We cloned and sequenced the cDNAs for R-type pyruvate kinase (R-PK) from three homozygous PK patients. A point mutation (1151ACG to ATG) identified in the R-PK cDNA of PK Nagasaki was identical with that previously identified in an unrelated family, PK Tokyo. The mutation has also been identified in the PK L gene of a Lebanese family, PK Beirut, by Neubauer et al (Blood 77:1871, 1991). These re...

Biological phenotypes of tri-segmented arboviruses display characteristics that map to mutation/s in the S, M or L segments of the genome. Plaque variants have been characterized for other viruses displaying varied phenotypes including attenuation in growth and/or pathogenesis. In order to characterize variants of Bunyamwera and Ngari viruses, we isolated individual plaque size variants; small ...

Codon-tRNA coevolution to maximize protein production has been, until recently, the dominant hypothesis to explain codon-usage bias in highly expressed bacterial genes. Two predictions of this hypothesis are 1) selection is weak; and 2) similar silent replacements at different codons should have similar fitness consequence. We used an allele-replacement strategy to change five specific 3rd-codo...

Background: Beta thalassemia is a common health problem in Iran especially in Northern provinces. Premarital screening for thalassemia is compulsory in Iran and identification of the carriers is based on primary CBC (Cell Blood Count) and hemoglobin electrophoresis. Silent mutations on β-globin gene have borderline or normal hematological indices that cannot be detected in premarital scree...

Selection and mutation rates are estimated from aligned DNA sequences by using a Poisson random field model for base frequencies at polymorphic sites. This approach is applied at amino acid polymorphic codon positions to estimate selection rates against observed amino acid polymorphisms and also the proportion of codon positions that admit a weakly selected replacement. The technique can also b...

Background: Phenylketonuria as the most common genetic metabolic disorder is the result of disruption of the phenylalanine hydroxylase gene. This study was carried out to explore the phenylalanine hydroxylase gene mutation status of Iranian phenylketonuria patients.    Methods: Blood samples were collected from 30 patients, and hot spot areas of the phenylalanine hydroxylase gene, in...

Tay-Sachs disease (TSD) is a recessively inherited neurodegenerative disorder caused by mutations in the HEXA gene resulting in β-hexosaminidase A (HEX A) deficiency and neuronal accumulation of GM2 ganglioside. We describe the first patient with Tay-Sachs disease in the Cypriot population, a juvenile case which presented with developmental regression at the age of five. The diagnosis was confi...

Synonymous mutations do not alter amino acids and are generally considered nonfunctional in cancer. Supek et al. now present a compelling analysis suggesting that such silent mutations can be oncogenic by altering transcript splicing and thereby affecting protein function.

R-lineage mitochondrial DNA represents over 90% of the European population and is significantly present all around the planet (North Africa, Asia, Oceania, and America). This lineage played a major role in migration "out of Africa" and colonization in Europe. In order to determine an accurate dating of the R lineage and its sublineages, we analyzed 1173 individuals and complete mtDNA sequences ...

• Recessive mutations are due to loss-of-function by the protein product. • Dominant mutations result from a gain-of-function. • Testing whether a gene is essential requires a null mutation (one that completely eliminates its function). • Silent mutations have no effect, either because the base change does not change the sequence or amount of protein, or because the change in protein sequence h...