The genetics of sleep apnea.

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a complex chronic condition that is undoubtedly influenced by multiple factors. Accumulating data suggest that there are strong genetic underpinnings for this condition. It has been estimated that approximately 40% of the variance in the apnea hypopnea index (AHI) may be explained by familial factors. It is likely that genetic factors associated with craniofacial structure, body fat distribution and neural control of the upper airway muscles interact to produce the OSAHS phenotype. Although the role of specific genes that influence the development of OSAHS have not yet been identified, current research in rodents suggests that several genetic systems may be important. In this chapter, we shall first define the OSAHS phenotype, and then review the evidence that suggests an underlying genetic basis of OSAHS, the risk factors for OSAHS that may be inherited, and potential candidate genes.