Abstract
β‐Dystroglycan, a 43‐kd transmembrane dystrophinassociated glycoprotein, plays an important role in linking dystrophin to the laminin‐binding α‐dystroglycan. α‐/β‐Dystroglycan is encoded by a single gene on chromosome 3p21 and ubiquitously expressed in muscle and nonmuscle tissues. No known human diseases have been mapped to this locus. Here, we describe the selective deficiency of β‐dystroglycan in a 4‐year‐old Saudi boy with muscular dystrophy. The patient had a borderline elevation of serum creatine kinase level and early‐onset proximal symmetrical muscle weakness and wasting without calf hypertrophy. The milder phenotype may suggest a secondary deficiency of β‐dystroglycan; however, the unique immunofluorescence labeling suggests that the patient may present a novel form of muscular dystrophy.