[2 patients with autosomal recessive generalized myotonia]

Two men aged 20 and 18 years complained of transient muscle stiffness of 4 and 2 years' duration, respectively. Symptoms had started in the legs. Gradually, arm muscles and eventually facial and pharyngeal muscles became affected. Neurological examination revealed myotonia without any associated symptoms. Myotonia was confirmed by electromyography. Laboratory investigations, ECG, chest X-rays, slit lamp examination in both patients, and muscle biopsy in one, revealed no abnormalities. History, physical examination and electromyography of family members disclosed no evidence of myotonic dystrophy. Based on the findings mentioned, the diagnosis of autosomal recessive generalised myotonia was made.