Search results for "Missense"

Congenital secondary hypothyroidism caused by exon skipping due to a homozygous donor splice site mutation in the TSHbeta-subunit gene.

2002

Isolated TSH deficiency as a cause for congenital hypothyroidism is relatively uncommon. Even more rare is the identification of mutations in the TSHβ gene, only four of which have been identified. We here report a 4-month-old girl with isolated TSH deficiency born to consanguineous parents. Sequencing of the TSHβ-subunit gene revealed a homozygous G to A transition at position +5 of the donor splice site of intron 2. TSHβ gene transcript could not be obtained from fibroblasts or white blood cells by illegitimate amplification. Thus, to investigate further the mechanism leading to TSH deficiency in this patient, we used an in vitro exon-trapping system. The mutation at position +5 of the do…

Missense Mutations in the Proline-Rich Region of Coagulation Factor XII in Hereditary and Idiopathic Angioedema.

2006

Abstract Hereditary angioedema (HAE) is characterized by recurrent skin swelling, abdominal pain attacks, and potentially life-threatening upper airway obstruction. The two classic HAE types (I and II) are caused by mutations in the complement C1 inhibitor gene, resulting in a functional deficiency of C1 inhibitor. Recently, a novel type of hereditary angioedema has been described, these patients showing normal C1 inhibitor concentration and activity in plasma (HAE with normal C1 inhibitor, HAE type III). With few exceptions, all reported patients have been women, and exposition to estrogens appears to be an important precipitating factor. Screening of twenty unrelated female patients with …

Factor V Leiden Is Associated with Repeated and Recurrent Unexplained Fetal Losses

1997

SummaryActivated protein C resistance (APCR) is responsible for most cases of familial thrombosis. The factor V missense mutation Arg506>Gln (FV Leiden) has been recognized as the commonest cause of this condition. Recently, it has been suggested that APCR is associated with second trimester fetal loss. We investigated the distribution of FV Leiden in a sample (n = 43) of Caucasian women with a history of two or more unexplained fetal losses. A group (n = 118) of parous women with uneventful pregnancies from the same ethnical background served as control. We found the mutation in 7 cases (16.28%) and 5 controls (4.24%; p = 0.011). A statistically significant difference between women with…

Genetic variants in the MTHFR are not associated with fatty liver disease.

2020

The common missense sequence variants of methylenetetrahydrofolate reductase (MTHFR), rs1801131 (c.A1298C) and rs1801133 (c.C677T), favour the development of hyperhomocysteinemia and diminished DNA methylation. Previous studies, carried out in small series and with suboptimal characterization of the hepatic phenotype, tested the association of these genetic variants with fatty liver disease (FLD), with conflicting results. Here, we assessed the association of rs1801131 and rs1801133 with hepatic phenotype in the Liver Biopsy Cross-Sectional Cohort, a large cohort (n=1375 from Italy and 411 from Finland) of European individuals with suspect FLD associated with dysmetabolism. A total of 1786 …

A leptin missense mutation associated with hypogonadism and morbid obesity

1998

2015

Ocular signs in Fabry disease have generally been regarded to be primarily of diagnostic value. We explored whether ocular findings, alone or in particular in combination with the α-galactosidase A gene mutation, have predictive value for disease severity. Data from the Fabry Outcome Survey (FOS), a large, global database sponsored by Shire, were selected for adult patients who had undergone ophthalmological examination. Three ocular signs were assessed: cornea verticillata, tortuous conjunctival and/or retinal vessels, and cataract. Fabry disease severity was measured using FOS Mainz Severity Score Index and modifications thereof. Ophthalmological data were available for 1203 (699 female, …

F9 missense mutations impairing factor IX activation are associated with pleiotropic plasma phenotypes.

2022

Background Circulating dysfunctional factor IX (FIX) might modulate distribution of infused FIX in hemophilia B (HB) patients. Recurrent substitutions at FIX activation sites (R191-R226, >300 patients) are associated with variable FIX activity and antigen (FIXag) levels. Objectives To investigate the (1) expression of a complete panel of missense mutations at FIX activation sites and (2) contribution of F9 genotypes on the FIX pharmacokinetics (PK). Methods We checked FIX activity and antigen and activity assays in plasma and after recombinant expression of FIX variants and performed an analysis of infused FIX PK parameters in patients (n = 30), mostly enrolled in the F9 Genotype and PK HB …

FUNCTIONAL EFFECT OF NOVEL AMINO ACID VARIANTS OF APOLIPOPROTEIN B IN FAMILIAL HYPOBETALIPOPROTEINEMIA

2011

Introduction. Familial Hypobetalipoproteinemia (FHBL) is a codominant disorder characterized by reduced plasma levels of LDL-C and apolipoprotein (apo) B. In 50% of cases FHBL is due to mutations in APOB gene resulting in truncated apoBs of various size. Some mutations in APOB gene resulting in non-conservative amino acid substitutions were reported to cause FHBL. In vitro, these mutations induce the retention of the mutant apoB in the endoplasmic reticulum (ER) and impair the secretion of apoB-containing lipoproteins. In two FHBL subjects we identified two novel amino acid variants (Thr26_27delinsAsn and Tyr102Cys) located in the N-terminal 1000 amino acids of mature apoB. Methods. To inve…

Does δ-sarcoglycan-associated autosomal-dominant cardiomyopathy exist?

2009

In this study we clinically and genetically characterize a consanguineous family with a homozygous novel missense mutation in the delta-sarcoglycan gene and a second delta-sarcoglycan mutation that has previously been reported to cause severe autosomal-dominant dilated cardiomyopathy. We identified a novel missense mutation in exon 6 (p.A131P) of the delta-sarcoglycan gene, which in a homozygous state leads to the clinical picture of a limb girdle muscular dystrophy. In four heterozygous carriers for the mutation, aged 3-64 years, a second sequence variant in exon 6 (p.S151A) of the delta-sarcoglycan gene was detected on the other allele. This second missense change had previously been repo…

Abnormalities in alpha-dystroglycan expression in MDC1C and LGMD2I muscular dystrophies

2004

We recently identified mutations in the fukutin related protein (FKRP) gene in patients with congenital muscular dystrophy type 1C (MDC1C) and limb girdle muscular dystrophy type 2I (LGMD2I). The sarcolemma of these patients typically displays an immunocytochemical reduction of alpha-dystroglycan. In this report we extend these observations and report a clear correlation between the residual expression of alpha-dystroglycan and the phenotype. Three broad categories were identified. Patients at the severe end of the clinical spectrum (MDC1C) were compound heterozygote between a null allele and a missense mutation or carried two missense mutations and displayed a profound depletion of alpha-d…