We recently reported the selective reduction of the B1 subunit of laminin in two Japanese patients with adhalin deficiency. We here investigated immunohistochemically the expression of other components of the extracellular matrix (ECM), including collagen type IV, heparan sulfate proteoglycan can (HSPG), chondroitin-4-sulfate proteoglycan, decorin, and fibronectin in adhalin deficiency, compared with other types of muscular dystrophy. We found a reduction of HSPG on the basal lamina surrounding each muscle fiber in adhalin deficiency compared with HSPG in other diseases. This finding may be characteristic evidence of the disturbance of the sarcolemma-ECM interaction and the sarcolemmal instability in adhalin deficiency. Recently, a direct role of HSPG in fibroblast growth factor (FGF) signal transduction was demonstrated. Further investigation is required to determine if the dysfunction of FGF is relevant to the pathogenesis of adhalin deficiency.