Dystrophin deficiency in a case of congenital myopathy.

We studied a 5-year-old boy who had the "floppy infant syndrome" and a dystrophic pattern on muscle biopsy. According to the clinical presentation and the histopathological findings the diagnosis of congenital muscular dystrophy with associated intellectual retardation was made. Immunohistochemical and immunoblot studies using anti-dystrophin antibodies showed complete absence of the protein in the patient's muscle. DNA analysis using cDNA probes showed a deletion at the 5' end of the dystrophin gene. Our observations on this patient suggest a new phenotypical variant of Duchenne muscular dystrophy.