Association of beta-defensin 1 single nucleotide polymorphisms with atopic dermatitis.
BACKGROUND
Atopic dermatitis (AD) is a chronic multifactorial allergic disease with unclear etiology. The antimicrobial human beta-defensin 1 is chemotactic for dendritic cells, which are important regulators of allergic immune responses. In an attempt to identify useful markers that could predict susceptibility to AD, we investigated single nucleotide polymorphisms (SNPs) of the beta-defensin 1 gene (DEFB1) with potential functional consequences.


METHODS
Four SNPs of the DEFB1 gene were genotyped either by real-time polymerase chain reaction or polymerase chain reaction-restriction fragment length polymorphisms in 59 patients with AD and 151 controls from the Mexican population. Correlation analyses were carried out between genetic, environmental and clinical variables in AD patients.


RESULTS
The genotypes associated with susceptibility to AD and no other allergy were 692 GG (OR = 3.21, 95% CI 1.37-7.34) and 1654 AA (OR = 17.37, 95% CI 1.62-860.83). The allele 668 C is a risk factor for AD (OR = 2.23, 95% CI 1.22-4.01) and the allele A in site 1836 correlates with earlier age at onset (Spearman's rho = 0.232; p = 0.03). The prolonged duration of breastfeeding correlates with earlier age at onset as well as with the severity of AD.


CONCLUSIONS
The DEFB1 gene is probably involved in the incidence and development of AD, but additional functional studies will be necessary to understand the biological role of these SNPs.
Prado-Montes de Oca
Ernesto
E
PhD Program in Human Genetics, Universidad de Guadalajara, Guadalajara, Jalisco, México.
García-Vargas
Alejandro
A
Lozano-Inocencio
Reymundo
R
Gallegos-Arreola
Martha Patricia
MP
Sandoval-Ramírez
Lucila
L
Dávalos-Rodríguez
Nory Omara
NO
Figuera
Luis Eduardo
LE
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D015810:Linkage Disequilibrium; D008297:Male; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023083:beta-Defensins / Q000235:genetics*
C406407:DEFB1 protein, human; D023083:beta-Defensins