SPTLC1 and amyotrophic lateral sclerosis: Patient 3 carried a p.Ser331Tyr (chr9:94809543G>T) heterozygous variation in SPTLC1. Screening of the SPTLC1 gene in a cohort of 63 patients with juvenile ALS from Turkey who had undergone whole-exome sequencing identified a p.Leu39del (chr9:94874785_94874787del) heterozygous variant in patient 4 (Figure 2D).