POMT2 is an integral membrane protein of the endoplasmic reticulum (ER) that shares significant sequence similarity with a family of protein O-mannosyltransferases of S. cerevisiae.

Defects in POMT2 are a cause of Walker-Warburg syndrome (WWS); also known as hydrocephalus-agyria-retinal dysplasia or HARD syndrome. WWS is an autosomal recessive disorder characterized by cobblestone lissencephaly, hydrocephalus, agyria, retinal displasia, with or without encephalocele. It is often associated with congenital muscular dystrophy and usually lethal within the first few months of life.