The disaccharide content of the chondroitinase-digestible glycosaminoglycans (GAGs) extracted from 6-mm skin punch biopsies from the atrophic and sclerotic skin of two patients with Werner's syndrome (WS) were determined using high-performance liquid chromatography after 1-phenyl-3-methyl-5-pyrazolone labelling. The total amount of main disaccharides was significantly decreased in the atrophic lesions of WS. In the atrophic forearm skin, the decrease in the main disaccharide unit of hyaluronic acid, delta Di-HA, and the increase in the ratio of the main disaccharide unit of dermatan sulphate, delta Di-4S, to delta Di-HA were significant vs. normal control (P < 0.01 and 0.05, respectively). The sclerotic skin showed an increase in delta Di-4S (DS) (P < 0.05) and a decrease in delta Di-HA (P < 0.02) compared with normal controls, as well as a significantly higher ratio of delta Di-4S (DS)/delta Di-HA compared with normal controls (P < 0.0002) and systemic sclerosis patients (SSc; P < 0.02). No other statistical difference was found in the amount of each main disaccharide unit between the sclerotic skin of WS and SSc. Histological examination revealed that the atrophic skin showed thinning of the dermis with a slight increase of fine collagen bundles, whereas the sclerotic skin demonstrated a thickened dermis with prominent deposition of fine collagen bundles in the deep dermis. In SSc, thickening of the whole dermis, composed of hyalinized or swollen collagen bundles, was found.(ABSTRACT TRUNCATED AT 250 WORDS)