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- Arnell, Henrik, et al.
(författare)
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The genetics of primary nocturnal enuresis: inheritance and suggestion of a second major gene on chromosome 12q
- 1997
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Ingår i: Journal of Medical Genetics. - : BMJ. - 0022-2593 .- 1468-6244. ; 34:5, s. 360-5
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Tidskriftsartikel (refereegranskat)abstract
- Primary nocturnal enuresis (PNE), or bedwetting at night, affects approximately 10% of 6 year old children. Genetic components contribute to the pathogenesis and recently one locus was assigned to chromosome 13q. We evaluated the genetic factors and the pattern of inheritance for PNE in 392 families. Dominant transmission was observed in 43% and an apparent recessive mode of inheritance was observed in 9% of the families. Among the 392 probands the ratio of males to females was 3:1 indicating sex linked or sex influenced factors. Linkage to candidate regions was tested in 16 larger families segregating for autosomal dominant PNE. A gene for PNE was excluded from chromosome 13q in 11 families, whereas linkage to the interval D13S263-D13S291 was suggested (Zmax = 2.1) in three families. Further linkage analyses excluded about 1/3 of the genome at a 10 cM resolution except the region around D12S80 on chromosome 12q that showed a positive two point lod score in six of the families (Zmax = 4.2). This locus remains suggestive because the material was not sufficiently large to give evidence for heterogeneity. Our pedigree analysis indicates that major genes are involved in a large proportion of PNE families and the linkage results suggest that such a gene is located on chromosome 12q.
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| 2. |
- Emahazion, Tesfai
(författare)
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Genomic strategies towards the dissection of human complex disease
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Complex diseases are caused by the activities of many genes acting in concert with environmental factors. A major challenge facing human genetic research is to unravel the genetic factors behind complex disorders. Oxidative damage by free oxygen radicals is believed to contribute to many complex disorders, particularly degenerative disorders such as Alzheimer's disease. A principle source of oxygen free radicals in a human cell is the mitochondrial Oxidative Phosphorylation pathway. This consists of five protein complexes whose subunits are encoded both by the mitochondrial and the nuclear genomes. The least genetically defined complex is Complex I, which comprises 41 genes, of which 34 are encoded by the nuclear genome and the remaining seven by the mitochondrial genome. By exploiting publicly available EST sequences and by radiation hybrid mapping, I successfully characterized and mapped 20 nuclear complex I genes to precise chromosomal locations. These genes can now be tested in positional candidate scenarios. Turning my attention to encephalomyopathies, I analyzed eight patients from Italy suffering severe myopathic disease. All eight individuals had confirmed Oxidative Phosphorylation Complex I biochemical deficiency but did not carry known mitochondrial DNA mutations. We mutation scanned over 20 Complex I cDNAs and found one rare alteration causing the substitution of an evolutionary conserved glycine to arginine at amino acid position 32 in the NDUFA1 gene. The pathogenic role of this mutation is unclear. Polymorphism is an important investigation tool in genetic research, without which disease genes could not be identified. Single nucleotide polymorphisms (SNPs) are one base differences within a population. They have high prevalence in the human genome, are easy to score, and are suitable for automated genotyping techniques. I therefore worked to identify 167 SNPs in 88 candidate genes for neurodegenerative disorders. These SNPs would provide a valuable resource for subsequent association analysis. Alzheimer's disease (AD) is a complex disease where many risk genes have been reported to be associated with the disease, but only one (APOE) has been independently replicated. I performed large scale (60 SNPs) association analysis to test for association with early onset form of AD. Despite observing 12 positive association signals in a set of 121 patients and matched controls, the signals were not robust enough to survive an independent confirmation study in a set of 117 patients and 176 controls.
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| 3. |
- Emahazion, Tesfai, et al.
(författare)
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Identification of 167 Polymorphisms in 88 Genes from Candidate Neurodegeneration Pathways
- 1999
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Ingår i: Gene. - 0378-1119 .- 1879-0038. ; 238:2, s. 315-324
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Tidskriftsartikel (refereegranskat)abstract
- Catalogs of intra-gene polymorphisms are needed to facilitate wide-ranging candidate gene-based association studies in common complex diseases. With this in mind, we have scanned multiple alignments of expressed sequence tags and of genomic DNA sequences (PCR products from four to eight unrelated individuals) to find polymorphisms in 195 genes putatively involved in neurodegenerative illness (including components of oxidative stress, excitotoxicity, inflammation, apoptosis and aging). This led to the discovery of 167 polymorphisms in 88 genes. These comprised 163 single nucleotide polymorphisms, one insertion/deletion, and three other variations involving more than one base pair. The polymorphisms were distributed in the exons (87), introns (70), and gene flanking regions (10). Of the exonic polymorphisms, 17 would give rise to non-synonymous amino acid substitutions. These findings now provide a valuable resource for association studies in neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease.
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| 6. |
- Yilmaz, Selma, et al.
(författare)
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Generation of a Ni(II) binding site by introduction of a histidine cluster in the structure of human glutathione transferase A1-1
- 1995
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Ingår i: Protein Engineering. - : Oxford University Press (OUP). - 0269-2139 .- 1460-213X. ; 8:11, s. 1163-1169
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Tidskriftsartikel (refereegranskat)abstract
- Two mutant forms of human glutathione transferase (GST) A1-1 with affinity for metal ions were constructed by introduction of His residues by site-directed mutagenesis. A mutant, 2-His, contained the mutations Lys84Gln, Asp85His and Glu88His, and another, 5-His, contained the mutations Tyr79His, Asn80His, Lys84His, Asp85His and Glu88His. The mutant proteins were obtained in good yields (40-150 mg per 3 l culture) by heterologous expression in Escherichia coli. The mutant enzymes possessed novel binding affinities for Ni(II) and Zn(II) ions, as demonstrated by immobilized metal ion affinity chromatography. The mutant with two novel His residues (2-His mutant) did not bind as tightly to immobilized Ni(II) as did the mutant with five novel His residues (5-His mutant). When tested for affinity to immobilized Zn(II), only the 5-His mutant remained bound to the column. The affinity of the 5-His mutant for Ni(II) ions in solution was determined by binding experiments in an aqueous polymeric two-phase system. Analysis of the binding curve showed two binding sites per enzyme subunit and a dissociation constant of 6.7 +/- 1.6 mu M. The kinetic constants kcat, Km and kcat/Km for the reaction with glutathione and 1-chloro-2,4-dinitrobenzene were determined by steady-state kinetic analysis and the parameter values for the mutant forms were found to be indistinguishable from those obtained for the wild-type GST A1-1. The differences in surface charge in the mutant proteins as compared with the wild-type enzyme did not alter the pH dependence of kcat. The results provide an alternative method for purification of fully active recombinant GST A1-1 by the introduction of novel metal binding sites. The data also showed that two His residues are sufficient for Ni(II) binding.
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