt clinical signs of immune deficiency. Six frameshift mutations, two nonsense mutations, one missense mutation, and two chromosomal rearrangements resulting in diminished BCL11B expression, arose de novo. A further frameshift mutation was transmitted from a similarly affected mother. Interestingly, the most severely affected patient harbours a missense mutation within a zinc-finger domain of BCL11B, probably affecting the DNA-binding structural interface, similar to the recently published patient. Furthermore, the most C-terminally located premature termination codon mutation fails to rescue the progenitor cell proliferation defect in hippocampal slice cultures from Bcl11b-deficient mice. Concerning the role of BCL11B in the immune system, extensive immune phenotyping of our patients revealed alterations in the T cell compartment and lack of peripheral type 2 innate lymphoid cells (ILC2s), consistent with the findings described in Bcl11b-deficient mice. Unsupervised analysis of 102 T lymphocyte subpopulations showed that the patients clearly cluster apart from healthy children, further supporting the common aetiology of the disorder. Taken together, we show here that mutations leading either to BCL11B haploinsufficiency or to a truncated BCL11B protein clinically cause a non-syndromic neurodevelopmental delay. In addition, we suggest that missense mutations affecting specific sites within zinc-finger domains might result in distinct and more severe clinical outcomes.

9.
J Med Genet ; 55(5): 316-321, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29599419

RESUMO

BACKGROUND: Chitayat-Hall syndrome, initially described in 1990, is a rare condition characterised by distal arthrogryposis, intellectual disability, dysmorphic features and hypopituitarism, in particular growth hormone deficiency. The genetic aetiology has not been identified. METHODS AND RESULTS: We identified three unrelated families with a total of six affected patients with the clinical manifestations of Chitayat-Hall syndrome. Through whole exome or whole genome sequencing, pathogenic variants in the MAGEL2 gene were identified in all affected patients. All disease-causing sequence variants detected are predicted to result in a truncated protein, including one complex variant that comprised a deletion and inversion. CONCLUSIONS: Chitayat-Hall syndrome is caused by pathogenic variants in MAGEL2 and shares a common aetiology with the recently described Schaaf-Yang syndrome. The phenotype of MAGEL2-related disorders is expanded to include growth hormone deficiency as an important and treatable complication.

10.
Ann Neurol ; 83(6): 1089-1095, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29518281

RESUMO

VPS13 protein family members VPS13A through VPS13C have been associated with various recessive movement disorders. We describe the first disease association of rare recessive VPS13D variants including frameshift, missense, and partial duplication mutations with a novel complex, hyperkinetic neurological disorder. The clinical features include developmental delay, a childhood onset movement disorder (chorea, dystonia, or tremor), and progressive spastic ataxia or paraparesis. Characteristic brain magnetic resonance imaging shows basal ganglia or diffuse white matter T2 hyperintensities as seen in Leigh syndrome and choreoacanthocytosis. Muscle biopsy in 1 case showed mitochondrial aggregates and lipidosis, suggesting mitochondrial dysfunction. These findings underline the importance of the VPS13 complex in neurological diseases and a possible role in mitochondrial function. Ann Neurol 2018;83:1089-1095.

11.
J Bone Miner Res ; 32(9): 1853-1859, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28543917

RESUMO

Congenital disorders of glycosylation (CDGs) affect multiple systems and present a broad spectrum of clinical features, often including skeletal dysplasia. Exome sequencing has led to the identification of new CDG genes. Immune and skeletal phenotypes associated with mutations in PGM3, encoding a protein that converts N-acetyl-glucosamine-6-phosphate into N-acetyl-glucosamine-1-phosphate, were recently reported. Through exome sequencing, we identified a novel homozygous mutation (c.1135T>C; p.Phe379Leu) in PGM3 in two siblings with bone marrow failure, severe combined immunodeficiency, renal and intestinal malformations, and a skeletal dysplasia resembling Desbuquois dysplasia. Severe respiratory compromise secondary to lung hypoplasia and pulmonary hypertension, and intestinal obstruction led to their demise. We thus report the most severe phenotype described so far associated with PGM3 mutations. This CDG should be considered in the presence of skeletal dysplasia associated with severe immunodeficiency. © 2017 American Society for Bone and Mineral Research.


Assuntos
Doenças do Desenvolvimento Ósseo/genética , Doenças da Medula Óssea/genética , Anormalidades Musculoesqueléticas/genética , Mutação , Fosfoglucomutase/genética , Imunodeficiência Combinada Severa/genética , Feminino , Humanos , Recém-Nascido , Masculino
12.
Am J Med Genet A ; 2017 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-28449304

RESUMO

DNMT3A-Overgrowth Syndrome (also known as Tatton-Brown-Rahman Syndrome) (MIM 615879) has recently been described in 13 individuals with de novo heterozygous mutations in DNMT3A gene. This autosomal dominant condition is characterized by overgrowth, dysmorphic facial features and moderate intellectual disability. Missense and truncating point mutations, a small in-frame deletion, as well as microdeletion 2p23 have been reported. Moreover, DNMT3A is commonly somatically mutated in acute myeloid leukemia. We herein report a family with two siblings and their father affected by the syndrome. The proband is a 12 year-old boy with tall stature, macrocephaly, facial dysmorphism, and intellectual disability. His 10-year-old sister also has learning difficulties, overgrowth and mild facial dysmorphism. Their father is a 49 year-old man with tall stature, macrocephaly, learning difficulties, and minor facial dysmorphism. He had a right occipital osteoma removed at 20 years of age. A heterozygous splice site mutation NM_022552.4 (DNMT3A): c.2323-2A > T was found in the proband by whole exome sequencing analysis and by targeted Sanger Sequencing for the proband's sister and father. This mutation has not been previously reported and is believed to be pathogenic. Indeed, this substitution involves a highly conserved canonical splice site and is predicted to cause exon skipping. This is the first report of a familial transmission of DNMT3A-Overgrowth Syndrome, supporting the autosomal dominant inheritance. The proband's phenotype is more severe than that of his two other affected family members, which illustrates variable expressivity in the syndrome.

13.
Fish Shellfish Immunol ; 62: 332-340, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28159692

RESUMO

Protease inhibitors are an extremely diverse group of proteins that control the proteolytic activities of proteases and play a crucial role in biological processes including host defenses. The I84 family of protease inhibitors in the MEROPS database currently consists of cvSI-1 and cvSI-2, two novel serine protease inhibitors purified and characterized from the eastern oyster Crassostrea virginica plasma and believed to play a role in host defense and disease resistance. In the present study, a third member of I84 family, named cvSI-3, was identified from C. virginica by cDNA cloning and sequencing. The full cvSI-3 cDNA was composed of 342 bp including a 255 bp open reading frame (ORF) that encodes an 84-amino acid peptide. The mature cvSI-3 molecule was predicted to have 68 amino acid residues after removal of a 16-amino acid signal peptide, with a calculated molecular mass of 7724.5 Da and a theoretical isoelectric point (pI) of 6.28. CvSI-3 amino acid sequence shared 41% identity with cvSI-2 and 37% identity with cvSI-1, which included 12 conserved cysteines. Quantitative real-time PCR determined that cvSI-3 gene expressed primarily in oyster digestive glands. Real-time PCR also detected that cvSI-1, cvSI-2 and cvSI-3 expression levels in digestive glands varied significantly, with cvSI-2 showing the highest expression level and cvSI-3 the lowest. Additionally, a significant correlation was detected between cvSI-2 and cvSI-3 mRNAs levels. Searches into sequence databases using cvSI-1, cvSI-2 and cvSI-3 as queries retrieved ESTs suggesting the possible existence of at least 9 more I84 family members in eastern oysters and of I84 family protease inhibitors in various bivalve and gastropod species. Moreover, orthologs of all C. virginica I84 family members or potential member genes were found to be present in the C. gigas genome, and their distributions among species provided important information about the evolution of the I84 family of protease inhibitors. It appears that the I84 family of protease inhibitors is widely distributed and actively evolving in the Phylum Mollusca.


Assuntos
Inibidores de Serino Proteinase/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Crassostrea , DNA Complementar/genética , DNA Complementar/metabolismo , Filogenia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Inibidores de Serino Proteinase/química , Inibidores de Serino Proteinase/metabolismo
14.
Am J Med Genet A ; 170A(5): 1225-35, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26789910

RESUMO

Mutations in chromodomain helicase DNA-binding domain 8 (CHD8) have been identified in independent genotyping studies of autism spectrum disorder. To better understand the phenotype associated with CHD8 mutations, we genotyped all CHD8 exons in carefully assessed cohorts of autism (n = 142), schizophrenia (SCZ; n = 143), and intellectual disability (ID; n = 94). We identified one frameshift mutation, seven non-synonymous variants, and six synonymous variants. The frameshift mutation, p.Asn2092Lysfs*2, which creates a premature stop codon leading to the loss of 212 amino acids of the protein, was from an autism case on whom we present multiple clinical assessments and pharmacological treatments spanning more than 10 years. RNA and protein analysis support a model where the transcript generated from the mutant allele results in haploinsufficiency of CHD8. This case report supports the association of CHD8 mutations with classical autism, macrocephaly, infantile hypotonia, speech delay, lack of major ID, and psychopathology in late adolescence caused by insufficient dosage of CHD8. Review of 16 other CHD8 mutation cases suggests that clinical features and their severity vary considerably across individuals; however, these data support a CHD8 mutation syndrome, further highlighting the importance of genomic medicine to guide clinical assessment and treatment.


Assuntos
Transtorno do Espectro Autista/genética , Proteínas de Ligação a DNA/genética , Esquizofrenia/genética , Fatores de Transcrição/genética , Adolescente , Transtorno do Espectro Autista/fisiopatologia , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Éxons/genética , Feminino , Mutação da Fase de Leitura , Regulação da Expressão Gênica no Desenvolvimento , Genótipo , Humanos , Masculino , Esquizofrenia/fisiopatologia
15.
Stress Health ; 32(5): 569-577, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26644043

RESUMO

This study examines the associations between health and stress management (HSM) practices and mental-health disability claims. Data from the Salveo study was collected during 2009-2012 within 60 workplaces nested in 37 companies located in Canada (Quebec) and insured by a large insurance company. In each company, 1 h interviews were conducted with human resources managers in order to obtain data on 63 HSM practices. Companies and workplaces were sorted into the low-claims and high-claims groups according to the median rate of the population of the insurer's corporate clients. Logistic regression adjusted for design effect and multidimensional scaling was used to analyse the data. After controlling for company size and economic sector, task design, demands control, gratifications, physical activity and work-family balance were associated with low mental-health disability claims rates. Further analyses revealed three company profiles that were qualified as laissez-faire, integrated and partially integrated approaches to HSM. Of the three, the integrated profile was associated with low mental-health disability claims rates. The results of this study provide evidence-based guidance for a better control of mental-health disability claims. Copyright © 2015 John Wiley & Sons, Ltd.


Assuntos
Demandas Administrativas em Assistência à Saúde/estatística & dados numéricos , Pessoas com Deficiência Mental/estatística & dados numéricos , Doenças Profissionais/prevenção & controle , Serviços de Saúde do Trabalhador/estatística & dados numéricos , Estresse Psicológico/prevenção & controle , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quebeque
16.
Eur J Hum Genet ; 24(6): 944-8, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26508570

RESUMO

Childhood-onset schizophrenia (COS), defined by the onset of illness before age 13 years, is a rare severe neurodevelopmental disorder of unknown etiology. Recently, sequencing studies have identified rare, potentially causative de novo variants in sporadic cases of adult-onset schizophrenia and autism. In this study, we performed exome sequencing of 17 COS trios in order to test whether de novo variants could contribute to this disease. We identified 20 de novo variants in 17 COS probands, which is consistent with the de novo mutation rate reported in the adult form of the disease. Interestingly, the missense de novo variants in COS have a high likelihood for pathogenicity and were enriched for genes that are less tolerant to variants. Among the genes found disrupted in our study, SEZ6, RYR2, GPR153, GTF2IRD1, TTBK1 and ITGA6 have been previously linked to neuronal function or to psychiatric disorders, and thus may be considered as COS candidate genes.


Assuntos
Mutação de Sentido Incorreto , Esquizofrenia Infantil/genética , Criança , Exoma , Feminino , Estudo de Associação Genômica Ampla , Humanos , Integrina alfa6/genética , Masculino , Proteínas Musculares/genética , Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinases/genética , Receptores Acoplados a Proteínas-G/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Transativadores/genética
17.
Hum Mol Genet ; 24(10): 2841-7, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25652405

RESUMO

Addition of the trinucleotide cytosine/cytosine/adenine (CCA) to the 3' end of transfer RNAs (tRNAs) is essential for translation and is catalyzed by the enzyme TRNT1 (tRNA nucleotidyl transferase), which functions in both the cytoplasm and mitochondria. Exome sequencing revealed TRNT1 mutations in two unrelated subjects with different clinical features. The first presented with acute lactic acidosis at 3 weeks of age and developed severe developmental delay, hypotonia, microcephaly, seizures, progressive cortical atrophy, neurosensorial deafness, sideroblastic anemia and renal Fanconi syndrome, dying at 21 months. The second presented at 3.5 years with gait ataxia, dysarthria, gross motor regression, hypotonia, ptosis and ophthalmoplegia and had abnormal signals in brainstem and dentate nucleus. In subject 1, muscle biopsy showed combined oxidative phosphorylation (OXPHOS) defects, but there was no OXPHOS deficiency in fibroblasts from either subject, despite a 10-fold-reduction in TRNT1 protein levels in fibroblasts of the first subject. Furthermore, in normal controls, TRNT1 protein levels are 10-fold lower in muscle than in fibroblasts. High resolution northern blots of subject fibroblast RNA suggested incomplete CCA addition to the non-canonical mitochondrial tRNA(Ser(AGY)), but no obvious qualitative differences in other mitochondrial or cytoplasmic tRNAs. Complete knockdown of TRNT1 in patient fibroblasts rendered mitochondrial tRNA(Ser(AGY)) undetectable, and markedly reduced mitochondrial translation, except polypeptides lacking Ser(AGY) codons. These data suggest that the clinical phenotypes associated with TRNT1 mutations are largely due to impaired mitochondrial translation, resulting from defective CCA addition to mitochondrial tRNA(Ser(AGY)), and that the severity of this biochemical phenotype determines the severity and tissue distribution of clinical features.


Assuntos
Mitocôndrias/genética , Doenças Mitocondriais/genética , Mutação , Biossíntese de Proteínas/genética , RNA Nucleotidiltransferases/genética , RNA de Transferência de Serina/metabolismo , Criança , Pré-Escolar , Exoma , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Mitocôndrias/metabolismo , RNA Nucleotidiltransferases/metabolismo , Análise de Sequência de DNA , Síndrome
18.
Eur J Hum Genet ; 23(9): 1266-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25407000

RESUMO

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is characterized by marked dilatation of the bladder and microcolon and decreased intestinal peristalsis. Recent studies indicate that heterozygous variants in ACTG2, which codes for a smooth muscle actin, cause MMIHS. However, such variants do not explain MMIHS cases that show an autosomal recessive mode of inheritance. We performed exome sequencing in a newborn with MMIHS and prune belly phenotype whose parents are consanguineous and identified a homozygous variant (c.3598A>T: p.Lys1200Ter) in MYH11, which codes for the smooth muscle myosin heavy chain. Previous studies showed that loss of Myh11 function in mice causes a bladder and intestinal phenotype that is highly reminiscent of MMIHS. All together, these observations strongly suggest that loss-of-function variants in MYH11 cause MMIHS. The documentation of variants in ACTG2 and MYH11 thus points to the involvement of the contractile apparatus of the smooth muscle in MMIHS. Interestingly, dominant-negative variants in MYH11 have previously been shown to cause thoracic aortic aneurism and dilatation. Different mechanisms of MYH11 disruption may thus lead to distinct patterns of smooth muscle dysfunction.


Assuntos
Anormalidades Múltiplas/genética , Colo/anormalidades , Homozigoto , Pseudo-Obstrução Intestinal/genética , Mutação , Cadeias Pesadas de Miosina/genética , Síndrome do Abdome em Ameixa Seca/genética , Bexiga Urinária/anormalidades , Anormalidades Múltiplas/metabolismo , Anormalidades Múltiplas/patologia , Sequência de Bases , Colo/metabolismo , Colo/patologia , Consanguinidade , Exoma , Expressão Gênica , Humanos , Recém-Nascido , Mucosa Intestinal/metabolismo , Obstrução Intestinal/metabolismo , Obstrução Intestinal/patologia , Pseudo-Obstrução Intestinal/complicações , Pseudo-Obstrução Intestinal/metabolismo , Pseudo-Obstrução Intestinal/patologia , Intestinos/patologia , Masculino , Dados de Sequência Molecular , Síndrome do Abdome em Ameixa Seca/complicações , Síndrome do Abdome em Ameixa Seca/metabolismo , Síndrome do Abdome em Ameixa Seca/patologia , Análise de Sequência de DNA , Bexiga Urinária/metabolismo , Bexiga Urinária/patologia
19.
PLoS Genet ; 10(9): e1004580, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25188300

RESUMO

SHANK genes code for scaffold proteins located at the post-synaptic density of glutamatergic synapses. In neurons, SHANK2 and SHANK3 have a positive effect on the induction and maturation of dendritic spines, whereas SHANK1 induces the enlargement of spine heads. Mutations in SHANK genes have been associated with autism spectrum disorders (ASD), but their prevalence and clinical relevance remain to be determined. Here, we performed a new screen and a meta-analysis of SHANK copy-number and coding-sequence variants in ASD. Copy-number variants were analyzed in 5,657 patients and 19,163 controls, coding-sequence variants were ascertained in 760 to 2,147 patients and 492 to 1,090 controls (depending on the gene), and, individuals carrying de novo or truncating SHANK mutations underwent an extensive clinical investigation. Copy-number variants and truncating mutations in SHANK genes were present in ∼1% of patients with ASD: mutations in SHANK1 were rare (0.04%) and present in males with normal IQ and autism; mutations in SHANK2 were present in 0.17% of patients with ASD and mild intellectual disability; mutations in SHANK3 were present in 0.69% of patients with ASD and up to 2.12% of the cases with moderate to profound intellectual disability. In summary, mutations of the SHANK genes were detected in the whole spectrum of autism with a gradient of severity in cognitive impairment. Given the rare frequency of SHANK1 and SHANK2 deleterious mutations, the clinical relevance of these genes remains to be ascertained. In contrast, the frequency and the penetrance of SHANK3 mutations in individuals with ASD and intellectual disability-more than 1 in 50-warrant its consideration for mutation screening in clinical practice.


Assuntos
Transtornos Globais do Desenvolvimento Infantil/genética , Transtornos Cognitivos/genética , Mutação/genética , Proteínas do Tecido Nervoso/genética , Estudos de Casos e Controles , Criança , Cognição/fisiologia , Variações do Número de Cópias de DNA/genética , Feminino , Humanos , Deficiência Intelectual/genética , Masculino , Neurônios/fisiologia , Sinapses/genética
20.
Am J Hum Genet ; 94(2): 268-77, 2014 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-24388663

RESUMO

Hereditary spastic paraplegias (HSPs) are clinically and genetically heterogeneous neurological conditions. Their main pathogenic mechanisms are thought to involve alterations in endomembrane trafficking, mitochondrial function, and lipid metabolism. With a combination of whole-genome mapping and exome sequencing, we identified three mutations in REEP2 in two families with HSP: a missense variant (c.107T>A [p.Val36Glu]) that segregated in the heterozygous state in a family with autosomal-dominant inheritance and a missense change (c.215T>A [p.Phe72Tyr]) that segregated in trans with a splice site mutation (c.105+3G>T) in a family with autosomal-recessive transmission. REEP2 belongs to a family of proteins that shape the endoplasmic reticulum, an organelle that was altered in fibroblasts from an affected subject. In vitro, the p.Val36Glu variant in the autosomal-dominant family had a dominant-negative effect; it inhibited the normal binding of wild-type REEP2 to membranes. The missense substitution p.Phe72Tyr, in the recessive family, decreased the affinity of the mutant protein for membranes that, together with the splice site mutation, is expected to cause complete loss of REEP2 function. Our findings illustrate how dominant and recessive inheritance can be explained by the effects and nature of mutations in the same gene. They have also important implications for genetic diagnosis and counseling in clinical practice because of the association of various modes of inheritance to this new clinico-genetic entity.


Assuntos
Proteínas de Membrana/genética , Paraplegia Espástica Hereditária/genética , Sequência de Aminoácidos , Animais , Células COS , Cercopithecus aethiops , Mapeamento Cromossômico , Exoma , Feminino , Heterozigoto , Humanos , Masculino , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Linhagem , Fenótipo , Paraplegia Espástica Hereditária/patologia
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