B2 Adrenergic Receptor

Four polymorphisms of the coding block of b2 adrenergic receptor (b2AR) have been found, three of which result in receptors that have different properties compared with the wild-type (73). These polymorphisms include Arg16! Gly, Gln27 ! Glu, Val34 ! Met, and Thr164 ! Ile, of which the first two are the most common. Most studies have found no differences in the frequencies of these polymorphisms between asthma patients and healthy nonasthmatic controls (74,75). Thus, the genetic variability of the b2AR does not appear to play a major causative role in asthma. However, these polymorphisms, although not causative, could modify the disease. Other studies have assessed the relationship between b2AR polymorphisms at positions 16 and 27 and atopy, including IgE levels (76). A significant association between the Glu27 form of the b2 receptor and log serum IgE was reported, suggesting that b2AR polymorphisms may act to modify the asthmatic phenotype (77).

Several studies have assessed the modulatory role of b2AR polymorphisms on the treatment response to b-agonists (2,78) in relation to bronchial hyperreactivity (79) and control of asthma (80). These studies demonstrate that certain b2AR polymorphisms affect the clinical response to b-agonist therapy, which may impact the asthmatic pheno-type, rendering these variants candidates that may ultimately provide for individualized therapy in asthma.

Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

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