This report includes information relevant to a potential model of Hermansky-Pudlak syndrome 4 (HPS4), which is a subtype of Hermansky-Pudlak syndrome. The human gene implicated in this disease is HPS4, which encodes a protein component of biogenesis of lysosome-related organelles complexes (BLOC). There is one fly ortholog, HPS4, for which RNAi targeting constructs, alleles caused by insertional mutagenesis, and classical alleles have been generated.
For multiple subtypes of Hermansky-Pudlak syndrome, the implicated gene encodes a subunit of a BLOC complex, in this case the BLOC3 complex.
Human HPS4 has not yet been introduced into flies.
[updated Jul. 2017 by FlyBase; FBrf0222196]
Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder in which oculocutaneous albinism, bleeding, and lysosomal ceroid storage result from defects of multiple cytoplasmic organelles: melanosomes, platelet-dense granules, and lysosomes (Oh et al., 1998, pubmed:9497254). [from MIM:115200, 2016.03.25]
Hermansky-Pudlak syndrome (HPS) is a multisystem disorder characterized by: tyrosinase-positive oculocutaneous albinism; a bleeding diathesis resulting from a platelet storage pool deficiency; and, in some cases, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. The albinism is characterized by: hypopigmentation of the skin and hair; and ocular findings of reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in easy bruising, frequent epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects are associated primarily with HPS-2. [from GeneReviews, Hermansky-Pudlak Syndrome, pubmed:20301486 2016.01.26]
[HERMANSKY-PUDLAK SYNDROME 4; HPS4](https://omim.org/entry/614073)
[HPS4 BIOGENESIS OF LYSOSOMAL ORGANELLES COMPLEX 3, SUBUNIT 2; HPS4](https://omim.org/entry/606682)
Hermansky-Pudlak syndrome patients with a mutation in the HP4 gene have phenotypes including ocular findings of reduced iris pigment with iris transillumination, variable hair and skin pigmentation, absent platelet dense bodies, and occasional pulmonary fibrosis and granulomatous colitis. (Anderson, et al., 2003, pubmed:12664304). [From MIM:606682, 2016.03.24]
Hermansky-Pudlak syndrome 4 (HPS4) is caused by homozygous or compound heterozygous mutation in the HPS4 gene. [From MIM:614073, 2016.03.24]
HPS4 encodes a protein component of biogenesis of lysosome-related organelles complexes (BLOC). BLOC complexes are important for the formation of endosomal-lysosomal organelles such as melanosomes and platelet dense granules. [provided by RefSeq, Aug 2012]
One to one: 1 human to 1 Drosophila.