Changes of laminin β2 chain expression in congenital muscular dystrophy

We studied the distribution of laminin β2 chain in the skeletal muscle basement membrane of 16 patients with congenital muscular dystrophy (CMD) by immunohistochemistry. A dramatic reduction in the laminin β2 staining was observed in four patients with classical merosin-negative CMD. A moderate reduction of laminin β2 labelling was observed in four patients with partial merosin deficiency and two patients with merosin-positive CMD. Two patients with merosin-positive CMD had no apparent changes in the expression of laminin β2. In three patients and one fetus diagnosed as Walker-Warburg syndrome (WWS) the laminin β2 pattern was similar to normal controls. We conclude that a primary deficiency in the laminin α2 chain may lead to a vast or moderate reduction in the laminin β2 chain in the skeletal muscle membrane.