SGMS1 and amyotrophic lateral sclerosis: Sphingomyelin synthase 1 (SGMS1) and acid sphingomyelinase (SMase) are involved in the metabolism of ceramide to sphingomyelin; SGMS1 expression was significantly higher in ALS compared to control (Figure 6f; p = 0.03), but there was no difference in SMPD1 (encodes SMase; Figure 6g; p = 0.78) expression.