Genome-wide analysis of all autosomal genes produced one significant finding for both endophenotypes that survived Bonferroni correction. Myelin expression factor 2 (MYEF2) is a transcriptional repressor of myelin basic protein, which codes for a major constituent of the myelin sheath surrounding oligodendrocytes and Schwann cells in the central nervous system. In addition to increasing the velocity of the conduction of action potentials along axons, myelin is important for facilitating long-range connections among brain regions. P3 appears to be produced by a distributed neural circuit, and myelin may facilitate coherent activity in this circuit. This is a novel finding, although we are unable to find any previous links to P3 or related measures, which makes independent replication especially important.
