PDE5A and ablepharon macrostomia syndrome: Notably, two genes, HBA1, PDE5A, exhibited significant increases during acute ascent to HA in AMS + individuals (AMS + SL vs. AMS + HA), and their expression levels were also significantly higher in AMS + individuals compared to AMS─ individuals, both at SL (AMS + SL vs. AMS─SL) and HA (AMS + HA vs. AMS─ HA) (Figure 4).