HPS is an autosomal recessive disorder characterized by
- Oculocutaneous albinism
- A bleeding diasthesis (absense of dense bodies)
- Sometimes pulmonary fibrosis
- Sometimes granulomatous colitis.
The renal failure, pulmonary fibrosis, and granulomatous colitis are associated with lysosomal accumulation of amorphous lipid-protein complexes called ceroid lipofuscin. This is seen on the limited number who have undergone renal biopsy. The ceroid deposits accumulate in renal tubular epithelial cells of the proximal tubules with sparing of the glomerular epithelial cells and the distal tubular epithelium. Pathogenesis is still speculative and treatment options other than supportive care are currently unavailable.