Hermansky Pudlak syndrome 2

Alternate Names

HPS2; Hermansky-Pudlak syndrome 2; Platelet defects and oculocutaneous albinism

Definition

Hermansky-Pudlak syndrome type 2 (HPS-2) is a type of Hermansky-Pudlak syndrome , a multi-system disorder characterized by oculocutaneous albinism, bleeding diathesis and neutropenia.

Epidemiology

To date HPS-2 has been described in eight patients.

Clinical description

HPS-2 presents with features of HPS including oculocutaneous albinisim, reduced visual acuity, horizontal nystagmus, easy bruising of soft tissues, epistaxis, and prolonged bleeding after dental extraction, surgery or childbirth. Women may present with medically significant menstrual bleeding. In addition, HPS-2 patients present with recurrent infections due to neutropenia and impaired cytotoxic activity. Recently, pulmonary fibrosis has been described in some HPS-2 cases.

Cause

Autosomal recessive inheritance, a 25% chance

HPS-2 is caused by mutations in the AP3B1 gene (5q14.1) and is transmitted in an autosomal recessive manner. The gene product is the Beta 3A subunit of adaptor protein 3 (AP3), involved in vesicle formation and protein sorting.

Management and treatment

The neutropenia is responsive to granulocyte-cell stimulating factor (G-CSF).

NIH genetic and rare disease info

• NIH info on Hermansky Pudlak syndrome 2

Hermansky Pudlak syndrome 2 is a rare disease.