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General Information
Hermansky-Pudlak syndrome 9
FlyBase ID
Disease Ontology Term
Parent Disease

This report describes a model of Hermansky-Pudlak syndrome 9 (HPS9), which is a subtype of Hermansky-Pudlak syndrome; HPS9 exhibits autosomal recessive inheritance. The human gene implicated in this disease is BLOC1S6, which encodes biogenesis of lysosome-related organelles complex 1, subunit 6 (or pallidin), a subunit of the biogenesis of lysosome-related organelles complex 1 (BLOC1) that plays a role in organelle biogenesis associated with melanosomes, platelet dense granules, and lysosomes. There is one high-scoring fly ortholog, Pldn, for which RNAi targeting constructs 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 BLOC1 complex.

The human BLOC1S6 gene has not been introduced into flies.

Amorphic mutations of Dmel\Pldn have been generated; neuroanatomy and neurophysiology phenotypes are observed. The rapidly recycling vesicle pool is not sustained during high synaptic activity in Pldn mutants, leading to accelerated rundown and slowed recovery; following intense activity, loss of early endosomes is observed.

[updated Jul. 2019 by FlyBase; FBrf0222196]

Disease Summary Information
Parent Disease Summary: Hermansky-Pudlak syndrome
Symptoms and phenotype

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 OMIM: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]

Specific Disease Summary: Hermansky-Pudlak syndrome 9
OMIM report


Human gene(s) implicated


Symptoms and phenotype

See description of Hermansky-Pudlak syndrome, above.


Hermansky-Pudlak syndrome 9 (HPS9) is caused by homozygous mutation in BLOC1S6, the gene encoding biogenesis of lysosome-related organelles complex 1, subunit 6 (or pallidin), a component of the BLOC1 complex. [From OMIM:614171, 2016.04.11]

Cellular phenotype and pathology
Molecular information

BLOC1S6 encodes a protein that may play a role in intracellular vesicle trafficking. It interacts with Syntaxin 13 which mediates intracellular membrane fusion. [provided by RefSeq, Aug 2015]

External links
Disease synonyms
Hermansky-Pudlak syndrome 9; HPS9
Ortholog Information
Human gene(s) in FlyBase
    Human gene (HGNC)
    D. melanogaster ortholog (based on DIOPT)
    Comments on ortholog(s)

    One to one: 1 human to 1 Drosophila.

    Other mammalian ortholog(s) used
      D. melanogaster Gene Information (1)
      Gene Snapshot
      Pallidin (Pldn) encodes a core component of the biogenesis of lysosome-related organelles (BLOC-1) complex. It is involved in pigment granule biogenesis and synaptic vesicle recycling at the neuromuscular junction. [Date last reviewed: 2018-10-25]
      Molecular function (GO)
      Gene Groups / Pathways
      Comments on ortholog(s)

      Ortholog of human BLOC1S6 (1 Drosophila to 1 human).

      Dmel\Pallidin shares 31% identity and 52% similarity with human BLOC1S6.

      Orthologs and Alignments from DRSC
      DIOPT - DRSC Integrative Ortholog Prediction Tool - Click the link below to search for orthologs in Humans
      Synthetic Gene(s) Used (0)
      Summary of Physical Interactions (3 groups)
      Interacting group
      anti tag coimmunoprecipitation, peptide massfingerprinting, anti bait coimmunoprecipitation, anti tag western blot, western blot, two hybrid
      Alleles Reported to Model Human Disease (Disease Ontology) (0 alleles)
      Genetic Tools, Stocks and Reagents
      Sources of Stocks
      Contact lab of origin for a reagent not available from a public stock center.
      Bloomington Stock Center Disease Page
      Selected mammalian transgenes
      Publicly Available Stocks
      Selected Drosophila transgenes
      Publicly Available Stocks
      RNAi constructs available
      Publicly Available Stocks
      Selected Drosophila classical alleles
      Allele class
      Publicly Available Stocks
      amorphic allele - molecular evidence
      References (5)