Hsieh et al. (2010) did not find any increase in incidence of RISP in patients with OSA compared to those without OSA (Hsieh et al., 2010). This suggests that the presence of OSA did not lead to RISP, even though that might lead to disturbed sleep quality and continuity; another co-factor that is related to RISP (Hsieh et al., 2010). This evidence concerns the gene UQCRFS1 and obstructive sleep apnea syndrome.