Chemical analysis of an angiofibroma from a patient with tuberous sclerosis.

Amino-acid analyses on the acid hydrolysates of an angiofibroma and skin established that the former tissue contained less collagen than skin based on the reduced content of hydroxyproline, glycine, proline and alanine in the tumour. From lysosomal enzyme measurements it became evident that the specific activities of the hexosaminidases, beta-glucuronidase and beta-galactosidase were elevated. Analyses of the alcohol insoluble fraction following pronase digestion revealed that the tumour contained more acidic glycosaminoglycan (AG) than skin as assessed by uronic acid and hexosamine measurements. More outstanding, however, was the seven-fold increase in the total carbohydrate in the AG fraction of the tumour. The overall composition of this fraction was very similar to comparable material from foetal skin except that the tumour fraction contained increased sulphate concentration.