Systemic hyalinosis or fibromatosis hyalinica multiplex juvenilis as a congenital syndrome. A new entity based on the inborn error of the acid mucopolysaccharide metabolism in connective tissue cells?

Abstract

Histochemical, biochemical and electronmicroscopic studies were carried out on a patient with a congenital connective tissue disorder consisting of joint contractures, cortical bone defects, gingival hypertrophy and skin and subcutaneous tumors. By cellulose acetate electrophoresis as well as by enzymatic digestion with chondroitinases, increased chondroitin 6 sulfate in the skin lesion of this patient was demonstrated. Moreover, electronmicroscopic study suggests its abnormal synthesis by the connective tissue cells. Chondroitin 6 sulfate is normally minimal in adult skin, but a primary constituent of bone and cartilage, and since it represents 20% of the acid glycosaminoglycans of embryonic pig skin, it may be assumed that in this syndrome the dermal connective tissue cells either failed to differentiate into those of normal postnatal skin or were transformed into those of bone or cartilage. Urinary acid glycosaminoglycans values were not elevated, which is in sharp contrast with the situation in mucopolysaccharidosis.