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Background Recently, three genome-wide association studies ( GWAS) demonstrated FCER1 A, the gene encoding a ligand-binding subunit of the high-affinity Ig E receptor, to be a major susceptibility locus for serum Ig E levels. The top association signal differed between the two studies from the general population and the one based on an asthma case-control design. In this study, we investigated whether different FCER1 A polymorphisms are associated with total serum Ig E in the general population and asthmatics specifically. Methods Nineteen polymorphisms were studied in FCER1 A based on a detailed literature search and a tagging approach. Polymorphisms were genotyped by the Illumina Human Hap300 Chip (6 polymorphisms) or MALDI- TOF MS (13 polymorphisms) in at least 1303 children (651 asthmatics) derived from the German International Study of Asthma and Allergies in Childhood II and Multicentre Asthma Genetics in Childhood Study. Results Similar to two population-based GWAS, the peak association with total serum Ig E was observed for SNPs rs2511211, rs2427837, and rs2251746 (mean r 2 > 0.8), with the lowest p-value of 4.37 × 10−6. The same 3 polymorphisms showed the strongest association in non-asthmatics (lowest p = 0.0003). While these polymorphisms were also associated with total serum Ig E in asthmatics (lowest p = 0.003), additional polymorphisms (rs3845625, rs7522607, and rs2427829) demonstrated associations with total serum Ig E in asthmatics only (lowest p = 0.01). Conclusions These data suggest that FCER1 A polymorphisms not only drive Ig E levels in the general population but that specific polymorphisms may also influence Ig E in association with asthma, suggesting that disease-specific mechanisms in Ig E regulation exist. [ABSTRACT FROM AUTHOR]

The dopamine transporter (DAT1) is a membrane spanning protein that binds the neurotransmitter dopamine and performs re-uptake of dopamine from the synapse into a neuron. The gene encoding DAT1 consists of 15 exons spanning 60 kb on chromosome 5p15.32. Several studies have investigated the possible associations between variants in DAT1 gene and psychiatric disorders. The present study aimed to determine the distribution of the variable number of tandem repeat (VNTR) polymorphism in the 3′ untranslated region of DAT1 in 12 Indian populations. A total of 471 healthy unrelated individuals in 12 Indian populations from 3 linguistic groups were included in the present study. The analysis was carried out using PCR and electrophoresis. Overall, 4 alleles of the DAT1 40-bp VNTR, ranging from 7 to 11 repeats were detected. Heterozygosity indices were low and varied from 0.114 to 0.406. The results demonstrate the variability of the DAT1 40-bp VNTR polymorphism in Indian populations and revealed a high similarity with East Asian populations. [ABSTRACT FROM AUTHOR]