Clinical, morphological and biochemical features in the familial articular hypermobility syndrome (FAHS): a family study.

A female with clinical features of familial articular hypermobility syndrome (FAHS) and her family were studied. The subject showed generalized hypermobility, except for a painful shoulder which presented functional limitation with a diagnosis of painful shoulder syndrome. Biochemical studies demonstrated that collagen and glycosaminoglycans (GAGs) contents from skin biopsies of the subject and her family were almost normal. Nevertheless, the densitometric analysis of electrophoretic patterns showed differences in the relative proportions of their collagenous components. They were characterized by changes in type I and III collagens and the presence of type V collagen, in the subject, her father and brother. Also, they presented changes in the types of GAGs, when compared with those of normal skin. Morphological studies revealed a general disorganization of dermal components, a loose collagen network characterized by thick bundles. Also, besides cellular elements, the presence of an abundant darkly staining material was observed. Biochemical and morphological findings permit us to suggest a connective tissue defect, initially described in the FAHS, otherwise known as Ehlers Danlos syndrome (EDS) type XI.