This is the first report that describes the clinical and histological findings in a patient suffering from pure congenital fibre type disproportion (CFTD), who had two biopsies with an interval of 16 years. Additionally, we compared the clinical signs and symptoms of the present case to those of 35 CFTD cases reviewed from the literature. From this we conclude that smallness of type I fibre diameter is not a characteristic feature during the course of pure CFTD. This suggests that CFTD is a time-locked diagnosis.