Recently, a genome-wide association study (GWAS) of cognition in Japanese patients with schizophrenia (SCZ) found that impairment was associated with a non-synonymous single-nucleotide polymorphism (SNP, rs7157599, Asn8Ser) in the delta(4)-desaturase, sphingolipid 2 (DEGS2) gene.3 A replication analysis using Caucasian samples showed a directionally consistent trend for cognitive association of a proxy SNP (rs3783332: r2=0.76) in high linkage disequilibrium (LD) with rs7157599 (Supplementary Figure 1). This evidence concerns the gene DEGS2 and schizophrenia.