Hermansky-Pudlak syndrome

Hermansky-Pudlak syndrome is a rare autosomal recessive inherited disease characterized by oculocutaneous albinism, reduced platelet function, pulmonary fibrosis and granulomatous colitis; renal failure is less common, but possible.
This pathology is caused by mutations of genes coding for proteins involved in the formation / function of lysosome-related cell organelles (LORs), present in certain cell types such as melanocytes, pigmented epithelial cells, platelets and some classes of lymphocytes. LORs are similar to lysosomes, organelles specializing in the digestion of cellular debris and foreign particles.
Therefore, the specific phenotypes linked to this condition derive from the altered cell type: the predisposition to bleeding is due to the lack of dense granules, which prevents platelets from aggregating; albinism, characterized by very light skin, hair and eyes (a condition that predisposes to a greater risk of skin cancer) is linked to defects in melanosomes, while pulmonary fibrosis and colitis are due to the accumulation of ceroid lipofuscin (molecules non-degradable resulting from the demolition of lipids and proteins).
The Hermansky-Pudlak Syndrome is divided into 9 types, which differ in the severity of the symptoms and the underlying mutations: types 1 and 4 are the most severe and, together with type 2, are those presenting pulmonary fibrosis; subjects affected by types 3, 5 and 6 have milder symptoms, while types 7, 8 and 9 are the least known.
The most frequent mutation in Hermansky-Pudlak Syndrome involves the HPS1 gene, followed by HPS3