Is congenital fibre type disproportion a true myopathy?

The authors report a case of congenital fibre type disproportion in a 32-month-old male patient. A pathogenetic role of alcohol ("fetal alcohol syndrome") could be discussed here because the mother drank daily large quantities of alcohol during pregnancy. Histochemical features undistinguishable from those reported in congenital fibre type disproportion were also observed in two cases of globoid cell leucodystrophy (Krabbe's disease) and in one case of infantile acid maltase deficiency (Pompe's disease). Morphometric studies confirmed this analogy. The occurrence of a similar fibre type disproportion in conditions so completely different from each other casts doubts as to the specificity of these histoenzymatic features. It is suggested that at least some cases of congenital fibre type disproportion could result from a maturational insufficiency of type I motor neurons or from a damage brought to the Schwann cells.