Hermansky-Pudlak Syndrome (HPS) is a type of albinism which includes a bleeding tendency, colitis, lung disease, and kidney disease. The severity of these problems varies much from person to person. It is not easily diagnosed with usual types of blood tests. One of the most troubling aspects of HPS is that its onset, severity and course is unpredictable. The severity of bleeding problems varies much in HPS, from minor bruising to life-threatening haemorrhage. Some children have had bleeding problems from minor surgery such as placement of ear tubes. The colitis usually does not develop until adolescence, though in several cases it has appeared in infants. The lung disease may not develop until adulthood.
The bleeding problems of Hermansky Pudlak Syndrome result from a malfunction of platelets, the tiny blood cells that clump together to plug up damaged blood vessels in cuts, scrapes, and bruises. The platelets lack dense bodies, which are tiny storehouses of the chemicals which platelets need to stay clumped together.
The cause of the intestinal and lung problems seems to have something to do with a "ceroid" or yellowish material which is found in many different organs of people with HPS. Research has not yet found the exact nature of this material. Newer research has found high levels of a substance called platelet derived growth factor in the lungs of people with HPS, and also in those who carry the gene for HPS. This substance may cause the pulmonary fibrosis.
Although HPS has been identified most frequently among Puerto Ricans, the syndrome occurs all over the world. It was first recognized in two Czechoslovakian individuals in 1959. It should be suspected in any child with albinism who shows easy bruising or unusual bleeding, such as repeated nosebleeds or bloody diarrhea.