HPS4 Hermansky-Pudlak syndrome type 4 is a rare genetic disorder that affects multiple body systems. It is characterized by albinism, vision problems, and a bleeding tendency due to platelet dysfunction. Individuals with HPS4 may have pale skin, light-colored hair, and vision problems such as reduced visual acuity and nystagmus (involuntary eye movements). They may also experience easy bruising and prolonged bleeding after injuries or surgeries.

HPS4 is caused by mutations in the HPS4 gene, which is involved in the formation and function of specialized cell structures called melanosomes and platelet dense granules. Melanosomes are responsible for the production and distribution of melanin, the pigment that gives color to the skin, hair, and eyes. Platelet dense granules contain substances necessary for normal platelet function, which is important for blood clotting.

Due to the defective function of melanosomes and platelet dense granules, individuals with HPS4 have reduced melanin production and abnormal platelet function. This results in the characteristic features of albinism and bleeding tendency seen in HPS4.

There is currently no cure for HPS4 Hermansky-Pudlak syndrome type 4. Treatment aims to manage the symptoms and complications associated with the disorder. This may include the use of visual aids, such as glasses or contact lenses, to improve vision, and measures to control bleeding, such as avoiding certain medications and taking precautions to prevent injuries.

Genetic counseling may be recommended for individuals with HPS4 and their families to understand the inheritance pattern and the risk of passing on the condition to future generations.