TABLE 4.

FAMILY-BASED ANALYSIS OF POTENTIAL MODIFICATION OF THE EFFECT OF TGFB1 POLYMORPHISMS ON ASTHMA-RELATED OUTCOMES BY DUST MITE ALLERGEN EXPOSURE^*

		Costa Rica Stratified Analysis			CAMP Stratified Analysis
Phenotype	SNP (Allele)	Unexposed (51%)	Exposed (49%)	Costa Rica Interaction P Value	Unexposed (91%)	Exposed (9%)	CAMP Interaction P Value
Airway responsiveness	rs1800471 (C)	NS†	+0.02‡	0.03	NS	+0.03	0.03
Asthma exacerbations	rs2241712 (A)	NS	+0.001	0.008	NS	+0.03	0.03

Definition of abbreviations: NS = nonsignificant; SNP = single nucleotide polymorphism.

^*Der p 1 levels in house dust (dust mite allergen exposure) were dichotomized at ≥10 μg/g. The proportion of unexposed/exposed children was similar for each single nucleotide polymorphism in a given cohort.

^†NS = P > 0.05.

^‡Plus sign represents increased airways responsiveness or increased exacerbations after high exposure to dust mite.