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.
Definition of Hereditary mixed polyposis syndrome. Hereditary mixed polyposis syndrome: (HMPS) A cancer family syndrome characterized by the development of a variety of different types of polyps in the colon, including atypical juvenile polyps and adenomas of the colon, and by the development of colorectal carcinoma (cancer of colon and rectum). HMPS is inherited in an autosomal dominant manner. The HMPS gene locus is on chromosome 15 in region 15q13-q14. HMPS is also known as colorectal adenoma and carcinoma 1 (CRAC1). It has been uncertain whether HMPS is a distinct disorder or a variant of an established disease called juvenile polyposis.