The TENM3 gene encodes a transmembraneprotein of 2699 amino acids that is expressed in adult and fetal brain, slightly lower levels in testis and ovary, and intermediate levels in all other peripheral tissues.  It may be involved in neural development, regulating the establishment of proper connectivity within the nervous system.  It also plays a role in the development of the visual pathway.  Defects in this protein have been associated with microphthalmia, isolated, with coloboma 9, a disorder of eye formation, ranging from small size of a single eye to complete bilateral absence of ocular tissues.