ADRB2 and asthma: A cadherin-related family member gene variant (CDHR-3) has been linked to recurrent severe asthma exacerbations in preschool children of European descent [125], while the 17q21 locus and the ADRB2 gene (especially its Glu27 variant) are consistently associated with asthma attacks in asthmatic children and adults [5,126].