Search results for "MISSENSE MUTATION"
showing 10 items of 223 documents
Actin-related myopathy without any missense mutation in the ACTA1 gene.
2004
Actinopathies are defined by missense mutations in the ACTA1 gene coding for sarcomeric actin, of which some 70 families have, so far, been identified. Often, but not always, muscle fibers carry large patches of actin filaments. Many such patients also have nemaline myopathy, qualifying actinopathies as a subgroup of nemaline myopathies. This article concerns a then newborn, now 21/2-year-old boy, the first and single child of nonconsanguineous parents, who was born floppy, requiring immediate postnatal assisted ventilation. A quadriceps muscle biopsy revealed large patches of thin myofilaments reacting at light and electron microscopic levels with antibodies against actin but only a few s…
A multi-centre clinico-genetic analysis of the VPS35 gene in Parkinson disease indicates reduced penetrance for disease-associated variants
2012
Abstract: Background Two recent studies identified a mutation (p.Asp620Asn) in the vacuolar protein sorting 35 gene as a cause for an autosomal dominant form of Parkinson disease. Although additional missense variants were described, their pathogenic role yet remains inconclusive. Methods and results We performed the largest multi-center study to ascertain the frequency and pathogenicity of the reported vacuolar protein sorting 35 gene variants in more than 15,000 individuals worldwide. p.Asp620Asn was detected in 5 familial and 2 sporadic PD cases and not in healthy controls, p.Leu774Met in 6 cases and 1 control, p.Gly51Ser in 3 cases and 2 controls. Overall analyses did not reveal any sig…
A c.1244G>A (p.Arg415Gln) mutation in SH3BP2 gene causes cherubism in a Turkish family: report of a family with review of the literature
2014
Objectives: The present study was aimed at advancing the understanding of the pathogenesis of cherubism by presenting a case study based on history, physical examination, typical radiological features, molecular and histo - pathological laboratory tests and a review of the literature. Study Design: This study began with a 7-year-old boy who was referred due to mandibular overgrowth. A pan - oramic radiograph revealed multilocular radiolucent lesions of the upper/lower jaws suggestive of cherubism. Overall, a total of four family members were tested for SH3BP2 mutations, namely two siblings and their parents. Both siblings had been clinically diagnosed with cherubism; however, the parents we…
Two distinct phenotypes, hemiplegic migraine and episodic Ataxia type 2, caused by a novel common CACNA1A variant
2020
Abstract Background To investigate the genetic and environmental factors responsible for phenotype variability in a family carrying a novel CACNA1A missense mutation. Mutations in the CACNA1A gene were identified as responsible for at least three autosomal dominant disorders: FHM1 (Familial Hemiplegic Migraine), EA2 (Episodic Ataxia type 2), and SCA6 (Spinocerebellar Ataxia type 6). Overlapping clinical features within individuals of some families sharing the same CACNA1A mutation are not infrequent. Conversely, reports with distinct phenotypes within the same family associated with a common CACNA1A mutation are very rare. Case presentation A clinical, molecular, neuroradiological, neuropsy…
Natural and engineered carboxy-terminal variants: decreased secretion and gain-of-function result in asymptomatic coagulation factor VII deficiency.
2012
We report 2 asymptomatic homozygotes for the nonsense p.R462X mutation affecting the carboxy-terminus of coagulation factor VII (FVII, 466 aminoacids). FVII levels of 3-5% and 2.7 ± 0.4% were found in prothrombin time-based and activated factor X (FXa) generation assays with human thromboplastins. Noticeably, FVII antigen levels were barely detectable (0.7 ± 0.2%) which suggested a gain-of-function effect. This effect was more pronounced with bovine thromboplastin (4.8 ± 0.9%) and disappeared with rabbit thromboplastin (0.7 ± 0.2%). This suggests that the mutation influences tissue factor/FVII interactions. Whereas the recombinant rFVII-462X variant confirmed an increase in specific activit…
Prevalence of ANGPTL3 and APOB gene mutations in subjects with combined hypolipidemia.
2012
Objective— Mutations of the ANGPTL3 gene have been associated with a novel form of primary hypobetalipoproteinemia, the combined hypolipidemia (cHLP), characterized by low total cholesterol and low HDL-cholesterol levels. The aim of this work is to define the role of ANGPTL3 gene as determinant of the combined hypolipidemia phenotype in 2 large cohorts of 913 among American and Italian subjects with primary hypobetalipoproteinemia (total cholesterol <5th percentile). Methods and Results— The combined hypolipidemia cut-offs were chosen according to total cholesterol and HDL-cholesterol levels reported in the ANGPTL3 kindred described to date: total cholesterol levels, <2nd percentile …
Mutations in the PDS Gene in German Families with Pendred’s Syndrome: V138F Is a Founder Mutation
2003
Pendred's syndrome, an autosomal-recessive condition characterized by congenital sensorineural hearing loss and goiter, is caused by mutations in the PDS gene. Located on chromosome 7q22-q31, it encodes a chloride-iodide transporter expressed in the thyroid, inner ear, and kidney. We investigated the PDS gene of six affected individuals from four unrelated families with Pendred's syndrome by direct sequencing. PDS mutations were identified in homozygous or compound heterozygous state in all six cases. A homozygous missense mutation leading to the amino acid substitution S133T was detected in a family of Turkish origin. The mutations found in the other affected individuals, who originate fro…
Increased Activity of Coagulation Factor XII (Hageman Factor) Causes Hereditary Angioedema Type III
2006
International audience; Hereditary angioedema (HAE) is characterized clinically by recurrent acute skin swelling, abdominal pain, and potentially life-threatening laryngeal edema. Three forms of HAE have been described. The classic forms, HAE types I and II, occur as a consequence of mutations in the C1-inhibitor gene. In contrast to HAE types I and II, HAE type III has been observed exclusively in women, where it appears to be correlated with conditions of high estrogen levels--for example, pregnancy or the use of oral contraceptives. A recent report proposed two missense mutations (c.1032C-->A and c.1032C-->G) in F12, the gene encoding human coagulation factor XII (FXII, or Hageman factor…
Mandibular-pelvic-patellar syndrome (mpp) is a novel pitx1-related disorder due to alteration of pitx1 transactivation ability
2020
International audience; PITX1 is a homeobox transcription factor essential for hindlimb morphogenesis. Two PITX1-related human disorders have been reported to date: PITX1 ectopic expression causes Liebenberg syndrome, characterized by malformation of upper limbs showing a "lower limb" appearance; PITX1 deletions or missense variation cause a syndromic picture including clubfoot, tibial hemimelia, and preaxial polydactyly. We report two novel PITX1 missense variants, altering PITX1 transactivation ability, in three individuals from two unrelated families showing a distinct recognizable autosomal dominant syndrome, including first branchial arch, pelvic, patellar, and male genital abnormaliti…
Novel missense mutation in the ATP1A2 gene associated with atypical sporapedic hemiplegic migraine
2019
Hemiplegic migraine (HM) is a rare subtype of migraine with aura in which attacks include transient motor weakness or hemiparesis that can last several days. HM is linked to mutations in three different genes, CACNA1A, ATP1A2 and SCN1A, which encode for ion transporters. The clinical spectrum includes atypical symptoms such as impaired consciousness, epileptic seizures, permanent cerebellar ataxia or mental retardation. We describe a novel mutation found in the ATP1A2 gene in a patient with late-onset HM. His attacks were characterised by motor weakness associated with altered mental status, diplopia and ataxia. He also showed up MRI abnormalities and incomplete response to prophylactic the…