Association of epidermal differentiation complex (EDC) genetic variants with House Dust Mite sensitization in Atopic...

The etiopathogenesis of AD is multifactorial and defects of the skin barrier, which physiologically constitutes the natural protection, are associated with the disease phenotype. The identification of the genetic and environmental factors paving the way for impaired barrier function is therefore important in developing new therapeutic and prevention strategies.

Confirmed 100 cases were tested against 106 controls for filaggrin mutation and LELP-1 polymorphism by PCR-RFLP and chain termination sequencing. Total IgE and Vitamin D were estimated by ELISA. House dust mite sensitization was assessed by an in-vivo skin prick test.

FLG deletion (2282del4) was present in 4% of the patients and all these were heterozygous carriers, whereas FLG null mutation (R501X) was not present in any of the cases. In the control group, both the mutations were not found. CT genotype and T allele of LELP-1 (rs7534334) were significantly associated with elevated IgE levels, early-onset, HDM sensitization, and disease severity (P < 0.05). However, the genotypic and allelic distribution of LELP-1 among the cases and controls was found to be insignificant.

The low frequency of 2282del4 deletion and the absence of R501X mutation suggest that filaggrin deficiency does not confer a major risk for AD in the Indian population. However, significant association of LELP-1 (rs7534334) variant allele with clinical variables may serve as a novel biomarker for the severity of Atopic Dermatitis as well as an indicator for the allergen-specific immunotherapy and hence bears important clinical implications and needs to study on larger sample size and diverse populations.