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- Börjel, Anna K., et al.
(author)
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Novel mutations in the 5'-UTR of the FOLR1 gene
- 2006
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In: Clinical Chemistry and Laboratory Medicine. - 1434-6621 .- 1437-4331. ; 44:2, s. 161-167
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Journal article (peer-reviewed)abstract
- We have previously reported two novel mutations in the 5'-untranslated region (UTR) of the gene for folate receptor-alpha (FOLR1). In our search for additional mutations, 92 patient samples with elevated levels of homocysteine were screened by single-strand conformation polymorphism (SSCP) between nt -425 and -782, and -712 and -1110. Between nt -425 and -782 we did not find any mutations. Between nt -712 and -1110 there were three novel mutations. One subject had two mutations very close to each other, c.-856C>T and c.-921T>C. Two subjects had a c.-1043G>A mutation. To get an idea of the prevalence of FOLR1 mutations in an unselected population, we also screened 692 healthy school children for mutations. In this cohort, between nt -188 and +272 we discovered one novel mutation, a single nucleotide substitution, c.-18C>T, in addition to five children with the 25-bp deletion mutation previously described by us. Thus, so far we have discovered six novel mutations in the 5'-UTR region of the gene for folate receptor-alpha. We genotyped all 17 subjects with a FOLR1 mutation for the methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism, and developed new single-nucleotide polymorphism (SNP) genotyping protocols for MTHFR 1298A>C and 1793G>A utilising Pyrosequencing technology. None of the 17 subjects had the 677TT genotype, which ruled out this as a cause of elevated homocysteine levels, which was observed in some of the subjects. Further studies of mutations in the 5'-UTR of FOLR1, and in particular of their interplay with folate intake status, are warranted.
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| 2. |
- Böttiger, Anna K., 1977-, et al.
(author)
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Association of total plasma homocysteine with methylenetetrahydrofolate reductase genotypes 677C > T, 1298A > C, and 1793G > A and the corresponding haplotypes in Swedish children and adolescents
- 2007
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In: International Journal of Molecular Medicine. - Athens, Greece : D.A. Spandidos. - 1107-3756 .- 1791-244X. ; 19:4, s. 659-665
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Journal article (peer-reviewed)abstract
- We studied 692 Swedish children and adolescents (aged 9-10 or 15-16 years, respectively), in order to evaluate the effect of the methylenetetrahydrofolate reductase (MTHFR) 677C > T, 1298A > C, and 1793G > A polymorphisms on total plasma homocysteine concentrations (tHcy). Genotyping was performed with Pyrosequencing (TM) technology. The MTHFR 677C > T polymorphism was associated with increased tHcy concentrations in both the children and the adolescents (P < 0.001 for both age groups) in both genders. The effect of MTHFR 1298A > C was studied separately in subjects with the 677CC and 677CT genotypes, and the 1298C allele was found to be associated with higher tHcy levels both when children were stratified according to 677C > T genotypes, and when using haplotype analyses and diplotype reconstructions. The 1793A allele was in complete linkage disequilibrium with the 1298C allele. It was still possible to show that the 1793A allele was associated with lower tHcy levels, statistically significant in the adolescents. In conclusion, a haplotype-based approach was slightly superior in explaining the genetic interaction on tHcy plasma levels in children and adolescents than a simple genotype based approach (R-2 adj 0.44 vs. 0.40). The major genetic impact on tHcy concentrations is attributable to the MTHFR 677C > T polymorphism. The common 1298A > C polymorphism had a minor elevating effect on tHcy, whereas the 1793G > A polymorphism had a lowering effect on tHcy.
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| 4. |
- Sanner, Karin, 1961-, et al.
(author)
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Ovarian epithelial neoplasia after hormonal infertility treatment: long-term follow-up of a historical cohort in Sweden
- 2009
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In: Fertil Steril. - : Elsevier BV. ; 91:4, s. 1152-1158
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To study the association between hormonal infertility treatment and ovarian neoplasia. DESIGN: Historical cohort study. SETTING: Three university hospitals in Sweden. PATIENT(S): A total of 2,768 women assessed and treated for infertility and infertility-associated disorders between 1961 and 1975. INTERVENTION(S): Exposed women received clomiphene citrate and/or gonadotropins. MAIN OUTCOME MEASURE(S): Incidence of ovarian neoplasia. RESULT(S): No overall excess risk of invasive ovarian cancer emerged compared with the general population. In women with gonadotropin treatment for non-ovulatory disorders, the risk was elevated (standardized incidence ratio [SIR] = 5.89; 95% confidence interval [CI] 1.91-13.75); four of the five cases reported hCG treatment only, rendering the biological plausibility uncertain. Multivariate analysis within the cohort indicated that treatment with gonadotropins only was associated with an increased risk of invasive cancer (relative risk = 5.28; 95% CI 1.70-16.47). For borderline tumors, a more than threefold overall increase of tumors (SIR = 3.61; 95% CI 1.45-7.44) was noted; women exposed to clomiphene because of ovulatory disorders showed the highest risk (SIR = 7.47; 95% CI 1.54-21.83). CONCLUSION(S): Our findings of increased risk of ovarian cancer after gonadotropins and of borderline tumors after clomiphene treatment need to be interpreted with caution. However, concern is raised, and further research on the long-term safety particularly of modern hormonal infertility treatment in IVF programs is warranted.
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| 5. |
- Svane, Maria, 1957, et al.
(author)
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On-Line Chemical Analysis of Individual Alkali-Containing Aerosol Particles by Surface Ionization Combined with Time-of-Flight Mass Spectrometry
- 2009
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In: Aerosol Science and Technology. - : Informa UK Limited. - 0278-6826 .- 1521-7388. ; 43:7, s. 653-661
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Journal article (peer-reviewed)abstract
- An aerosol mass spectrometer for measurements of the alkali metal content in individual submicron aerosol particles is presented. The instrument combines surface ionization of individual particles on a hot platinum surface with orthogonal acceleration time-of-flight mass spectrometry. The instrument simultaneously provides the content of different alkali metal elements in single particles with high sensitivity. The instrument is characterized in laboratory experiments, and determination of the alkali metal content is demonstrated for particle diameters of 50-500 nm. The technique is demonstrated in ambient air measurements at an urban background site, and sea spray particles and particles originating from biomass burning are identified based on their content of sodium and potassium. Possible further improvements and applications of the technique are discussed.
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