Surfactant protein A and B genetic variants and respiratory distress syndrome: Allele interactions

The contribution of multiple genetic components in disease pathogenesis is relevant to both diseases of multifactorial and/or multigenic etiology such as the respiratory distress syndrome (RDS) and to diseases where a single gene has been identified as the disease-causing gene. An example of the latter is cystic fibrosis (CF) where the disease-causing gene has been clearly identified as the CF transmembrane conductance regulator gene, but genetic variants of the mannose binding protein and surfactant protein A have been associated with disease severity in CF. The overall rationale for considering genetic contribution to disease pathogenesis is based on the premise that all diseases or deaths (except perhaps those resulting from trauma) have a genetic component. The difference in genetic contribution among various diseases is the percent contribution and the number of factors that make this contribution. Therefore, if the number of genetic contributors is small and the percentage of genetic contribution is high it may be less challenging to identify such factors. In this paper we summarize allele associations and discuss allele interaction of the surfactant protein genes in relation to RDS (the term allele and genetic variant will be used interchangeably).