Assuntos
Anormalidades Múltiplas/genética , Aneuploidia , Cromossomos Humanos Par 1/genética , Deficiências do Desenvolvimento/genética , Mosaicismo/genética , Dissomia Uniparental/genética , Adulto , Alelos , Criança , Bandeamento Cromossômico , Feminino , Marcadores Genéticos/genética , Humanos , Hibridização in Situ Fluorescente , Recém-Nascido , Deficiência Intelectual/genética , Cariotipagem , Linfócitos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Cromossomos em AnelRESUMO
Double color in situ hybridization was used to determine the specificity of cloned alpha-satellite cosmid DNA sequences belonging to satellite DNA sequences shared by chromosomes 13 and 21. It was determined that cosmid clone cos56D8 is more specific to chromosome 13, cosmid clone cos37E is more specific to chromosome 21 and cosmid clones cosA5130 is specific to both chromosomes 13 and 21. These new cosmid probes could bw useful in the molecular-cytogenetic analysis of trisomic cells at Patau or Down syndromes as well as in analysis of marker chromosomes originated from the chromosomes 13 and 21.
Assuntos
Cromossomos Humanos Par 13/genética , Cromossomos Humanos Par 21/genética , Cosmídeos/genética , DNA Satélite/genética , Hibridização in Situ Fluorescente/métodos , Células Cultivadas , Clonagem Molecular , Cor , Sondas de DNA , Humanos , Interfase/genética , Metáfase/genéticaRESUMO
Genomic imprinting of chromosome arm 11p is involved in the Wiedemann-Beckwith syndrome (WBS). About 20% of patients with sporadic WBS have paternal uniparental disomy (UPD) of 11p. Mitotic recombination at the 11p region has been suggested to be responsible for the somatic mosaicism in these patients. Our current study concerning sporadic WBS patients demonstrated six patients with mosaic isodisomy restricted to part of 11p and one patient with mosaic paternal uniparental disomy for the whole chromosome 11. Apparently the clinical findings for this patient did not differ from data reported for other WBS patients. This case makes it unlikely that the proximal short arm and the long arm of chromosome 11 contain imprinted genes with a phenotype recognizable prenatally or in infancy, and gives some support to the hypothesis that non-mosaic UPD-11 is prenatally lethal.
Assuntos
Síndrome de Beckwith-Wiedemann/genética , Cromossomos Humanos Par 11/genética , Impressão Genômica/genética , Mosaicismo/genética , RNA não Traduzido , Síndrome de Beckwith-Wiedemann/patologia , Southern Blotting , Criança , Pré-Escolar , DNA/análise , Feminino , Genes Supressores de Tumor/genética , Marcadores Genéticos , Humanos , Lactente , Masculino , Proteínas Musculares/genética , Linhagem , Regiões Promotoras Genéticas/genética , RNA Longo não CodificanteRESUMO
Four cases of patients with additional marker chromosomes are described. The clinical, cytogenetic and molecular cytogenetic methods have been used for investigation. The identification of marker chromosomes was made by using in situ hybridization and the collection of chromosome-specific DNA probes. All marker chromosomes were determined as originated from chromosome 21 with break-points in the region between 21q11 and 21q22.
Assuntos
Cromossomos Humanos Par 21/genética , Hibridização In Situ , Aberrações Cromossômicas/genética , Bandeamento Cromossômico , Sondas de DNA , Síndrome de Down/genética , Feminino , Marcadores Genéticos/genética , Heterozigoto , Humanos , Masculino , FenótipoRESUMO
Nine additional marker chromosomes in children with mental retardation and congenital malformation were investigated by routine cytogenetic and in situ hybridization techniques. Five metacentric non-satellited markers and four satellited markers of unknown origin were determined by routine and banding staining. To determine the origin of small marker chromosomes a special scheme involving the sequential application of definite alphoid and "classical" satellite DNA probes with the relative chromosome specificity was employed. The probes specific to four groups of definite chromosomes (i) 1, 3, 5, 6, 7, 10, 12, 16, 19; (ii) 2, 4, 8, 9, 13, 14, 15, 18, 20, 21, 22; (iii) 1, 11, 17, X; (iiii) 9, 13, 14, 15, 21, 22, Y and in situ hybridization under low stringency conditions were used at the first stage of experiments. After the preliminary analysis and the determination of possible origin of a marker chromosome from a definite group of chromosomes the probes with a strong chromosome-specificity under high stringency conditions were used. The approach involving the application of the original collection of chromosome-specific DNA probes, including molecular markers to practically all human chromosomes [1, 2], and various conditions of hybridization provides an effective method for detecting unknown markers. Marker chromosomes investigated in this study were derivatives of chromosomes 7, 9 (two cases), 13, 14, 21 (two cases), X and Y.
