Causes
HPS can be caused by mutations in several genes: HPS1, HPS3, HPS4, HPS5, HPS6 and HPS7.HPS type 2, which includes immunodeficiency in its phenotype, is caused by mutation in the AP3B1 gene.HPS type 7 may result from a mutation in the gene coding for dysbindin protein.Hermansky–Pudlak syndrome is thought to be inherited as an autosomal recessive genetic trait. The defective gene, called HSP, responsible for this disorder is located on the long arm of chromosome 10 (10q2). Some research suggests that an abnormality of lysosomal function may be responsible for the development of the disease. HPS1, AP3B1, HPS3, HPS4, HPS5, HPS6, DTNBP1 and  Biogenesis of Lysosome-related Organelles Complex (BLOC1, BLOC1S2 and BLOC3) are associated with Hermansky–Pudlak syndrome.In autosomal recessive disorders, the condition does not appear unless a person inherits two copies of the defective gene responsible for the disorder, one copy coming from each parent. If an individual receives one normal gene and one gene for the disorder, the person will be a carrier for the disease, but usually will not show symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is 25 percent. Fifty percent of their children risk being carriers of the disease, but generally will not show symptoms of the disorder. Twenty-five percent of their children may receive both normal genes, one from each parent, and will be genetically normal (for that particular trait). The risk is the same for each pregnancy.
Prolonged bleeding
has been reported following strabismus surgery in patients with the syndrome. Prognosis
The course of HPS has been mild in rare instances of the disorder, however, the general prognosis is still considered to be poor.The disease can cause dysfunctions of the lungs, intestine, kidneys, and heart. The major complication of most forms of the disorder is pulmonary fibrosis, which typically exhibits in patients ages 40–50 years. This is a fatal complication seen in many forms of HPS, and is the usual cause of death from the disorder. HPS patients who develop pulmonary fibrosis typically have type 1 or type 4. Research
HPS is one of the rare lung diseases currently being studied by The Rare Lung Diseases Consortium (RLDC). The RLDC is part of the Rare Diseases Clinical Research Network (RDCRN), an initiative of the Office of Rare Diseases Research (ORDR), of the National Center for Advancing Translational Sciences (NCATS). The RLDC is dedicated to developing new diagnostics and therapeutics for patients with rare lung diseases, through collaboration between the NIH, patient organizations and clinical investigators. Eponym
It is named for František Heřmanský (1916–1980) and Pavel Pudlák (1927–1993). See also
Biogenesis of lysosome-related organelles complex 1
List of cutaneous conditions

References
External links
GeneReviews/NCBI/NIH/UW entry on Hermansky-Pudlak Syndrome