Association of a chromosome 1q21 locus in close proximity to a late cornified envelope-like proline-rich 1 (LELP1) gene with total serum IgE levels.

The chromosomal region 1q21 has been linked to atopic dermatitis in previous studies. Seven polymorphic repeats were identified in a 0.5 Mb region of chromosome 1q21 encompassing a small proline-rich protein (SPRR) gene cluster, a few S100 gene family members, loricin, and several uncharacterized genes. These repeats were genotyped by fragment length polymorphism analysis in 133 atopic case-parent trios, of which 111 probands had atopic asthma. Our trio-based analysis for association with atopy and atopic asthma revealed no significant allelic or genotypic association for any of the seven loci tested. However, a significant association was observed with locus 5 (3.65 Mb of contig NT_032962) and log(10) serum IgE levels (F = 3.93, P = 0.0008). Results were also replicated in an independent case-control cohort (N (p) = 165, N (c) = 166), where a significant association with log(10) serum IgE levels was observed in the patient group (P = 0.0005). Interestingly, locus 5 is 6.2 kb upstream of a late cornified envelope-like proline-rich 1 (LELP1) gene which encodes a novel small proline rich protein. Further, we have also found a significant association of rs7534334 (tagged SNP from LELP1) SNP with log(10) serum IgE levels in the patient group (P = 0.0029). Thus, our results identify a chromosomal region in close proximity to a novel gene and highlight the need for intense research on LELP1 and other genes close by with respect to atopic disorders.