- Apolipoprotein gene cluster on chromosome 19. Definite localization of the APOC2 gene and the polymorphic Hpa I site associated with type III hyperlipoproteinemia. Smit, M., van der Kooij-Meijs, E., Frants, R.R., Havekes, L., Klasen, E.C. Hum. Genet. (1988)