Search results for "Point mutation"

Dejerine-Sottas neuropathy associated with De Novo S79P mutation of the peripheral myelin protein 22 (PMP22) gene

1998

A genome-wide view of Caenorhabditis elegans base-substitution mutation processes

2009

Knowledge of mutation processes is central to understanding virtually all evolutionary phenomena and the underlying nature of genetic disorders and cancers. However, the limitations of standard molecular mutation detection methods have historically precluded a genome-wide understanding of mutation rates and spectra in the nuclear genomes of multicellular organisms. We applied two high-throughput DNA sequencing technologies to identify and characterize hundreds of spontaneously arising base-substitution mutations in 10 Caenorhabditis elegans mutation-accumulation (MA)-line nuclear genomes. C. elegans mutation rate estimates were similar to previous calculations based on smaller numbers of m…

The STR252-IVS10nt546-VNTR7 phenylalanine hydroxylase minihaplotype in five Mediterranean samples.

1997

IVS10nt546 (IVS10nt-11g→a) is the most common molecular defect of the phenylalanine hydroxylase gene causing phenylketonuria in Mediterranean populations. Previous studies have proposed various and alternative hypotheses concerning the geographical origin and pattern of diffusion of this mutation in this area. In this study, this issue was re-examined on a large sample (149) of “Mediterranean” IVS10nt546 mutant alleles analysed with multiallelic intragenic polymorphisms. The analysis of intragenic microsatellite (STR) and minisatellite (VNTR) polymorphisms shows allelic heterogeneity of the IVS10nt546 mutation. Eight STR and three VNTR alleles were found in association with the splicing def…

Mutated tumor alleles are expressed according to their DNA frequency

2014

AbstractThe transcription of tumor mutations from DNA into RNA has implications for biology, epigenetics and clinical practice. It is not clear if mutations are in general transcribed and, if so, at what proportion to the wild-type allele. Here, we examined the correlation between DNA mutation allele frequency and RNA mutation allele frequency. We sequenced the exome and transcriptome of tumor cell lines with large copy number variations, identified heterozygous single nucleotide mutations and absolute DNA copy number and determined the corresponding DNA and RNA mutation allele fraction. We found that 99% of the DNA mutations in expressed genes are expressed as RNA. Moreover, we found a hig…

Chronic progressive external ophthalmoplegia with a novel mitochondrial DNA deletion and a mutation in the tRNALEU(UUR) gene

1999

Large-scale deletions and point mutations of the mitochondrial DNA are generally accepted as being involved in the pathogenesis of diseases associated with mitochondrial encephalomyopathies such as Kearns-Sayre syndrome and chronic progressive external ophthalmoplegia (CPEO). We screened suspected patients using polymerase chain reaction techniques, Southern blot analyses, and muscle biopsy specimens. We report on a novel 4,953-base pair deletion associated with a familial occurrence of a tRNA Leu(UUR) T3250C point mutation in a young female patient clinically diagnosed with CPEO. This deletion is not flanked by direct repeats, so slip replication and homologous recombination do not seem li…

Molecular basis of mucopolysaccharidosis type II: Mutations in the iduronate-2-sulphatase gene

1993

A number of mutations in the X-chromosomal human iduronate-2-sulphatase gene have now been identified as the primary genetic defect leading to the clinical condition known as Hunter syndrome or mucopolysaccharidosis type II. The mutations that are tabulated include different deletions, splice-site and point mutations. From the group of 319 patients thus far studied by Southern analysis, 14 have a full deletion of the gene and 48 have a partial deletion or other gross rearrangements. All patients with full deletions or gross rearrangements have severe clinical presentations. Twenty-nine different "small" mutations have so far been characterised in a total of 32 patients. These include 4 nons…

Identification of novel SLC3A1 gene mutations in Spanish cystinuria families and association with clinical phenotypes

2004

Cystinuria is an inherited metabolic disease characterized by an abnormal urinary excretion of cystine and dibasic amino acids, leading to kidney stone formation. Incidence of cystinuria in the Mediterranean Spanish population is one of the highest in the world. In view of the low prevalence of previously reported mutations in the SLC3A1 gene, analyses to identify novel variants were carried out on 20 cystinuria families. Additionally, we investigated the possible association between these molecular variants and clinical phenotypes. Genomic DNA from 48 cystinuria patients, 44 healthy relatives and 81 unrelated controls from the East Mediterranean coast of Spain was screened by conformation …

Molecular basis of adaptive convergence in experimental populations of RNA viruses

2002

Abstract Characterizing the molecular basis of adaptation is one of the most important goals in modern evolutionary genetics. Here, we report a full-genome sequence analysis of 21 independent populations of vesicular stomatitis ribovirus evolved on the same cell type but under different demographic regimes. Each demographic regime differed in the effective viral population size. Evolutionary convergences are widespread both at synonymous and nonsynonymous replacements as well as in an intergenic region. We also found evidence for epistasis among sites of the same and different loci. We explain convergences as the consequence of four factors: (1) environmental homogeneity that supposes an id…

Intermediate Filament Diseases: Desminopathy

2008

Desminopathy is one of the most common intermediate filament human disorders associated with mutations in closely interacting proteins, desmin and alphaB-crystallin. The inheritance pattern in familial desminopathy is characterized as autosomal dominant or autosomal recessive, but many cases have no family history. At least some and likely most sporadic desminopathy cases are associated with de novo DES mutations. The age of disease onset and rate of progression may vary depending on the type of inheritance and location of the causative mutation. Typically, the illness presents with lower and later upper limb muscle weakness slowly spreading to involve truncal, neck-flexor, facial and bulba…

Frequency of the HFE Gene Mutations in Five Italian Populations

2002

Abstract ABSTRACT Genetic hemochromatosis is an autosomal recessive disorder characterized by iron overload and a variety of clinical manifestations such as liver cirrhosis and arthropathy. It is the most common genetic disease of northern European populations. The principal gene responsible for hereditary hemochromatosis, designated HFE, is located on chromosome 6 in the HLA region. The single point mutation 845A, changing cysteine at position 282 to tyrosine (C282Y), in this gene has been identified as the main genetic basis of hereditary hemochromatosis. Two other mutations, 187G, a histidine to aspartate at amino acid 63 (H63D), and 193T, a serine to cysteine at amino acid 65 (S65C), ap…