Search results for " Mutation"

Point mutations associated with Leber hereditary optic neuropathy in a Latvian population

2013

Purpose To study mutations associated with Leber hereditary optic neuropathy (LHON) in patients suspected of having this mitochondrial disorder in a Latvian population. Additional aims were to determine the heteroplasmy status of all non-synonymous polymorphisms identified in the current study and to identify the mitochondrial haplogroups of the studied participants because these factors may contribute to the manifestation of LHON. Methods Twelve patients, including patients in two families, were enrolled in the current study. LHON was suspected based on the findings of ophthalmologic examinations. In clinically affected individuals, the presence of all previously reported LHON-associated m…

Subclinical hyperthyroidism due to a thyrotropin receptor (TSHR) gene mutation (S505R).

2006

Aim: To identify the molecular defect by which non-autoimmune subclinical hyperthyroidism was caused in a 6-mo-old infant who presented with weight loss. Methods: Congenital non-autoimmune hyperthyroidism is caused by activating germline mutations in the thyrotropin receptor (TSHR) gene. Therefore, the TSHR gene was sequenced directly from the patient's genomic DNA. Results: Molecular analysis revealed a heterozygous point mutation (S505R) in the TSHR gene as the underlying defect. Conclusion: A constitutively activating mutation in the TSHR gene has to be considered not only in patients with severe congenital non-autoimmune hyperthyroidism, but also in children with subclinical non-autoimm…

Congenital goitrous primary hypothyroidism in two German families caused by novel thyroid peroxidase (TPO) gene mutations.

2013

Congenital hypothyroidism occurs with a prevalence of approximately 1:3 500. Defects in thyroid hormone synthesis which lead to goitrous hypothyroidism account for 10-15% of these cases. Several genetic defects have been characterized and mutations in the thyroid peroxidase (TPO) gene are the most common cause for dyshormonogenesis.So far, more than 80 mutations in the TPO gene have been described, resulting in a variable decrease in TPO bioactivity. Clinically TPO defects manifest with congenital primary goitrous hypothyroidism.We here present 2 children with congenital primary hypothyroidism, who were identified to have compound heterozygous TPO mutations. They both shared the same novel …

Ten novel mutations found in Aniridia.

1998

Aniridia (AN) is a sight-threatening congenital ocular disorder characterized by iris hypoplasia, corneal pannus, foveal and optic nerve hypoplasia, cataract formation, and glaucoma. In two-thirds of the patients, AN is inherited in an autosomal dominant fashion with almost complete penetrance but variable expression. The remaining cases are sporadic. Aniridia has been shown to be associated with mutations in the PAX6 gene, located on chromosome 11p13, telomeric to the Wilms' tumor predisposition gene (WT1). This paper describes 14 mutations in the PAX6 gene in patients with AN. Among these 14 mutations, 10 have been unpublished until now. They result most probably in haploinsufficiency and…

Influence of CYP3A5 and ABCB1 gene polymorphisms and other factors on tacrolimus dosing in Caucasian liver and kidney transplant patients

2011

Tacrolimus is a substrate of cytochrome P4503A (CYP3A) enzymes as well as of the drug transporter ABCB1. We have investigated the possible influence of CYP3A5 and ABCB1 single nucleotide polymorphisms (SNPs) and other factors (e.g. albumin, hematocrit and steroids) on tacrolimus blood levels achieved in a population of Caucasian liver (n=51) and kidney (n=50) transplant recipients. At 1, 3 and 6 months after transplantation, tacrolimus doses (mg/kg/day) and trough blood levels (C0) were recorded and the weight-adjusted tacrolimus dosage (mg/kg/day) was calculated. Polymerase chain reaction followed by restriction fragment length polymorphism analysis was used for genotyping CYP3A5*1 and *3 …

Gender specific associations of the Trp64Arg mutation in the beta3-adrenergic receptor gene with obesity-related phenotypes in a Mediterranean popula…

2001

Abstract. Corella D, Guillen M, Portoles O, Sorli JV, Alonso V, Folch J, Saiz C (School of Medicine, University of Valencia, Valencia, Spain). Gender specific associations of the Trp64Arg mutation in the β3-adrenergic receptor gene with obesity-related phenotypes in a Mediterranean population: interaction with a common lipoprotein lipase gene variation. J Intern Med 2001; 250: 348–360. Objective. To investigate the association between the Trp64Arg β3-adrenergic receptor (ADRB3) mutation and obesity-related phenotypes in a Mediterranean Spanish population considering the effect of other genetic and environmental factors. Design and subject. Cross-sectional study in 1063 (476 men and 587 wome…

Role of factor V Leiden or G20210A prothrombin mutation in patients with symptomatic pulmonary embolism and deep vein thrombosis: a meta-analysis of …

2012

Kallikrein–kinin system and fibrinolysis in hereditary angioedema due to factor XII gene mutation Thr309Lys

2009

In a subgroup of hereditary angioedema (HAE) patients with normal C1-esterase inhibitor levels, HAE is caused by a Thr309Lys mutation in the coagulation factor XII (F12) gene. The aim of this study was to examine elements of the kallikrein-kinin system ('contact system') and the downstream-linked coagulation, complement and fibrinolytic systems in the plasma of six patients with HAE caused by the Thr309Lys mutation and healthy probands. Blood samples were taken from participants during the symptom-free interval between attacks. Samples were analyzed for activity and concentrations of components of the kallikrein-kinin system and linked enzyme systems. The mean FXII clotting activity was 90%…

Increased sensitivity of the neuronal nicotinic receptor alpha-2 subunit causes familial epilepsy with nocturnal wandering and ictal fear

2006

Sleep has traditionally been recognized as a precipitating factor for some forms of epilepsy, although differential diagnosis between some seizure types and parasomnias may be difficult. Autosomal dominant frontal lobe epilepsy is characterized by nocturnal seizures with hyperkinetic automatisms and poorly organized stereotyped movements and has been associated with mutations of the α4 and β2 subunits of the neuronal nicotinic acetylcholine receptor. We performed a clinical and molecular genetic study of a large pedigree segregating sleep-related epilepsy in which seizures are associated with fear sensation, tongue movements, and nocturnal wandering, closely resembling nightmares and sleep …

Intragenic KANSL1 mutations and chromosome 17q21.31 deletions: broadening the clinical spectrum and genotype-phenotype correlations in a large cohort…

2015

Background The 17q21.31 deletion syndrome phenotype can be caused by either chromosome deletions or point mutations in the KANSL1 gene. To date, about 60 subjects with chromosome deletion and 4 subjects with point mutation in KANSL1 have been reported. Prevalence of chromosome deletions compared with point mutations, genotype–phenotype correlations and phenotypic variability have yet to be fully clarified. Methods We report genotype–phenotype correlations in 27 novel subjects with 17q21.31 deletion and in 5 subjects with KANSL1 point mutation , 3 of whom were not previously reported. Results The prevalence of chromosome deletion and KANSL1 mutation was 83% and 17%, respectively. All patient…