Search results for "Heterozygote advantage"
showing 10 items of 56 documents
A Single Copy of the Recently Identified Dual Oxidase Maturation Factor (DUOXA) 1 Gene Produces Only Mild Transient Hypothyroidism in a Patient with …
2011
Dual oxidases (DUOX1 and DUOX2) play a crucial role in the generation of hydrogen peroxide required in the oxidation of iodide and the synthesis of thyroid hormone. Heterodimerization with specific maturation factors (DUOXA1 and DUOXA2) is essential for the maturation and function of the DUOX enzyme complexes. Biallelic loss-of-function mutations of DUOX2 result in congenital hypothyroidism (CH), whereas a single reported case of homozygous DUOXA2 mutation (Y246X) has been associated with mild CH.We now report an infant with transient CH due to a complex genetic alteration of the DUOX/DUOXA system.Our patient was born to euthyroid nonconsanguineous parents and presented with an elevated TSH…
Delineation of a new chromosome 20q11.2 duplication syndrome including the ASXL1 gene.
2013
We report on three males with de novo overlapping 7.5, 9.8, and 10 Mb duplication of chromosome 20q11.2. Together with another patient previously published in the literature with overlapping 20q11 microduplication, we show that such patients display common clinical features including metopic ridging/trigonocephaly, developmental delay, epicanthal folds, and short hands. The duplication comprised the ASXL1 gene, in which de novo heterozygous nonsense or truncating mutations have recently been reported in patients with Borhing-Opitz syndrome. Because of craniofacial features in common with Borhing-Opitz syndrome, in particular metopic ridging/trigonocephaly, we suggest that duplication of ASX…
Mild mutations in the pan neural gene prospero affect male-specific behaviour in Drosophila melanogaster
2004
0376-6357 (Print) Journal Article Research Support, Non-U.S. Gov't; The fruitfly Drosophila melanogaster is one of the most appropriate model organisms to study the genetics of behaviour. Here, we focus on prospero (pros), a key gene for the development of the nervous system which specifies multiple aspects from the early formation of the embryonic central nervous system to the formation of larval and adult sensory organs. We studied the effects on locomotion, courtship and mating behaviour of three mild pros mutations. These newly isolated pros mutations were induced after the incomplete excision of a transposable genomic element that, before excision, caused a lethal phenotype during larv…
Head and neck paragangliomas: Report of 175 patients (1989-2010)
2011
Attention of the otorhinolaryngologist needs to be drawn to the versatile aspects of head and neck paragangliomas (PGLs).This study is a retrospective, nonrandomized clinical study of all 175 individuals with PGLs treated in our department between 1989 and 2010. A genetic analysis was performed on 86 patients.The 175 patients presented 224 head and neck PGLs as well as 2 thyroid papillary carcinomas. Genetic analysis resulted in 1 patient positive for a von Hippel-Lindau (VHL) gene mutation and 34 for succinate dehydrogenase (SDH) gene mutations (22 SDHD, 7 SDHC, and 5 SDHB), 12 of the latter carrying a novel mutation. Thirty-three patients (18.9%) had multiple PGLs and 11 patients (6.3%) h…
Spectrum of mutations of the LPL gene identified in Italy in patients with severe hypertriglyceridemia.
2015
Background: Monogenic hypertriglyceridemia (HTG) may result from mutations in some genes which impair the intravascular lipolysis of triglyceride (TG)-rich lipoproteins mediated by the enzyme Lipoprotein lipase (LPL). Mutations in the LPL gene are the most frequent cause of monogenic HTG (familial chylomicronemia) with recessive transmission. Methods: The LPL gene was resequenced in 149 patients with severe HTG (TG>10mmol/L) and 106 patients with moderate HTG (TG>4.5 and <10mmol/L) referred to tertiary Lipid Clinics in Italy. Results: In the group of severe HTG, 26 patients (17.4%) were homozygotes, 9 patients (6%) were compound heterozygotes and 15 patients (10%) were simple heter…
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…
Association Between Single Nucleotide Polymorphisms in the Cyclooxygenase-2, Tumor Necrosis Factor-α, and Vascular Endothelial Growth Factor-A Genes,…
2011
Cyclooxygenase-2 (COX-2), vascular endothelial growth factor-A (VEGF-A), and tumor necrosis factor-α (TNF-α) are mediators of inflammation and angiogenesis; all of them are produced in liver cirrhosis (LC) and in hepatocellular carcinoma (HCC). It was proposed that there is an association between single nucleotide polymorphisms (SNPs) and HCC. These allelic variants influence the transcriptional activity of these genes, and therefore the proteins levels. The VEGF-A pathway is a potential therapeutic target in HCC, and several antiangiogenic agents have entered clinical trials in HCC. We evaluated the frequency of SNPs of COX-2, TNF-α, and VEGF-A genes in patients with HCC versus LC patients…
Gene diagnosis and carrier detection in Hunter syndrome by the iduronate-2-sulphatase cDNA probe.
1992
Hunter disease (McKusick 309900) is an X-chromosomal mucopolysaccharidosis due to deficiency of the lysosomal enzyme iduronate-2-sulphatase (IDS; EC 3.1.6.13). Diagnosis is based on both the typical clinical features of patients and the lack/reduction of IDS activity. Female carriers show no symptoms of the disease. In the past, several different assays were elaborated for measuring enzyme activity in carriers but none of them proved to be suitable for detecting heterozygotes reliably (Zlotogora and Bach 1984)
Oligosaccharide and Ganglioside Neuraminidase Activities of Mucolipidosis I (Sialidosis) and Mucolipidosis II (I-Cell Disease) Fibroblasts
1979
Fibroblasts cultured from the skin of patients with the genetic diseases mucolipidosis I and mucolipidosis II were found deficient in a neuraminidase specific for both an α23 and and α2 6 type of neuraminosyl linkage of sialyl oligosaccharides. Obligate heterozygotes (parents) showed an intermediate activity in mucolipidosis I, but a normal one in mucolipidosis II. The neuraminidase activity of mucolipidosis I fibroblasts towards gangliosides, measured at pH 4.5 in the presence of Triton X-100, was within the range of normal controls with gangliosides Gm3 and GD3, but somewhat diminished with a bovine brain ganglioside preparation. In mucolipidosis II, neuraminidase activity was markedly de…
Clinical, pathologic, and genetic features of massive soft tissue neurofibromas in a Sicilian patient
2008
Abstract CONTEXT: Lipase maturation factor 1 (LMF1) gene is a novel candidate gene in severe hypertriglyceridemia. Lmf1 is involved in the maturation of lipoprotein lipase (LPL) and hepatic lipase in endoplasmic reticulum. To date only one patient with severe hypertriglyceridemia and related disorders was found to be homozygous for a nonsense mutation in LMF1 gene (Y439X). OBJECTIVE: The objective of the study was to investigate LMF1 gene in hypertriglyceridemic patients in whom mutations in LPL, APOC2, and APOA5 genes had been excluded. RESULTS: The resequencing of LMF1 gene led to the discovery of a novel homozygous nonsense mutation in one patient with severe hypertriglyceridemia and rec…