Heme/Onc4

Question 1

A newborn develops multiple hemorrhages. Lab studies show an elevated prothrombin time (PT). What process is most likely abnormal in this newborn?

Answer 1

This baby likely has a vitamin K deficiency, and has developed hemorrhagic disease of the newborn.

Glutamate residues on factors 2, 7, 9, and 10must be gamma-carboxylated (in a reaction that requires vitamin K) in order for these factors to be activated.