This domain is found on phosphatidylinositol n-acetylglucosaminyltransferase proteins. These proteins are involved in GPI anchor biosynthesis and are associated with disease the paroxysmal nocturnal haemoglobinuria [1].

1: The effect of GPI-anchor deficiency on apoptosis in mice carrying a Piga gene mutation in hematopoietic cells. Kulkarni S, Bessler M; J Leukoc Biol 2002;72:1228-1233. PMID:12488505