Additional Reading:

Headon, D. 2015.  PLoS Genetics 11:e1004979. Morphological mutations: Lessons from the cockscomb.  The gene and the mutations that give rise to the phenotypes in Problem 8-23

Yamamoto, F-I, et al. 1990.  Molecular basis of the histo-blood group ABO system. Nature 345: 229-233