RESUMO
The frequency distribution of Y-chromosome haplotypes at DNA polymorphism p49/TaqI was studied in a sample of 505 North Africans from Mauritania, Morocco, Algeria, Tunisia, Libya, and Egypt. A particularly high frequency (55.0%) of Y-haplotype 5 (A2, C0, D0, F1, I1) was observed in these populations, with a relative predominance in those of Berber origin. Examination of the relative frequencies of other haplotypes in these populations, mainly haplotype 4 (the "African" haplotype), haplotype 15 (the "European" haplotype), and haplotypes 7 and 8 (the "Near-East" haplotypes), permit useful comparisons with neighboring peoples living in sub-Saharan Africa, Europe, and the Near East.
Assuntos
DNA/genética , Etnicidade/genética , Cromossomo Y/genética , Adulto , África do Norte/epidemiologia , Povo Asiático/genética , População Negra/genética , França/etnologia , Frequência do Gene , Variação Genética , Genética Populacional , Haplótipos/genética , Humanos , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Estudos de Amostragem , População Branca/genéticaRESUMO
We collected 7 Friedreich ataxia (FRDA) pedigrees from France. All cases but one family were homozygous for an unstable GAA trinucleotide expansion in the first intron of the frataxin gene. In this peculiar pedigree absence of the GAA expansion supports the notion of possible genetic heterogeneity of FRDA.
Assuntos
Ataxia de Friedreich/genética , Repetições de Trinucleotídeos/genética , Adulto , Cromossomos Humanos Par 9 , Feminino , França , Marcadores Genéticos , Genoma , Humanos , Masculino , LinhagemRESUMO
DNA samples from Ashkenazic and Sephardic Jews were studied with the Y-chromosome-specific DNA probes p49f and p49a to screen for restriction fragment length polymorphisms and haplotypes. Two haplotypes (VII and VIII) are the most widespread, representing about 50% of the total number of haplotypes in Jews. The major haplotype in Oriental Jews is haplotype VIII (85.1%); haplotype VIII is also the major haplotype in the Djerban Jews (77.5%) (Djerban Jews represent probably one of the oldest Jewish communities). Together these results confirm that haplotype VIII is the ancestral haplotype in Jews.
Assuntos
Sondas de DNA/genética , Judeus/genética , Cromossomo Y/genética , Mapeamento Cromossômico , Sondas de DNA/análise , Haplótipos/genética , HumanosRESUMO
Molecular characterization of Charcot-Marie-Tooth patients in 15 pedigree from France: We collected 15 Charcot-Marie-Tooth (CMT) pedigrees from France. DNA polymorphisms analysis by Southern blotting with probes at the D17S122 locus demonstrated 17p duplication in three CMT1a families and in one sporadic case. Two families affected by CMT2 showed no evidence of the duplication.
Assuntos
Doença de Charcot-Marie-Tooth/genética , Aberrações Cromossômicas/genética , Sondas de DNA , Southern Blotting , Doença de Charcot-Marie-Tooth/classificação , Transtornos Cromossômicos , Cromossomos Humanos Par 17 , Consanguinidade , Feminino , França , Genes Dominantes/genética , Humanos , Masculino , LinhagemRESUMO
Apolipoprotein E, type epsilon 4 allele (ApoE epsilon 4), is associated with late-onset sporadic Alzheimer's disease (AD) in French patients. The association is highly significant (0.45 AD versus 0.12 controls for epsilon 4 allele frequencies). These data support the involvement of ApoE epsilon 4 allele as a very important risk factor for the clinical expression of AD.
Assuntos
Alelos , Doença de Alzheimer/genética , Apolipoproteínas E/genética , Idoso , Sequência de Bases , DNA/análise , Genótipo , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fatores de TempoRESUMO
The results of DNA analysis for the unstable CTG repeat are reported in a french family of myotonic dystrophy. This retrospective study confirms results obtained previously with a linked DNA marker, using the CTG repeat DNA sequence in the same family. The demonstrated possibility of predicting phenotype as well as genotype in prenatal diagnosis is important for such a disorder, were subjects may be severely affected.
Assuntos
Cardiotocografia , Distrofia Miotônica/genética , Diagnóstico Pré-Natal , Adulto , Apolipoproteína C-II , Apolipoproteínas C/genética , Amostra da Vilosidade Coriônica , Sondas de DNA , Feminino , Aconselhamento Genético , Ligação Genética/genética , Marcadores Genéticos/genética , Humanos , Recém-Nascido , Distrofia Miotônica/diagnóstico , Linhagem , Fenótipo , Polimorfismo Genético , Gravidez , Estudos RetrospectivosRESUMO
We describe a polymerase chain reaction (PCR) based on the simultaneous detection of multiple strains of papillomavirus in a single reaction tube. This PCR method was specific and sensitive. We have validated this multiplex procedure on a collection of typed cervical biopsies specimens, and applied it to the detection of viruses in some clinical samples.
Assuntos
DNA Viral/análise , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Reação em Cadeia da Polimerase/métodos , Doenças do Colo do Útero/diagnóstico , Adolescente , Adulto , Sequência de Bases , Colo do Útero/microbiologia , Primers do DNA , Feminino , Humanos , Dados de Sequência Molecular , Papillomaviridae/genética , Sensibilidade e Especificidade , Infecções Tumorais por Vírus/diagnóstico , Esfregaço Vaginal , Displasia do Colo do Útero/diagnósticoAssuntos
Ataxia de Friedreich/genética , Recombinação Genética , Feminino , Humanos , Masculino , LinhagemRESUMO
Portuguese type amyloidosis is an autosomal dominant condition caused by a mutation in the transthyretin gene. This mutation can be detected directly by the presence of a restriction site for NsiI. We report here our first prenatal diagnosis for this condition performed by chorionic villus sampling, polymerase chain reaction, and restriction enzyme digestion.
Assuntos
Neuropatias Amiloides/genética , Diagnóstico Pré-Natal , Neuropatias Amiloides/diagnóstico , Amostra da Vilosidade Coriônica , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Feminino , França , Genes Dominantes/genética , Humanos , Mutação/genética , Reação em Cadeia da Polimerase , Portugal/etnologia , Pré-Albumina/genética , GravidezRESUMO
The presymptomatic diagnosis of Huntington chorea (HC) by genic amplification (PCR: polymerase chain reaction) of a DNA G8 sequence containing a polymorphic HindIII site was tested in a particular HC genealogy. The advantage of this method are discussed.
Assuntos
Doença de Huntington/diagnóstico , Técnicas de Amplificação de Ácido Nucleico , Amplificação de Genes/genética , Humanos , Doença de Huntington/genética , LinhagemRESUMO
Huntington disease (HD) is a neurodegenerative disorder caused by an autosomal dominantly inherited defect. The discovery of DNA polymorphisms genetically linked to the HD locus provided the possibility of an early presymptomatic test. The first marker locus described (G-8) had an approximately 5% recombination rate with the HD locus, and the subsequent discovery of some more tightly linked marker loci, notably D 495, has greatly improved the accuracy of presymptomatic testing. We describe here the preliminary results obtained and the difficulties encountered in a French predictive testing program on presymptomatic subjects belonging to choreic families.
Assuntos
Sondas de DNA , Biblioteca Genômica , Doença de Huntington/genética , Polimorfismo de Fragmento de Restrição , França , Haplótipos , Heterozigoto , Humanos , Linhagem , Fatores de RiscoRESUMO
Linkage analysis was undertaken in seven French families with facioscapulohumeral muscular dystrophy (FSHD). Six polymorphic DNA probes were studied, including random DNA sequences, coding sequences, and a hypervariable marker. No evidence for linkage of these probes to the disease was detected, and the results exclude probable location of the FSHD gene from three chromosomal regions (16p, proximal 19q, and 21q).
Assuntos
Mapeamento Cromossômico , Ligação Genética , Distrofias Musculares/genética , Mapeamento Cromossômico/métodos , Cromossomos Humanos Par 16 , Cromossomos Humanos Par 19 , Cromossomos Humanos Par 21 , Sondas de DNA , Interpretação Estatística de Dados , França , Humanos , Distrofias Musculares/patologiaRESUMO
We analyzed the segregation between fragile site Xq 27 and flanking polymorphic probes (52A, for factor 9, 4D-8, for factor 8, St14 and MN12) in a great Xq-fra pedigree. On the basis of these data, the use of these probes is discussed in view of its value as a diagnostic tool.
Assuntos
Sondas de DNA , Síndrome do Cromossomo X Frágil/diagnóstico , Transtornos Mentais/genética , Aberrações dos Cromossomos Sexuais/diagnóstico , Feminino , Humanos , Masculino , Linhagem , Polimorfismo Genético , Recombinação GenéticaRESUMO
The Y specific probe (two 49f and 49a sub-clones) is a polymorphic one for the A (5 alleles), C (2 alleles), D (3 alleles), F (2 alleles) and I (2 alleles). We show that the corresponding allelic combinations, or haplotypes, are transmitted father-to-son in eleven random chosen families. Utilisation of these polymorphisms in other eleven father-son paternitity cases, studied for a panel of erythrocytic and seric markers, shows a good correlation between the two approaches, most of the paternies excluded by the Y probes being also excluded with other allotypic markers. Utilisation of this sort of polymorphism does not necessitate the knowledge of maternal genotype in families studied.
Assuntos
Sondas de DNA , Paternidade , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , Cromossomo Y , Humanos , LinhagemRESUMO
Segregation studies of X-linked adrenoleukodystrophy (ALD) and a cloned desoxyribonucleic fragment (factor VIII gene), which detects polymorphism in the distal end of the long arm of the X chromosome (Xq28), are reported in a large sibship ALD family. The findings should permit better identification of carriers and add a new marker for identifying the ALD gene itself.