GPD1L, also known as glycerol-3-phosphate dehydrogenase 1-like protein, converts sn-glycerol 3- phosphate to glycerone phosphate. This protein is found in the cytoplasm, associated with the plasma membrane, where it binds the sodium channel, voltage-gated, type V, alpha subunit (SCN5A). Mutations in GPD1L are the cause of sudden infant death syndrome (SIDS) and Brugada syndrome type 2, an autosomal dominant tachyarrhythmia.