Needle biopsies of muscle in infants for diagnosis and research.

The results of needle biopsies of muscle in 14 infants (age-range four months to 3 years 3 months) with marked hypotonia are presented. In adults, needle biopsies of muscle have been used to aid in the diagnosis of neuromuscular disorders, with considerable success. The simplicity of the method and the high quality of the samples obtained in the present study suggest that further evaluation of the technique in infants and small children is warranted, and that needle biopsy may in future take precedence over the more commonly used open technique.