RESUMEN
The NOTCH4 gene was recently reported to be associated with schizophrenia based on TDT analysis of 80 British trios. The strongest evidence for association derived from two microsatellites. We genotyped both loci in a large sample of unrelated Scottish schizophrenics and controls, but failed to replicate the reported association, finding instead that each putative schizophrenia-associated allele had a somewhat lower frequency in schizophrenics than in controls.
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Proteínas Proto-Oncogénicas/genética , Receptores de Superficie Celular , Esquizofrenia/genética , Alelos , Estudios de Casos y Controles , Genética de Población , Humanos , Repeticiones de Microsatélite , Receptor Notch4 , Receptores Notch , EscociaRESUMEN
The development of detailed single nucleotide polymorphism (SNP) maps of the human genome coupled with high-throughput genotyping technologies may allow us to unravel complex genetic traits, such as multifactorial disease or drug response, over the next few years. Here we describe the current efforts to identify and characterize the large numbers of SNPs required and discuss the practicalities of association studies for the identification of genes involved in complex traits.
Asunto(s)
Polimorfismo de Nucleótido Simple , Genética Médica , Genoma Humano , Genotipo , HumanosRESUMEN
As the human genome project approaches completion, the challenge for mammalian geneticists is to develop approaches for the systematic determination of mammalian gene function. Mouse mutagenesis will be a key element of studies of gene function. Phenotype-driven approaches using the chemical mutagen ethylnitrosourea (ENU) represent a potentially efficient route for the generation of large numbers of mutant mice that can be screened for novel phenotypes. The advantage of this approach is that, in assessing gene function, no a priori assumptions are made about the genes involved in any pathway. Phenotype-driven mutagenesis is thus an effective method for the identification of novel genes and pathways. We have undertaken a genome-wide, phenotype-driven screen for dominant mutations in the mouse. We generated and screened over 26,000 mice, and recovered some 500 new mouse mutants. Our work, along with the programme reported in the accompanying paper, has led to a substantial increase in the mouse mutant resource and represents a first step towards systematic studies of gene function in mammalian genetics.
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Genes/fisiología , Genoma , Mutagénesis/genética , Animales , Animales Recién Nacidos , Mapeo Cromosómico , Cruzamientos Genéticos , Criopreservación , Etilnitrosourea/farmacología , Femenino , Fertilización In Vitro , Genes/efectos de los fármacos , Genes/genética , Pruebas Hematológicas , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Actividad Motora/genética , Mutagénesis/efectos de los fármacos , Mutágenos/farmacología , Mutación , Fenotipo , Factores de Tiempo , DesteteRESUMEN
Mouse mutants have a key role in discerning mammalian gene function and modelling human disease; however, at present mutants exist for only 1-2% of all mouse genes. In order to address this phenotype gap, we have embarked on a genome-wide, phenotype-driven, large-scale N-ethyl-N--nitrosourea (ENU) mutagenesis screen for dominant mutations of clinical and pharmacological interest in the mouse. Here we describe the identification of two similar neurological phenotypes and determination of the underlying mutations using a novel rapid mapping strategy incorporating speed back-crosses and high throughput genotyping. Two mutant mice were identified with marked resting tremor and further characterized using the SHIRPA behavioural and functional assessment protocol. Back-cross animals were generated using in vitro fertilization and genome scans performed utilizing DNA pools derived from multiple mutant mice. Both mutants were mapped to a region on chromosome 11 containing the peripheral myelin protein 22 gene (Pmp22). Sequence analysis revealed novel point mutations in Pmp22 in both lines. The first mutation, H12R, alters the same amino acid as in the severe human peripheral neuropathy Dejerine Sottas syndrome and Y153TER in the other mutant truncates the Pmp22 protein by seven amino acids. Histological analysis of both lines revealed hypo-myelination of peripheral nerves. This is the first report of the generation of a clinically relevant neurological mutant and its rapid genetic characterization from a large-scale mutagenesis screen for dominant phenotypes in the mouse, and validates the use of large-scale screens to generate desired clinical phenotypes in mice.
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Proteínas de la Mielina/genética , Animales , Mapeo Cromosómico , Femenino , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones Mutantes , Mutagénesis , Vaina de Mielina/metabolismo , Fenotipo , Factores de TiempoRESUMEN
PTEN, a putative tumour suppressor gene associated with prostate and other cancers, is known to be located within the chromosomal region 10q23.3. Transcription of the PTEN gives rise to multiple mRNA species. Analyses by Northern blots, using cell lines which express PTEN together with cell lines which have lost the PTEN or carry a truncated version of the gene, has allowed us to demonstrate that the pseudogene is not transcribed. In addition, 3' RACE studies confirmed that the multiple mRNA species arising from the gene probably result from the use of alternative polyadenylation sites. No evidence for tissue- or cell-specific patterns of transcription was found. Analysis by 5' RACE placed the putative site for the start of transcription around 830 bp upstream of the start codon. A map of the location of the PTEN gene with a series of overlapping YAC, BAC and PACs has been constructed and the relative position of eight microsatellite markers sited. Two known and one novel marker have been positioned within the gene, the others are in flanking regions. The more accurate location of these markers should help in future studies of the extent of gene loss. Several polymorphisms were also identified, all were within introns. Four of the common polymorphisms appear to be linked. In blood, DNA from 200 individuals, including normal, BPH and prostate cancer patients, confirmed this link. Only two samples of 200 did not carry the linked haplotype, both were patients with advanced prostate cancer. It is possible that such rearrangements within PTEN could be evidence of predisposition to prostate cancer in this small number of cases.
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Cromosomas Humanos Par 10/genética , Genes Supresores de Tumor/genética , Pérdida de Heterocigocidad , Monoéster Fosfórico Hidrolasas/genética , Polimorfismo Genético , Proteínas Supresoras de Tumor , Empalme Alternativo , Northern Blotting , Mapeo Cromosómico/métodos , Cromosomas Artificiales de Levadura/genética , Cromosomas Bacterianos/genética , Marcadores Genéticos , Humanos , Repeticiones de Microsatélite/genética , Fosfohidrolasa PTEN , ARN Mensajero/genética , Células Tumorales CultivadasRESUMEN
The chromosomal region 10q23-24 is frequently deleted in a number of tumour types, including prostate adenocarcinoma and glioma. A candidate tumour-suppressor gene at 10q23.3, designated PTENor MMAC1, with putative actin-binding and tyrosine phosphatase domains has recently been described. Mutations in PTEN have been identified in cell lines derived from gliomas, melanomas and prostate tumours and from a number of tumour specimens derived from glial, breast, endometrial and kidney tissue. Germline mutations in PTEN appear to be responsible for Cowden disease. We identified five PTEN mutations in 37 primary prostatic tumours analysed and found that 70% of tumours showed loss or alteration of at least one PTEN allele, supporting the evidence for PTEN involvement in prostate tumour progression. We raised antisera to a peptide from PTEN and showed that reactivity occurs in numerous small cytoplasmic organelles and that the protein is commonly expressed in a variety of cell types. Northern blot analysis revealed multiple RNA species; some arise as a result of alternative polyadenylation sites, but others may be due to alternative splicing.
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ADN de Neoplasias/genética , Regulación Neoplásica de la Expresión Génica , Genes Supresores de Tumor , Monoéster Fosfórico Hidrolasas/genética , Neoplasias de la Próstata/genética , Proteínas Supresoras de Tumor , Secuencia de Aminoácidos , Northern Blotting , Análisis Mutacional de ADN , Humanos , Masculino , Datos de Secuencia Molecular , Fosfohidrolasa PTEN , ARN Neoplásico/análisisAsunto(s)
Mapeo Cromosómico/métodos , Cromosomas Humanos Par 10/genética , Enfermedades del Sistema Nervioso/genética , Cromosomas Artificiales de Levadura/genética , Epilepsias Parciales/genética , Etiquetas de Secuencia Expresada , Cara/anomalías , Ligamiento Genético , Humanos , Repeticiones de Microsatélite , Mapeo Físico de Cromosoma , Mapeo Restrictivo , Degeneraciones Espinocerebelosas/genética , Síndrome , Vejiga Urinaria Neurogénica/genéticaRESUMEN
Rearrangement of distal 10q is a common feature of many tumor types and tumor-derived cell lines. More specifically, loss of 10q23-25 has been demonstrated in a large proportion of prostate tumors, indicative of the presence of a tumor suppressor gene at this location. Using whole-chromosome paints and human genomic YAC clones as FISH probes, we have performed a detailed cytogenetic analysis of distal 10q rearrangements in the prostate adenocarcinoma cell line LNCaP. Our data reveal nonreciprocal translocation of 10q24.1-qter material to two sites on chromosome 5q, giving der(5)t(5;10) (q14-23;q24.1)t(5;10)(q35;q24.2) loss of 10q material at the 10q24.1 breakpoint. Deleted chromatin at the distal breakpoint includes the cytochrome P450IIC (CYP2C) gene cluster, thought to be involved in steroid hormone metabolism and therefore of possible significance to the growth rate of this androgen-dependent cell line. Deleted material at the proximal breakpoint overlaps with a region of deletion at the 10q23-24 boundary recently identified in a high proportion of prostate tumors, adding to the evidence for a tumor suppressor gene in this interval.
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Adenocarcinoma/genética , Deleción Cromosómica , Cromosomas Humanos Par 10 , Neoplasias de la Próstata/genética , Translocación Genética , Línea Celular , Humanos , Hibridación Fluorescente in Situ , MasculinoRESUMEN
The distal long arm of chromosome 10 harbors genes of biomedical interest such as MXI1, a putative tumor suppressor gene, and those encoding the adrenergic receptors alpha2A (ADRA2A) and beta1 (ADRB1). As part of a physical and genetic study of this genomic region, we constructed a 1.5-Mb YAC contig mapping to 10q25 that contains MXI1 and ADRA2A as well as a number of STSs. Rare cutting restriction site analysis of overlapping YACs allowed fine mapping of these genes and markers along the contig and revealed the presence of four CpG islands. MXI1 and ADRA2A appear to be about 600 kb apart, whereas ADRB1 is separated from ADRA2A by a distance larger than previously reported.
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Proteínas de Unión al ADN/genética , Receptores Adrenérgicos alfa 2/genética , Factores de Transcripción/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Mapeo Cromosómico , Cromosomas Artificiales de Levadura/genética , Cromosomas Humanos Par 10/genética , Islas de CpG , Genes Supresores de Tumor , Marcadores Genéticos , Humanos , Hibridación Fluorescente in Situ , Mapeo Restrictivo , Lugares Marcados de Secuencia , Proteínas Supresoras de TumorRESUMEN
Chromosome band 10q24 is rich in genes involved in development, tumorigenesis, neurological disorders, hormone metabolism, and environmentally induced disease susceptibility. We have constructed an STS-based integrated physical and genetic map of 10q24 derived from the CEPH-Généthon mega-YAC contig data for this region. This map consists of 42 fluorescence in situ hybridization-mapped overlapping CEPH mega-YACs spanning approximately 15 Mb to which 49 STS markers have been assigned, including 24 Généthon CA repeat genetic markers, 10 known gene loci from the 10q24 region (IFI56, IDE, PDE6C, RBP4, CYP2C, CD39, DNTT, GOT1, WNT8B, and PAX2) and 11 additional expressed sequences of unknown function.
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Mapeo Cromosómico , Cromosomas Humanos Par 10/genética , Bandeo Cromosómico , Cromosomas Artificiales de Levadura , Repeticiones de Dinucleótido , Marcadores Genéticos , Humanos , Lugares Marcados de SecuenciaRESUMEN
Breast cancer in men is rare and is clearly due in some cases to an inherited predisposition. A total of 28 male breast cancer patients were tested for BRCA2 mutations; two frameshifts and one putative missense mutation were identified. One of the frameshifts was detected in the same position as a mutation estimated to be responsible for 40% of all male breast cancer cases in Iceland.
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Neoplasias de la Mama Masculina/genética , Mutación de Línea Germinal , Proteínas de Neoplasias/genética , Factores de Transcripción/genética , Proteína BRCA2 , Secuencia de Bases , Neoplasias de la Mama/genética , ADN de Neoplasias/análisis , ADN de Neoplasias/genética , Femenino , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-SimpleRESUMEN
Loss of the chromosomal region 10q23-25 is a frequent event in the progression of prostate adenocarcinoma. A candidate tumor suppressor gene from this region, Mxi1 at 10q25, has recently been shown to be mutated in a small number of prostate tumors. To more strictly define those regions of 10q loss that are likely to be involved in tumor advancement, we have constructed a detailed deletion map spanning 10q23-25 that incorporates Mxi1. Sixty-two % (23 of 37) of tumors analyzed exhibited some degree of 10q23-25 loss. Our data suggest the presence of a prostate tumor suppressor gene(s) near the 10q23-24 boundary, which was deleted in the overwhelming majority (22 of 23) of tumors showing loss. In contrast, specific loss of Mxi1, as opposed to loss of other 10q23-25 regions or of the entire region, was observed in only 1 of 23 tumors and was accompanied by loss of markers at the 10q23-24 boundary. Furthermore, we failed to detect any mutations in Mxi1 in those tumors showing Mxi1-associated marker loss by either single-strand conformation polymorphism analysis or direct DNA sequencing.
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Deleción Cromosómica , Cromosomas Humanos Par 10/genética , Neoplasias de la Próstata/genética , Factores de Transcripción , Anciano , Anciano de 80 o más Años , Alelos , Secuencia de Bases , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Mapeo Cromosómico , ADN de Neoplasias/análisis , ADN de Neoplasias/genética , ADN Satélite/análisis , ADN Satélite/genética , Proteínas de Unión al ADN/genética , Fluorescencia , Genes Supresores de Tumor , Marcadores Genéticos , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Mutación , Estadificación de Neoplasias , Neoplasias de la Próstata/patología , Proteínas Supresoras de TumorRESUMEN
The CYP2C gene cluster on chromosome 10q24 encodes the P450IIC enzymes, members of the cytochrome P450 monooxygenase superfamily. The P450-IIC enzymes are required for the metabolism of a number of foreign compounds, including the drugs mephenytoin and tolbutamide, and are also thought to be involved in the metabolism of endogenous steroid hormones. Several different CYP2C cDNA clones have been isolated; however, the exact number of genes and the genomic arrangement of the CYP2C cluster have remained unknown. Using a combination of STS and restriction mapping to characterize YAC clones, we have constructed a 2.4-Mb physical map that incorporates the CYP2C gene cluster. The cluster spans approximately 500 kb on proximal 10q24 and comprises four genes arranged in the order CYP2C8-CYP2C9-CYP2C19-CYP2C18. The map also includes an adjacent gene, the serum retinol binding protein gene (RBP4). The incorporation of Généthon CA repeat genetic markers suggests the orientation of the loci to be Cen-RBP4-CYP2C18-CYP2C19-CYP2C9-CYP2C8-Tel .
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Hidrocarburo de Aril Hidroxilasas , Mapeo Cromosómico , Cromosomas Humanos Par 10 , Sistema Enzimático del Citocromo P-450/genética , Esteroide 16-alfa-Hidroxilasa , Esteroide Hidroxilasas/genética , Secuencia de Bases , Citocromo P-450 CYP2C8 , Citocromo P-450 CYP2C9 , Genes , Humanos , Datos de Secuencia Molecular , Familia de Multigenes , Proteínas de Unión al Retinol/genética , Lugares Marcados de SecuenciaRESUMEN
We have reviewed the results in 34 patients (39 operations) following simple excision of the trapezium for osteoarthritis of the basal joint of the thumb. The average age at operation was 57 years and the average follow-up was 6 years. All the patients were graded clinically and radiologically and were asked their opinion of the procedure. There was dramatic relief of pain following this procedure. Stability of the thumb was not compromised. When compared to the unoperated side, thumb length, thumb abduction and first web span were similar. There was a reduction in pinch strength (operated 8.1 k.p.a., non-operated 9.6 k.p.a.) and grip strength (operated 15.5 k.p.a., non-operated 19.5 k.p.a.) and an increase in MIP extension (operated 5.4 degrees, non-operated 2.9 degrees) following this procedure but the differences were not statistically significant. 11 patients (32%) had scar hyperaesthesia on testing but this was a clinical problem in two patients only (5%). Simple excision of the trapezium is a satisfactory procedure for the majority of patients with this disorder, but has a long post-operative rehabilitation period.
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Huesos del Carpo/cirugía , Articulaciones/cirugía , Metacarpo/cirugía , Osteoartritis/cirugía , Pulgar/cirugía , Anciano , Cicatriz/patología , Femenino , Estudios de Seguimiento , Humanos , Hipoestesia/fisiopatología , Articulaciones/patología , Articulaciones/fisiopatología , Masculino , Articulación Metacarpofalángica/fisiopatología , Persona de Mediana Edad , Rango del Movimiento Articular/fisiología , Estrés Mecánico , Pulgar/patología , Pulgar/fisiopatologíaRESUMEN
There is considerable anthropological and forensic interest in the possibility of DNA typing skeletal remains. Trace amounts of DNA can be recovered even from 5,500-year-old bones and multicopy human mitochondrial DNA sequences can frequently be amplified from such DNA using the polymerase chain reaction (PCR). But given the sensitivity of PCR, it is very difficult to exclude contaminating material. We now report the successful identification of the 8-year-old skeletal remains of a murder victim, by comparative typing of nuclear microsatellite markers in the remains and in the presumptive parents of the victim. This analysis establishes the authenticity of the bone DNA and the feasibility of bone DNA typing in forensic investigations.
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Huesos/química , ADN/análisis , Medicina Legal , Homicidio , Adolescente , Secuencia de Bases , ADN/genética , Padre , Femenino , Genotipo , Humanos , Datos de Secuencia Molecular , Madres , Desnaturalización de Ácido Nucleico , Hibridación de Ácido Nucleico , Reacción en Cadena de la Polimerasa , GalesRESUMEN
Using PCR, two minisatellite loci showing extreme repeat-unit copy-number variation in humans have been characterized in great apes and monkeys. In contrast to humans, minisatellite locus MS32 is monomorphic with only 3-4 diverged repeat units in great apes, Old World and New World monkeys, this organization presumably representing the relatively stable ancestral precursor state of the human hypervariable locus. Similarly, minisatellite MS1 shows extreme repeat-copy-number variability in man compared with low copy number and minimal variability in great apes. Analysis of variant repeat units shows that the 5' and 3' regions of MS1 are relatively stable in great apes and man, and that variability in man is confined to the central region of the minisatellite. In contrast to the great apes, MS1 is highly variable in Old World monkeys. These results, as well as computer simulations of minisatellite evolution based on known mutation rates, show that short minisatellites are stable within the genome, and that the degree of polymorphism at a given locus can change dramatically over a short period of evolutionary time. The ability of hypervariable minisatellites to detect highly informative loci by cross-species hybridization is therefore largely unpredictable.
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Evolución Biológica , ADN Satélite/genética , Animales , Secuencia de Bases , Humanos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Primates , Secuencias Repetitivas de Ácidos Nucleicos , Homología de Secuencia de Ácido Nucleico , Especificidad de la EspecieRESUMEN
Since 1985, DNA typing systems have played an increasingly important role in many aspects of human genetics, most notably in forensic and legal medicine. This article reviews the development of multilocus and single locus minisatellite DNA probes, and more recently the use of PCR to amplify hypervariable DNA loci, as well as discussing the biological properties of the unstable regions of DNA which form the basis of almost all DNA fingerprinting systems.
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Dermatoglifia del ADN , Secuencia de Bases , ADN Satélite , Humanos , Datos de Secuencia Molecular , Mutación , Reacción en Cadena de la PolimerasaRESUMEN
The importance of psychologic distress and illness behavior is well recognized in low-back pain but has rarely been studied in other orthopedic conditions. Psychologic and clinical assessment of 100 patients undergoing elective surgery for minor leg conditions or joint replacement for osteoarthritis or rheumatoid arthritis showed surprisingly little psychologic distress or illness behavior, particularly when compared with 235 patients with low-back pain. The most striking finding was that in low-back pain there was a close relation between psychologic disturbance and failed surgery, but the nonspinal patients showed a complete absence of such a relation. This type of psychologic assessment is neither necessary nor helpful in the routine management of most clearly defined, nonspinal, correctly managed orthopedic conditions.
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Dolor de Espalda/psicología , Entrevista Psicológica , Artropatías/psicología , Pruebas Psicológicas , Adulto , Anciano , Femenino , Humanos , Prótesis Articulares , Masculino , Persona de Mediana Edad , Dolor/psicología , Cuidados PreoperatoriosRESUMEN
A case is presented of acute loss of function of flexor pollicis longus and profundus tendon to the index finger. Although the aetiology was obscure, the acute onset suggested a mechanical cause rather than a nerve compression disorder such as anterior interosseous nerve palsy. X-rays showed an ununited scaphoid fracture related to an injury many years previously. Surgical exploration revealed attritional rupture of flexor pollicis longus and partial division of profundus tendon to index finger by a spicule of ununited scaphoid which had eroded through the volar capsule. Removal of the spicule and tenodesis of flexor pollicis longus gave a good long term result.