Clinicians in Hong Kong report an unusual case of congenital myasthenic syndrome (CMS) that initially suggested an eating disorder:
- the patient was 42 years old at the time of diagnosis with CMS (slow-channel type),
- the clinical picture included very significant progressive weight loss (down to 34 kg with a body mass index of 13.8) and had been attributed to anorexia nervosa for over ten years,
- yet there was no voluntary fasting, no desired weight loss, nor amenorrhoea to support this diagnosis,
- the findings from the clinical history (fatigue dating back to the age of ten) combined with those from the EMG (presence of a repetitive CMAP response) and genetic testing (positive family history, pathogenic variant in the CHRNA1 gene) enabled the diagnosis to be corrected and appropriate treatment with fluoxetine to be initiated.
