Gantner ML, Eade K, Wallace M, et al. - Through exome sequence analysis of an individual with macular telangiectasia type 2 and his family members, experts recognized a variant in SPTLC1 encoding a subunit of serine palmitoyltransferase (SPT). Ten supplementary individuals with HSAN1 for the ophthalmologic disease were investigated. Risk factors for macular telangiectasia type 2 as well as for peripheral neuropathy were found out to be raised levels of atypical deoxysphingolipids, caused due to variant SPTLC1 or SPTLC2 or by low serine levels.