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Hermansky-Pudlak syndrome in a Swiss population
K U Schallreuter1, E Frenk, L S Wolfe
1Department of Dermatology, University of Hamburg, FRG.
Dermatology (Basel, Switzerland)
|January 1, 1993
Summary
Swiss and Puerto Rican Hermansky-Pudlak Syndrome (HPS) patients exhibit similar platelet defects and thioredoxin reductase (TR) activity. However, Swiss HPS cases lack the severe systemic storage disease seen in Puerto Rican patients.
Area of Science:
- Human Genetics
- Biochemistry
- Dermatology
Background:
- Tyrosinase-positive albinism, previously diagnosed as Hermansky-Pudlak Syndrome (HPS), presents a spectrum of clinical manifestations.
- Understanding the biochemical and genetic underpinnings of HPS is crucial for diagnosing and managing affected individuals.
- Previous studies have identified similarities and differences in HPS presentations across diverse populations.
Purpose of the Study:
- To investigate the biochemical and clinical characteristics of HPS in a Swiss family across four generations.
- To compare the Swiss HPS phenotype with that of HPS patients from Puerto Rico.
- To examine the role of antioxidant enzymes, specifically thioredoxin reductase (TR), in HPS pathogenesis.
Main Methods:
- Analysis of membrane-associated thioredoxin reductase (TR) activities in family members and controls.
- Assessment of bleeding times and platelet dense body content.
- Examination of antioxidant enzymes (catalase, TR, glutathione reductase) in epidermal suction blisters.
- Histological analysis for ceroid/lipofuscin-like pigment and urinary dolichol excretion.
Main Results:
- Swiss HPS homozygotes and heterozygotes showed reduced membrane-associated TR activity and platelet dense body deficiency, similar to Puerto Rican HPS.
- Unlike Puerto Rican HPS, Swiss HPS cases exhibited normal life expectancy, no significant ceroid accumulation, and no increased urinary dolichol excretion.
- Swiss HPS homozygotes displayed altered intracellular TR (calcium-free) and elevated glutathione reductase in epidermal cells compared to controls and vitiligo patients.
- Giant melanosomes were observed in skin melanocytes of both Swiss and Puerto Rican HPS individuals.
Conclusions:
- The Swiss HPS genetic lineage shares key biochemical and platelet abnormalities with Puerto Rican HPS but lacks severe systemic storage disease.
- This suggests distinct genetic modifiers or environmental factors influencing the clinical spectrum of HPS.
- Altered antioxidant enzyme profiles, particularly TR, may play a role in HPS pathophysiology, warranting further investigation.
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