SPTLC2 and amyotrophic lateral sclerosis: Reduced serum levels of serine and increased 1-deoxySL have been previously noted in patients with macular telangiectasia type 2 (with or without associated SPT component pathogenic variants).30 However, our patients with E260K SPTLC2 related ALS phenotype did not show any clinical signs of macular involvement at the time of evaluation.