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.<unk>  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<unk> . 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.
Hermansky–Pudlak syndrome
Keppen–Lubinsky syndrome
Sakati–Nyhan–Tisdale syndrome
Fox–Fordyce disease
Conradi–Hünermann syndrome
Kandinsky–Clérambault syndrome
Hallermann–Streiff syndrome
Shprintzen–Goldberg syndrome