Pavlíková M

Relationship between X-inactivation and clinical involvement in Fabry heterozygotes. Eleven novel mutations in the α-galactosidase A gene in the Czech and Slovak population

We have identified 21 different α-galactosidase A gene (GLA) mutations in 22 unrelated Czech and Slovak families with Fabry disease. Eleven of these mutations were novel (point mutations D93N, A135V, D155H, G171R, Q280K, G360S, Q330X, splicing errors c.194ins14, c.801ins36 and deletions c.674_732del59, g.3405_6021del2617). Genotyping of family members for family-specific mutations revealed 55 heterozygotes that manifested clinical symptoms of different severity. To examine the contribution of X-inactivation skewing to disease manifestation in Fabry heterozygotes, we have adopted the Mainz severity scoring scheme and compared the score values with the X-inactivation status in 39 carriers in an age-dependent manner. The age-score trendline of Fabry females who had a predominantly inactivated X-chromosome bearing a wild-type GLA allele (10 of 38 females) was markedly steeper than in the rest of the cohort. One female carrier with an inactivated mutated allele had a low score value when compared to the other heterozygotes of the same age. These data suggest that X-inactivation is indeed a major factor determining the severity of clinical involvement in Fabry heterozygotes. There was a statistically significant difference between the severity score values of heterozygotes with random and non-random X-chromosome inactivation at the 5% level of significance. Further studies will show if the degree of the wildtype allele inactivation will be useful as a predictive marker of severity of phenotype in Fabry heterozygotes. Although the correlation between X-inactivation skewing and presentation of the disease in Fabry heterozygotes has previously been suggested in the literature, this report is among the first attempts to examine this relationship systematically.

Genetic variants of homocysteine metabolizing enzymes and the risk of coronary artery disease.

It is unresolved whether elevated homocysteine in coronary artery disease (CAD) is the cause of arteriosclerosis or its consequence. In contrast, genetic variants of enzymes that metabolize homocysteine cannot be altered by arteriosclerosis. Consequently, their association with CAD would permit to imply causality. We modeled by regression analysis the effect of 11 variants in the methionine cycle upon CAD manifestation in 591 controls and 278 CAD patients. Among the examined variants only the carriership for the c.844ins68 in the cystathionine beta-synthase (CBS) gene was associated with a significantly lowered risk of CAD (OR=0.56; 95% CI=0.35-0.90 in the univariable, and OR=0.41, 95% CI=0.19-0.89 for obese people in the multivariable analysis, respectively). Healthy carriers of the c.844ins68 variant exhibited, compared to the wild type controls, significantly higher postload ratios of blood S-adenosylmethionine to S-adenosylhomocysteine (61.4 vs. 54.9, p=0.001) and of plasma total cysteine to homocysteine (8.6 vs. 7.3, p=0.004). The changes in these metabolites are compatible with an improved methylation status and with enhanced activity of homocysteine transsulfuration. In conclusion, the coincidence of clinical and biochemical effects of a common c.844ins68 CBS variant supports the hypothesis that compounds relating to homocysteine metabolism may play role in the development and/or progression of CAD.

Initial experience with a short, tension-free vaginal tape (the tension-free vaginal tape secur system)

OBJECTIVE The aim of this study is to present our first experience with a novel modification of the tension-free sling idea and to evaluate the safety and efficacy of this new procedure for the treatment of stress urinary incontinence in women. STUDY DESIGN Eighty-five women with previously untreated stress urinary incontinence were recruited to participate in a clinical study. The efficacy of this surgical procedure was evaluated perioperatively and 3 months (+/-1 week) after operation--objectively by cough test and subjectively by the questionnaires Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire and the International Consultation on Incontinence Questionnaire-Short Form. All data were processed and statistical analyses performed in statistical environment R, version 2.5.1. RESULTS From our results we conclude that there were no perioperative complications, objectively 62% of these patients were completely dry and 25% of patients improved. We observed a higher proportion of vaginal wall erosion (7/85) and urgency de novo (5/85) in the learning period group with respect to the routine period group. CONCLUSIONS Our first experience with the tension-free vaginal tape secur system procedure is that it has a low percentage of perioperative complications. The learning curve has to be taken in account with reference to postoperative complications.

Rare Allelic Variants Determine Folate Status in an Unsupplemented European Population

The role of folates as coenzymes in 1-carbon metabolism and the clinical consequences of disturbed folate metabolism are widely known. Folate status is a complex trait determined by both exogenous and endogenous factors. This study analyzed the association between 12 genetic variants and folate status in a Czech population with no folate fortification program. These 12 genetic variants were selected from 56 variant alleles found by resequencing the coding sequences and adjacent intronic regions of 6 candidate genes involved in folate metabolism or transport (FOLR1, FOLR2, FOLR3, MTHFR, PCFT, and RFC) from 29 individuals with low plasma and erythrocyte folate concentrations. Regression analyses of a cohort of 511 Czech controls not taking folate supplements revealed that only 2 variants in the MTHFR gene were associated with altered folate concentrations in plasma and/or erythrocytes. In our previous study, we observed that the common variant MTHFR c.665C > T (known as c.677C > T; p.A222V) was associated with decreased plasma folate concentrations. In the present study, we show in addition that the rare variant MTHFR c.1958C > T (p.T653M) is associated with significantly increased erythrocyte folate concentrations (P = 0.02). Multivariate regression analysis revealed that this uncommon variant, which is present in 2% of Czech control chromosomes, explains 0.9% of the total variability of erythrocyte folate concentrations; the magnitude of this effect size was comparable with that of the common MTHFR c.665C > T variant. This result indicates that the rare genetic variants may determine folate status to a similar extent as the common allelic variant.