Surprisingly, in the current study, subjects using ALK to screen for SDB appeared to be not as reliable as in a previous study [15] (AUC were 0.79 vs. 0.86 and 0.82 vs. 0.98 in the current study vs. the previous study on the thresholds of 5 and 15 events/hr in AHIpsg values, respectively). This evidence concerns the gene ALK and sleep apnea syndrome.