Genetic association studies between the T cell immunoglobulin mucin (TIM) gene locus and childhood atopic dermatitis.
BACKGROUND
The T cell immunoglobulin mucin (TIM) gene family is involved in T cell proliferation and differentiation and has been implicated in allergic disease. We have tested whether TIM gene polymorphisms are associated with atopic dermatitis (AD) in an Australian cohort.


METHODS
Transmission disequilibrium testing of 15 single nucleotide polymorphisms across TIM-1, TIM-3 and TIM-4 in 93 Caucasian families, and of a tri-allelic (0, 15 and 18 base pairs) TIM-1 insertion polymorphism in 123 Caucasian and Asian families, was carried out in proband-parent trio families.


RESULTS
Transmission of the 18-base pair variant of this insertion was significantly under-represented in the childhood AD cohort (p = 0.02), which is in agreement with a previous study on asthma in an African-American cohort. We also found a novel association between AD and the major haplotype of TIM-4 (p = 0.016). There was no evidence for an association between AD and TIM-3.


CONCLUSIONS
In addition to confirming the importance of genetic variation in TIM-1, our results also suggest that genetic variants in the ligand for TIM-1, TIM-4, also contribute to the presentation of AD and related disorders.
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Natalie S
NS
Institute for Immunology and Allergy Research, Westmead Millennium Institute, University of Sydney, Westmead Hospital, Westmead, Australia. natalie_hartley@wmi.usyd.edu.au
Jones
Graham
G
Stewart
Graeme J
GJ
D002648:Child; D002874:Chromosome Mapping; D003876:Dermatitis, Atopic / Q000235:genetics*; D005787:Gene Frequency; D006239:Haplotypes; D000072596:Hepatitis A Virus Cellular Receptor 1; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D011991:Receptors, Virus / Q000235:genetics*
C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011991:Receptors, Virus; C512411:TIMD4 protein, human