Muscle biopsy specimens from 30 muscular dystrophy patients were examined for a deficiency of adhalin, the 50-kd dystrophin-associated protein, at the University of Pittsburgh School of Medicine, PA. Of 3 patients with neonatal-onset congenital MD, 11 with childhood-onset MD, and 16 with early adult-onset MD (limb-girdle MD), only one, a 16-year-old African-American girl with childhood-onset MD, had adhalin gene mutations. All patients had autosomal recessive inheritance patterns, and all had serum CK levels higher than 1000 IU/liter. 
COMMENT. Primary adhalin deficiency in patients with muscular dystrophy with normal dystrophin is a relatively rare occurrence. It is not restricted to French families in which it was first reported. The phenotype is consistent with childhood-onset muscular dystrophy.
Approximately 60% of MD patients show absence or deficiency of dystrophin. Of the remaining 40% with normal dystrophin, most have the genetically heterogeneous severe childhood form of autosomal recessive MD, or limb-girdle dystrophy, and 1 in 30 may have a primary adhalin deficiency.