The prevalence of asthma varies across different ethnic groups, and has been found to be greater in specific ethnicities. Researchers lead by Dr. Dan Nicolae from the University of Chicago have found that a polymorphism in one particular gene called PYHIN1 is more common in African American and African Caribbean asthmatic patients. The results of their study were published online in the journal Nature Genetics. This particular gene variant is almost non-existent in European American asthmatics and occurs in less than 5% of Latin American asthmatics. This finding may explain the observed greater occurrence of asthma among individuals of African descent. The researchers used data from nine previous genome-wide association studies, known as the EVE Consortium, for their meta-analysis. The meta-analysis evaluated over 2 million single nucleotide polymorphisms in asthmatics, non-asthmatics, and their family members. The researchers used three groups for their analysis and these included European Americans, Latin Americans, and African Americans and African Caribbeans. The researchers identified one polymorphism in the gene for PYHIN1 which was present in 34% of asthmatics of African American or African Caribbean descent. The authors wrote, “This family of genes has been previously associated with autoimmunity, but to date, PYHIN1 has not been implicated in asthma pathogenesis… We anticipate that ongoing studies in the EVE Consortium datasets will identify other loci contributing to asthma risk and ultimately provide a better understanding of the molecular pathways and networks that are common to the risk architecture of asthma in diverse populations and those that are specific to certain groups”. It is important to note that the findings of this study identify an association for asthma susceptibility but they do not necessarily identify a causal relationship for PYHIN1 in asthma.
Dara G. Torgerson et al. “Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations” Nature Genetics published online July 31, 2011 doi:10.1038/ng.888