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1.
Ethique Sante ; 17(4): 220-225, 2020 Dec.
Artigo em Francês | MEDLINE | ID: mdl-32837547

RESUMO

What are the ethical issues in connection with the support of the most vulnerable people in a context of health crisis, forcing them to be confined? Because the concept of vulnerability is broad and complex, the "Espace éthique PACA-Corse" (PACA-Corsica Ethical Structure) has taken a particular interest in the care of children with disabilities, children entrusted to child welfare services and people with psychiatric disorders. Confinement has led to a reorganisation of the access to healthcare services and medico-social support, possibly revealing or aggravating some situations of vulnerability, or even pushing aside certain people. Those most isolated or at risk of abuse may have experienced a double confinement. How to identify and respond to the needs of people already in vulnerable situations before confinement, who, isolated in the epidemic context, have seen their vulnerabilities increase? While new ways of working have been introduced in times of containment, some were interesting, others have shown their limits. The challenge was to find the right measure to address the specificity of each situation, to activate care networks in an effective and supportive manner, despite limited resources and the emergency context. The difficulty was to make protocols and care values coexist, acting in a reactive and creative way. While revealing vulnerabilities, this period has required both humility toward uncertainty and a duty of responsibility to care for those most in need.

2.
Arch Pediatr ; 24(4): 373-383, 2017 Apr.
Artigo em Francês | MEDLINE | ID: mdl-28242148

RESUMO

The advent of next generation sequencing (NGS) technologies is so scale-changing that it modifies molecular diagnostics indications and induces laboratories to rethink their diagnostic strategies, until now based on the Sanger sequencing routine. Several high-throughput approaches are available from the sequencing of a gene panel, to an exome, or even a genome. In all cases, a tremendous amount of data is generated, which has to be filtered, interpreted and analyzed using powerful bioinformatics tools. In parallel, ethical considerations are raised to avoid the potential drifts of these powerful approaches. In all medical fields, and particularly in pediatrics, this new strategy offers better efficacy and faster mutation identification, allowing better support and care for patients and their families and even improving genetic counseling. In the present paper, we discuss the different NGS-based approaches and strategies as well as the issues involved in these new technologies applied to molecular diagnosis of rare diseases. Altogether, rare diseases affect more than 3 million people in France and are responsible for about one-third of childhood deaths.


Assuntos
Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/tendências , Análise de Sequência de DNA/métodos , Análise de Sequência de DNA/tendências , Criança , Análise Mutacional de DNA/métodos , Análise Mutacional de DNA/tendências , Exoma/genética , Previsões , França , Aconselhamento Genético/métodos , Aconselhamento Genético/tendências , Genoma/genética , Humanos
3.
Clin Genet ; 87(5): 488-91, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24835530

RESUMO

Array comparative genomic hybridization (aCGH) has progressively replaced conventional karyotype in the diagnostic strategy of intellectual disability (ID) and congenital malformations. This technique increases not only the diagnostic rate but also the possibility of finding unexpected variants unrelated to the indication of referral, namely incidental findings. The incidental finding of copy number variants (CNVs) located in X-linked genes in girls addresses the crucial question of genetic counseling in the family. We report here five cases of CNVs involving the dystrophin gene detected by aCGH in girls referred for developmental delay, without any family history of dystrophinopathy. The rearrangements included three in-frame deletions; one maternally and two paternally inherited, and two frameshift duplications: one de novo and one from undetermined inheritance. In two cases, the deletion identified in a girl was transmitted by the asymptomatic father. In the case of the maternally inherited deletion, prenatal diagnosis of dystrophinopathy was proposed for an ongoing pregnancy, whereas the cause of developmental delay in the index case remained unknown. Through these cases, we discussed the challenges of genetic counseling in the family, regarding the predictive issues for male individuals at risk for a muscular dystrophy without precise knowledge of the clinical consequences of some CNVs in the DMD gene.


Assuntos
Hibridização Genômica Comparativa , Heterozigoto , Achados Incidentais , Pré-Escolar , Variações do Número de Cópias de DNA , Distrofina/genética , Família , Feminino , Aconselhamento Genético , Humanos , Lactente , Distrofias Musculares/diagnóstico , Distrofias Musculares/genética
4.
Gynecol Obstet Fertil ; 39(4): 198-204, 2011 Apr.
Artigo em Francês | MEDLINE | ID: mdl-21435934

RESUMO

OBJECTIVE: To evaluate the caregivers' opinions regarding decision-making in termination of pregnancy (TOP) for fetal anomaly. MATERIAL AND METHODS: Questionnaire survey using a semi-structured survey based on visual analogue scales, sent to all multidisciplinary centres for prenatal diagnosis in France. Answers were received from 26 centres nation-wide. RESULTS: Response rate was 39% (213 responses received over 550 questionnaires sent). Fifty-five percent of respondents were women, 90% physicians, 7,5% midwives. A vast majority (69.8%) believes that their own convictions play a bigger role in decision in real practice than in their ideal. The major decisional factors in decision-making for TOP are: the long-term prognosis of the anomaly, a specialized opinion on its curability, the quality of the information given to the future parents, their expressed opinion, the existence of a multidisciplinary decision, the ability of the future parents to understand the medical data, the obtention of a medical consensus, the proof level of the medical information. For only 55% of the respondents, the current legal framework is adequate to manage the situations that result from prenatal diagnostic practices today. The question of late third-trimester TOP raises ethical debate: over a third (37%) see no ethical difference between TOP and withdrawal of care during the neonatal period; the majority (48% versus 43%) feel that ethically speaking a neonate and a foetus at 39 weeks gestational age (GA) should not be treated differently; 37% of the respondents feel that current practice is likely to lead to eugenism. DISCUSSION AND CONCLUSION: As far as TOP is concerned, the huge discrepancies in responses from the professionals highlight the ongoing ethical debate, especially concerning the concept of informed choice in TOP, which we believe should be entirely revisited.


Assuntos
Aborto Induzido/psicologia , Anormalidades Congênitas/psicologia , Tomada de Decisões , Atitude do Pessoal de Saúde , Feminino , França , Inquéritos Epidemiológicos , Humanos , Masculino , Pais/psicologia , Gravidez , Diagnóstico Pré-Natal/psicologia , Inquéritos e Questionários
5.
Eur J Obstet Gynecol Reprod Biol ; 151(2): 143-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20430509

RESUMO

OBJECTIVES: This study was performed to understand the parental attitudes, needs and ethical issues associated with perinatal death, to assist in the development of interventions for bereaved families. STUDY DESIGN: We conducted a qualitative descriptive survey of parental experiences with perinatal death. We developed a questionnaire based on the Delphi method, conducted semi-directed interviews or asked subjects to return the questionnaire by post. As a secondary analysis, we examined whether certain ethical principles (i.e., the concepts of beneficence, nonmaleficence, autonomy, and justice) were encountered by the study participants. The study population consisted of families who had experienced perinatal death in the maternity department of a French university hospital, as well as members of bereaved parent support groups. RESULTS: Six of the 12 parents who participated in the survey were members of a support group. Responses were analyzed according to precise objectives and grouped according to key themes. In particular, we studied deaths that occurred during neonatal palliative care and deaths relating to multiple pregnancies. Parents expressed opinions about the caregivers' practices (e.g., which practices were beneficial and detrimental). Half of the parents did not feel that their feelings and decisions were respected according to ethical principles. Understanding the experience of parents allows staff to reconsider and change their practices. CONCLUSIONS: By understanding parents' feelings toward neonatal death, caregivers can better assist with the grieving process. Our study reveals parents' attitudes toward the ethical decision-making process and shows that it is difficult for perinatal medicine caregivers to respect parents' autonomy.


Assuntos
Morte , Pesar , Pais/psicologia , Mortalidade Perinatal , Atitude Frente a Morte , Ética , Feminino , Humanos , Recém-Nascido , Entrevistas como Assunto , Masculino , Gravidez , Grupos de Autoajuda , Inquéritos e Questionários
6.
Pathol Biol (Paris) ; 58(5): 396-401, 2010 Oct.
Artigo em Francês | MEDLINE | ID: mdl-20116936

RESUMO

This article focuses on six questions raised by genetic testing in human: (1) the use of genetic tests, (2) information given to relatives of patients affected with genetic disorders, (3) prenatal and preimplantatory diagnosis for late onset genetic diseases and the use of pangenomic tests in prenatal diagnosis, (4) direct-to-consumer genetic testing, (5) population screening in the age of genomic medicine and (6) incidental findings when genetic testing are used.


Assuntos
Testes Genéticos/legislação & jurisprudência , Confidencialidade/ética , Confidencialidade/legislação & jurisprudência , Saúde da Família , Feminino , França , Testes Genéticos/ética , Humanos , Masculino , Gravidez , Diagnóstico Pré-Implantação/ética , Diagnóstico Pré-Natal/ética , Autocuidado
8.
Hum Reprod ; 18(10): 2058-66, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14507821

RESUMO

Balanced complex chromosomal rearrangements are very rare events in the human population. Translocations involving three or more chromosomes frequently lead to a severe reproductive impairment secondary to meiotic disturbance in males and to chromosomal imbalance in gametes of females. We report a new familial case of complex chromosome anomaly involving chromosomes 13, 14 and 22. Cytogenetic investigations showed a complex chromosomal chromosome rearrangement involving: (i) a Robertsonian translocation between chromosomes 13 and 14; and (ii) a reciprocal translocation between the long arms of chromosome 14 and the long arm of chromosome 22. The aetiology of the translocation was characterized by conventional fluorescence in-situ hybridization (FISH) studies and routine R- and G-banding (RTBG and GBTG) combined with alpha and beta satellite centromeric FISH probes. Predicted configuration of the hexavalent at pachytene stage of meiosis was used to consider the modes of segregation; only two configurations resulted in a normal or balanced gamete karyotype. Reproductive management and genetic counselling are discussed.


Assuntos
Cromossomos Humanos Par 13/genética , Cromossomos Humanos Par 14/genética , Cromossomos Humanos Par 22/genética , Rearranjo Gênico , Infertilidade/genética , Adulto , Segregação de Cromossomos , Análise Citogenética , DNA , Feminino , Genótipo , Humanos , Hibridização in Situ Fluorescente/métodos , Cariotipagem , Meiose , Linhagem , Translocação Genética
9.
Neuromuscul Disord ; 12(1): 4-12, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11731278

RESUMO

The clinico-pathological features of 17 patients displaying a myopathy with lobulated (trabeculated) fibers are reported. All these patients had a limb girdle phenotype and at least 20% of lobulated fibers in their muscle biopsies. There were ten females and seven males. The onset of symptoms ranged from 2 to 55 years (mean 24). The average age at the time of muscle biopsy was 39 (range 3-63). Interestingly, in six patients, high prevalence of lobulated fibers was observed at the second biopsy only, performed on average 11 years after the first or in another muscle. Six patients had a suggestively positive family history. Facial weakness was noted in two patients (genetic study confirmed FSH dystrophy). The course and the severity of weakness varied from one patient to another. Immunohistochemistry and Western blot analyses revealed one Duchenne carrier, one alpha-sarcoglycanopathy, no dysferlinopathy and four calpain deficiencies (including one patient with FSH dystrophy), but SSCP revealed mutation in the calpain gene in only one of the patients. These results show that (1) myopathies with lobulated fibers are clinically and genetically heterogeneous, (2) lack of calpain expression by Western blot analysis is not always associated with null mutation, (3) a molecular diagnosis is made in less than 40% of myopathy with lobulated fibers, (4) when observed, lobulated fibers are most prominent in proximal muscles and require time to appear.


Assuntos
Proteínas de Membrana , Fibras Musculares Esqueléticas/patologia , Distrofias Musculares/etiologia , Distrofias Musculares/patologia , Adolescente , Adulto , Biópsia , Calpaína/análise , Calpaína/genética , Pré-Escolar , Disferlina , Distrofina/análise , Distrofina/genética , Feminino , Hormônio Foliculoestimulante/genética , Expressão Gênica , Heterogeneidade Genética , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Proteínas Musculares/análise , Proteínas Musculares/genética , Distrofias Musculares/genética , Mutação , Fenótipo
11.
Am J Med Genet ; 95(1): 10-2, 2000 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-11074487

RESUMO

The urofacial syndrome (UFS) or Ochoa syndrome has been reported as a rare autosomal recessive disorder comprising a uropathy and facial abnormalities. The gene was mapped on chromosome region 10q23-q24. We report the first European cases of UFS. Haplotype analyses in our French family were compared with those previously described in patients from Columbia and America (literature data). The results are compatible with the same localization of the critical region and favor the hypothesis of genetic homogeneity.


Assuntos
Face/anormalidades , Obstrução Uretral/genética , Adolescente , Cromossomos Humanos Par 10/genética , Saúde da Família , Feminino , França , Haplótipos , Humanos , Masculino , Repetições de Microssatélites , Síndrome , Obstrução Uretral/congênito , Obstrução Uretral/patologia
12.
Hum Mutat ; 16(2): 143-56, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10923036

RESUMO

We have collated the results of cystic fibrosis (CF) mutation analysis conducted in 19 laboratories in France. We have analyzed 7, 420 CF alleles, demonstrating a total of 310 different mutations including 24 not reported previously, accounting for 93.56% of CF genes. The most common were F508del (67.18%; range 61-80), G542X (2.86%; range 1-6.7%), N1303K (2.10%; range 0.75-4.6%), and 1717-1G>A (1.31%; range 0-2.8%). Only 11 mutations had relative frequencies >0. 4%, 140 mutations were found on a small number of CF alleles (from 29 to two), and 154 were unique. These data show a clear geographical and/or ethnic variation in the distribution of the most common CF mutations. This spectrum of CF mutations, the largest ever reported in one country, has generated 481 different genotypes. We also investigated a cohort of 800 French men with congenital bilateral absence of the vas deferens (CBAVD) and identified a total of 137 different CFTR mutations. Screening for the most common CF defects in addition to assessment for IVS8-5T allowed us to detect two mutations in 47.63% and one in 24.63% of CBAVD patients. In a subset of 327 CBAVD men who were more extensively investigated through the scanning of coding/flanking sequences, 516 of 654 (78. 90%) alleles were identified, with 15.90% and 70.95% of patients carrying one or two mutations, respectively, and only 13.15% without any detectable CFTR abnormality. The distribution of genotypes, classified according to the expected effect of their mutations on CFTR protein, clearly differed between both populations. CF patients had two severe mutations (87.77%) or one severe and one mild/variable mutation (11.33%), whereas CBAVD men had either a severe and a mild/variable (87.89%) or two mild/variable (11.57%) mutations.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/epidemiologia , Fibrose Cística/genética , Mutação/genética , Ducto Deferente/anormalidades , Adulto , Alelos , Deleção Cromossômica , Mutação da Fase de Leitura/genética , França/epidemiologia , Frequência do Gene , Genótipo , Humanos , Infertilidade Masculina/epidemiologia , Infertilidade Masculina/genética , Masculino , Pessoa de Meia-Idade , Mutagênese Insercional/genética , Mutação de Sentido Incorreto/genética , Polimorfismo Genético/genética
13.
Eur J Hum Genet ; 8(3): 229-35, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10780790

RESUMO

Charcot-Marie-Tooth disease, type 1A (CMT1A) is caused in most cases by a 1.5 Mb duplication on chromosome 17p11.2 arising after unequal crossing-over between repeated sequences called CMT1A-REPs, flanking the 1.5 Mb unit. A 3.2 kb recombination hot spot has been defined, resulting in a junction fragment between EcoRI (distal CMT1A-REP) and SacI (proximal CMT1A-REP). This was further reduced to a 1.7kb EcoRI-NsiI fragment, and recently to a 731 bp hot spot region within this fragment. We describe the CMT1A-REPs-based PCR method used to identify CMT1A duplications and report on a family case in which a 29-year-old pregnant woman requested prenatal diagnosis for two successive pregnancies because her husband was affected with CMT1A. Our method enabled us to characterise the duplication in both foetuses and demonstrate that it arose from a rare recombination event taking place outside the 1.7 kb region. Since our approach is simple and enables the entire set of duplications occurring after recombination in the enlarged 3.2kb region including the hot spot to be detected, we suggest it might be considered for use in primary screening for pre- and postnatal diagnosis of CMT1A.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Cromossomos Humanos Par 17 , Doenças Fetais/genética , Duplicação Gênica , Doença de Charcot-Marie-Tooth/diagnóstico , Doença de Charcot-Marie-Tooth/embriologia , Mapeamento Cromossômico , Feminino , Doenças Fetais/diagnóstico , Humanos , Repetições de Microssatélites/genética , Reação em Cadeia da Polimerase/métodos , Gravidez , Diagnóstico Pré-Natal , Recombinação Genética
14.
Horm Res ; 53(6): 279-87, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11146368

RESUMO

We report on the auxological and endocrine evolution of 28 patients presenting with Prader-Willi syndrome. Half of them received growth hormone (GH) therapy (group 2). The spontaneous auxological evolution was analyzed in the two groups from 2 to 8 years; the mean SDS for height remained stable (-0.6 +/- 0.6) in group 1 and decreased (from -2.0 +/- 0.9 to -2.7 +/- 0.6) in group 2. Magnetic resonance imaging showed marked pituitary hypoplasia in the two groups. In group 2, the mean GH peak after two provocative tests was 3.8 +/- 2.4 microg/l, the mean SDS values for insulin-like growth factor I levels were -2.0 +/- 1.5 (range from -0.5 to -5.0). The mean duration of GH treatment was 3.6 +/- 2.9 (range 1-9.3) years. 14 children completed 1 year of treatment. The two groups had opposite evolutions in Delta SDS for height (-0.8 +/- 0.8 vs. +1.1 +/- 0.8), for growth velocity (-1.9 +/- 2.2 vs. +2.9 +/- 2.7), and for Z score of the body mass index (+0.37 +/- 1.3 vs. -0.14 +/- 0.76; group 1 vs. group 2). This retrospective study shows that, in children with Prader-Willi syndrome and true GH deficiency, long-term GH therapy is effective in increasing growth velocity and in maintaining body mass index.


Assuntos
Hormônio do Crescimento Humano/uso terapêutico , Síndrome de Prader-Willi/tratamento farmacológico , Adolescente , Adulto , Estatura , Índice de Massa Corporal , Criança , Pré-Escolar , Criptorquidismo/complicações , Criptorquidismo/diagnóstico , Feminino , Hormônio do Crescimento Humano/sangue , Humanos , Hiperinsulinismo/complicações , Hiperinsulinismo/diagnóstico , Hipotireoidismo/complicações , Hipotireoidismo/diagnóstico , Lactente , Fator de Crescimento Insulin-Like I/análise , Imageamento por Ressonância Magnética , Masculino , Hipófise/patologia , Síndrome de Prader-Willi/complicações , Síndrome de Prader-Willi/fisiopatologia , Puberdade , Estudos Retrospectivos , Resultado do Tratamento
15.
J Med Genet ; 36(7): 554-60, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10424818

RESUMO

Angelman syndrome (AS) is a neurological disorder with a heterogeneous genetic aetiology. It most frequently results from a de novo interstitial deletion in the 15q11-q13 region, but in a few cases it is caused by paternal uniparental disomy (UPD) or an imprinting mutation. The remaining 20 to 30% of AS patients exhibit biparental inheritance and a normal pattern of allelic methylation in the 15q11-q13 region. In this latter group, mutations in the UBE3A gene have recently been shown to be a cause of AS. Here we describe the phenotypic expression in 14 AS cases involving eight UBE3A mutations. These comprise 11 familial cases from five families and three sporadic cases. Subtle differences from the typical phenotype of AS were found. Consistent manifestations were psychomotor delay, a happy disposition, a hyperexcitable personality, EEG abnormalities, and mental retardation with severe speech impairment. The other main manifestations of AS, ataxia, epilepsy, and microcephaly, were either milder or absent in various combinations among the patients. In addition, myoclonus of cortical origin was frequently observed with severe fits inducing myoclonic seizures. The majority of the patients were overweight. This study showed that ataxia, myoclonus, EEG abnormalities, speech impairment, characteristic behavioural phenotype, and abnormal head circumference are attributable to a deficiency in the maternally inherited UBE3A allele. Furthermore, analysis of mutation transmission showed an unexpectedly high rate of somatic mosaicism in normal carriers. These data have important consequences for genetic counselling.


Assuntos
Síndrome de Angelman/genética , Cromossomos Humanos Par 15 , Aconselhamento Genético , Ligases/genética , Mutação , Adolescente , Adulto , Criança , Eletroencefalografia , Feminino , Humanos , Masculino , Mosaicismo/genética , Mutagênese Insercional , Fases de Leitura Aberta , Linhagem , Polimorfismo Conformacional de Fita Simples , Deleção de Sequência , Ubiquitina-Proteína Ligases
16.
Eur J Hum Genet ; 7(2): 131-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10196695

RESUMO

Angelman syndrome (AS) is a neurodevelopmental disorder caused by the absence of a maternal contribution to chromosome 15q11-q13. There are four classes of AS according to molecular or cytogenetic status: maternal microdeletion of 15q11-q13 (approximately 70% of AS patients); uniparental disomy (UPD); defects in a putative imprinting centre (IM); the fourth includes 20-30% of AS individuals with biparental inheritance and a normal pattern of allelic methylation in 15q11-q13. Mutations of UBE3A have recently been identified as causing AS in the latter group. Few studies have investigated the phenotypic differences between these classes. We compared 20 non-deletion to 20 age-matched deletion patients and found significant phenotypic differences between the two groups. The more severe phenotype in the deletion group may suggest a contiguous gene syndrome.


Assuntos
Síndrome de Angelman/genética , Síndrome de Angelman/fisiopatologia , Adolescente , Adulto , Idade de Início , Estatura , Peso Corporal , Criança , Pré-Escolar , Comunicação , Epilepsia , Genótipo , Humanos , Desenvolvimento da Linguagem , Masculino , Fenótipo , Caminhada
17.
Neuromuscul Disord ; 9(1): 3-10, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10063829

RESUMO

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disorder for which no candidate gene has yet been identified. The gene corresponding to one of the novel human cDNAs that we cloned on the basis of a muscle restricted expression pattern [Piétu G, Alibert O, Guichard B, et al. Genome Res 1996;6:492-503] was mapped in the region of the FSHD1A genetic locus, i.e. one of the loci involved in this muscular dystrophy. The corresponding encoded protein contains a PDZ and a LIM domain, two protein-protein interaction domains, and was very recently shown to bind alpha-actinin-2 and was named ALP (actinin-associated LIM protein) [Xia H, Winokur S, Kuo W, Altherr M, Bredt D. J Cell Biol 1997;139:507-515]. We raised a specific polyclonal anti-ALP serum against an ALP recombinant polypeptide to evaluate the size, level of expression and subcellular localization of ALP in three patients, clearly diagnosed with FSHD disease. Quantitative or qualitative alterations of ALP expression have not been detected in any of them, thus prompting us to exclude ALP as a FSHD gene candidate.


Assuntos
Actinina/genética , DNA/genética , Proteínas dos Microfilamentos/genética , Distrofias Musculares/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , Western Blotting , Mapeamento Cromossômico , Clonagem Molecular , Humanos , Proteínas com Domínio LIM , Pessoa de Meia-Idade , Dados de Sequência Molecular , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/ultraestrutura , Distrofias Musculares/metabolismo , Mapeamento por Restrição , Frações Subcelulares/metabolismo , Frações Subcelulares/ultraestrutura , Sequências de Repetição em Tandem/genética
19.
Am J Hum Genet ; 62(6): 1353-60, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9585605

RESUMO

Angelman syndrome (AS) is caused by chromosome 15q11-q13 deletions of maternal origin, by paternal uniparental disomy (UPD) 15, by imprinting defects, and by mutations in the UBE3A gene. UBE3A encodes a ubiquitin-protein ligase and shows brain-specific imprinting. Here we describe UBE3A coding-region mutations detected by SSCP analysis in 13 AS individuals or families. Two identical de novo 5-bp duplications in exon 16 were found. Among the other 11 unique mutations, 8 were small deletions or insertions predicted to cause frameshifts, 1 was a mutation to a stop codon, 1 was a missense mutation, and 1 was predicted to cause insertion of an isoleucine in the hect domain of the UBE3A protein, which functions in E2 binding and ubiquitin transfer. Eight of the cases were familial, and five were sporadic. In two familial cases and one sporadic case, mosaicism for UBE3A mutations was detected: in the mother of three AS sons, in the maternal grandfather of two AS first cousins, and in the mother of an AS daughter. The frequencies with which we detected mutations were 5 (14%) of 35 in sporadic cases and 8 (80%) of 10 in familial cases.


Assuntos
Síndrome de Angelman/genética , Ligases/genética , Mutação , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Mosaicismo , Linhagem , Polimorfismo Conformacional de Fita Simples , Ubiquitina-Proteína Ligases , Ubiquitinas
20.
Nat Genet ; 17(3): 357-61, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9354807

RESUMO

Prader-Willi syndrome (PWS) is a neurogenetic disorder that results from the absence of a normal paternal contribution to the 15q11-13 region. The clinical manifestations of PWS are a transient severe hypotonia in the newborn period, with mental retardation, hypogonadism and obesity observed later in development. Five transcripts with exclusive expression from the paternal allele have been isolated, but none of these has been shown to be involved in PWS. In this study, we report the isolation and characterization of NDN, a new human imprinted gene. NDN is exclusively expressed from the paternal allele in the tissues analysed and is located in the PWS region. It encodes a putative protein homologous to the mouse brain-specific NECDIN protein, NDN; as in mouse, expression in brain is restricted to post-mitotic neurons. NDN displays several characteristics of an imprinted locus, including allelic DNA methylation and asynchronous DNA replication. A complete lack of NDN expression in PWS brain and fibroblasts indicates that the gene is expressed exclusively from the paternal allele in these tissues and suggests a possible role of this new gene in PWS.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Impressão Genômica , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Síndrome de Prader-Willi/genética , Síndrome de Angelman/genética , Animais , Northern Blotting , Mapeamento Cromossômico , Cromossomos Humanos Par 15 , Metilação de DNA , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Feminino , Humanos , Hibridização In Situ/métodos , Hibridização in Situ Fluorescente , Masculino , Camundongos , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/metabolismo , Fenômenos Fisiológicos do Sistema Nervoso , Proteínas Nucleares/metabolismo , Distribuição Tecidual
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