Article

Variants of the FADS1 FADS2 Gene Cluster, Blood Levels of Polyunsaturated Fatty Acids and Eczema in Children within the First 2 Years of Life

Ludwig-Maximilians-Universität München, Germany
PLoS ONE (Impact Factor: 3.23). 10/2010; 5(10):e13261. DOI: 10.1371/journal.pone.0013261
Source: PubMed

ABSTRACT

Association of genetic-variants in the FADS1-FADS2-gene-cluster with fatty-acid-composition in blood of adult-populations is well established. We analyze this genetic-association in two children-cohort-studies. In addition, the association between variants in the FADS-gene-cluster and blood-fatty-acid-composition with eczema was studied.
Data of two population-based-birth-cohorts in The Netherlands and Germany (KOALA, LISA) were pooled (n = 879) and analyzed by (logistic) regression regarding the mutual influence of single-nucleotide-polymorphisms (SNPs) in the FADS-gene-cluster (rs174545, rs174546, rs174556, rs174561, rs3834458), on polyunsaturated fatty acids (PUFA) in blood and parent-reported eczema until the age of 2 years. All SNPs were highly significantly associated with all PUFAs except for alpha-linolenic-acid and eicosapentaenoic-acid, also after correction for multiple-testing. All tested SNPs showed associations with eczema in the LISA-study, but not in the KOALA-study. None of the PUFAs was significantly associated with eczema neither in the pooled nor in the analyses stratified by study-cohort.
PUFA-composition in young children's blood is under strong control of the FADS-gene-cluster. Inconsistent results were found for a link between these genetic-variants with eczema. PUFA in blood was not associated with eczema. Thus the hypothesis of an inflammatory-link between PUFA and eczema by the metabolic-pathway of LC-PUFAs as precursors for inflammatory prostaglandins and leukotrienes could not be confirmed by these data.

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    • "Schaeffer et al found that adult minor allele carriers of several SNPs had a lower prevalence of self‐reported allergic rhinitis and atopic eczema [44]. Rzehak et al found that minor allele carriers of several SNPS in the FADS gene cluster had a higher prevalence of parental reported eczema at 2 years of age in the LISA‐ study, while no associations were found in the KOALA‐study [48]. Two studies found no association between 5 SNPs in FADS1/FADS2 and asthma, bronchitis, eczema or hay fever at 6 years of age [58] or at 10 years of age [59] in subjects from the two German LISA and GINI birth cohorts. "
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    • "As expected, the fatty acid profile of the plasma from subjects homozygous for the FADS2 rs 3834458 deletion [−/−] differed substantially from that of the other genotypes in that proportions of plasma total eicosapentaenoic acid (20:5 n-3), docosapentaenoic acid (22:5 n-3) and arachidonic acid (20:4 n-6) were significantly decreased. These findings are in line with earlier observations [3,8,9]. However, only about 8% of the dietary linoleic acid / α-linolenic acid go through the elongase/desaturase biosynthetic pathway to eicosapentaenoic acid and conversion to docosahexaenoic acid is extremely low (<0.1%) "
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