SELENOS and pontocerebellar hypoplasia type 2D: Wirth and colleagues also noted striking parallels between their Trsp mutant mice and human patients with pontocerebellar hypoplasia type 2D (PCH2D, OMIM #613811), a syndrome caused by deleterious variants in the SEPSECS gene, which encodes a protein essential to selenoprotein biosynthesis [49,54,55].