THE history of amyotonia congenita exemplifies impressively how diagnostic inaccuracy hinders scientific progress. Lack of appropriate laboratory tests, clinical follow-ups, and pathological documentation confused the semantics of neonatal and infantile hypotonia for decades. Although postmortem examinations showed that congenital hypotonia was due to degeneration of anterior horn cells in some cases and to primary disease of the muscle fiber in others, proper diagnosis became possible only after biochemical tests, electromyography, and muscle biopsy were utilized. Using these diagnostic tools, it became apparent that amyotonia congenita is a syndrome produced by a host of pathological conditions, some of which are primary muscle diseases.
Batten,1 as long ago as 1903, suspected on purely clinical grounds that a congenital primary muscular condition was responsible for amyotonia congenita. Although the nature of the disease in his cases was never confirmed by histological examinations, he is credited with the concept of congenital myopathy. Subsequent