A U wave as seen on ECG. An electrocardiogram of an 18-year-old man showing U waves, most evident in lead V3. The U wave is a wave on an electrocardiogram that is not always seen. It is typically small, and, by definition, follows the T wave. U waves are thought to represent repolarization of the papillary muscles or Purkinje fibers.
HCP is caused by mutations in the CPOX gene, which codes for the enzyme coproporphyrinogen oxidase. This enzyme is responsible for the sixth step in the heme biosynthetic pathway, converting coproporphyrinogen III to protoporphyrinogen IX.
This. means that affected persons are heterozygous, such that each offspring. of a patient with FAP has a 50% chance of inheriting the disease. gene. The gene responsible for FAP is known as APC (for adenomatous. polyposis coli) and is located on chromosome 5q2l [1-2,10].Mutations of the APC gene have been found in patients with FAP. (eg, 2,11).f a patient with FAP has a 50% chance of inheriting the disease. gene. The gene responsible for FAP is known as APC (for adenomatous. polyposis coli) and is located on chromosome 5q2l [1-2,10].