Search results for "MUTATION"
showing 10 items of 2830 documents
Mutagenesis scanning uncovers evolutionary constraints on tobacco etch Potyvirus membrane-associated 6K2 protein
2019
RNA virus high mutation rate is a double-edged sword. At the one side, most mutations jeopardize proteins functions; at the other side, mutations are needed to fuel adaptation. The relevant question then is the ratio between beneficial and deleterious mutations. To evaluate this ratio, we created a mutant library of the 6K2 gene of tobacco etch potyvirus that contains every possible single-nucleotide substitution. 6K2 protein anchors the virus replication complex to the network of endoplasmic reticulum membranes. The library was inoculated into the natural host Nicotiana tabacum, allowing competition among all these mutants and selection of those that are potentially viable. We identified 1…
Recent results on syntactic groups of prefix codes
2012
International audience; We give a simplified presentation of groups in transformation monoids. We use this presentation to describe two recent results on syntactic groups of prefix codes. The first one uses Sturmian words to build finite bifix codes with a given permutation group as syntactic group. The second one describes a class of prefix codes such that all their syntactic groups are cyclic.
Commensurability in Artin groups of spherical type
2019
Let $A$ and $A'$ be two Artin groups of spherical type, and let $A_1,\dots,A_p$ (resp. $A'_1,\dots,A'_q$) be the irreducible components of $A$ (resp. $A'$). We show that $A$ and $A'$ are commensurable if and only if $p=q$ and, up to permutation of the indices, $A_i$ and $A'_i$ are commensurable for every $i$. We prove that, if two Artin groups of spherical type are commensurable, then they have the same rank. For a fixed $n$, we give a complete classification of the irreducible Artin groups of rank $n$ that are commensurable with the group of type $A_n$. Note that it will remain 6 pairs of groups to compare to get the complete classification of Artin groups of spherical type up to commensur…
Homozygous familial hypobetalipoproteinemia: two novel mutations in the splicing sites of apolipoprotein B gene and review of the literature.
2015
Objective: Familial hypobetalipoproteinemia (FHBL) is autosomal codominant disorder of lipoprotein metabolism characterized by low plasma levels of total cholesterol (TC), low-density lipoproteincholesterol (LDL-C) and apolipoprotein B (apoB) below the 5 th percentile of the distribution in the population. Patients with the clinical diagnosis of homozygous FHBL (Ho-FHBL) are extremely rare and few patients have been characterized at the molecular level. Here we report the medical history and the molecular characterization of one paediatric patient with clinical features of Ho-FHBL. Methods: A one month old infant with failure to thrive, severe hypocholesterolemia and acanthocytosis was clin…
Novel CREB3L3 Nonsense Mutation in a Family With Dominant Hypertriglyceridemia.
2015
Objective— Cyclic AMP responsive element–binding protein 3–like 3 ( CREB3L3 ) is a novel candidate gene for dominant hypertriglyceridemia. To date, only 4 kindred with dominant hypertriglyceridemia have been found to be carriers of 2 nonsense mutations in CREB3L3 gene (245fs and W46X). We investigated a family in which hypertriglyceridemia displayed an autosomal dominant pattern of inheritance. Approach and Results— The proband was a 49-year-old woman with high plasma triglycerides (≤1300 mg/dL; 14.68 mmol/L). Her father had a history of moderate hypertriglyceridemia, and her 51-year-old brother had triglycerides levels as high as 1600 mg/dL (18.06 mmol/L). To identify the causal mutation …
Germline correction of an epimutation related to Silver-Russell syndrome.
2015
Like genetic mutations, DNA methylation anomalies or epimutations can disrupt gene expression and lead to human diseases. However, unlike genetic mutations, epimutations can in theory be reverted through developmental epigenetic reprograming, which should limit their transmission across generations. Following the request for a parental project of a patient diagnosed with Silver-Russell syndrome (SRS), and the availability of both somatic and spermatozoa DNA from the proband and his father, we had the exceptional opportunity to evaluate the question of inheritance of an epimutation. We provide here for the first time evidence for efficient reversion of a constitutive epimutation in the sperm…
Genetic diagnosis of familial hypercholesterolemia in a South European outbreed population: influence of low-density lipoprotein (LDL) receptor gene …
2001
The aims of this study were to examine the presence of mutations in the low-density lipoprotein receptor gene among subjects clinically diagnosed with familial hypercholesterolemia and to analyze whether the molecular diagnosis helps to predict the response to simvastatin treatment in our familial hypercholesterolemia population. Fifty-five probands and 128 related subjects with familial hypercholesterolemia were studied. Genetic diagnosis was carried out following a three-step protocol based on Southern blot and PCR-single strand conformational polymorphism analysis. A randomized clinical trial with simvastatin was conducted in 42 genetically diagnosed subjects with familial hypercholester…
Y179C, F486L and N550H are BRCA1 variants that may be associated with breast cancer in a Sicilian family: results of a 5-year GOIM (Gruppo Oncologico…
2006
Background Over 600 different pathogenic mutations have been identified in the BRCA1 gene. Nevertheless, numerous missense mutations of unknown biological function still exist. Understanding of biological significance of these mutations should help in genetic counselling to carriers and their families. Patients and methods A total of 104 patients with breast and/or ovarian cancer whose genetic counselling answered the criteria of the American Society of Clinical Oncology (ASCO 2003), were prospectively screened for mutations in all coding exons of the BRCA1 gene by automatic direct sequencing. Results During these mutational screening procedures one case presented three mutations classified…
Mutations in MTP gene in abeta- and hypobeta-lipoproteinemia.
2005
Abstract Familial hypobetalipoproteinemia (FHBL) and abetalipoproteinemia (ABL) are inherited disorders of apolipoprotein B (apo B)-containing lipoproteins that result from mutations in apo B and microsomal triglyceride transfer protein (MTP) genes, respectively. Here we report three patients with severe deficiency of plasma low-density lipoprotein (LDL) and apo B. Two of them (probands F.A. and P.E.) had clinical and biochemical phenotype consistent with ABL. Proband F.A. was homozygous for a minute deletion/insertion (c.1228delCCCinsT) in exon 9 of MTP gene predicted to cause a truncated MTP protein of 412 amino acids. Proband P. E. was heterozygous for a mutation in intron 9 (IVS9-1G>A),…
No evidence of ATP1A2 involvement in 12 multiplex Italian families with benign familial infantile seizures
2005
A missense mutation in the gene encoding the alpha(2) Subunit of the Na+,K+ ATPase pump (ATP1A2) was found in a family with both familial hemiplegic migraine (FHM) and Benign Familial Infantile Seizures (BFIC). As it is still unclear whether ATP1A2 is responsible for pure BFIC syndromes, we checked mutations of the ATP1A2 gene in probands of 12 Italian multiplex families with pure BFIC, who were negative for mutations in the SCN2A gene. We screened the ATP1A2 gene by denaturing high performance liquid chromatography (D-HPLC) and direct sequencing of DNA fragments showing an aberrant elution pattern. We found one exonic variant and five intronic variants, none leading to significant amino ac…