tokens: Among these , we registered 13.4/100,000 myotonic dystrophy type 1 , 6.8/100,000 myotonic dystrophy type 2 , 7.3/100,000 Duchenne muscular dystrophy , 1.6/100,000 Becker muscular dystrophy , 3.7/100,000 facioscapulohumeral muscular dystrophy , 12.8/100,000 limb - girdle muscular dystrophy , 2.5/100,000 hypokalemic periodic paralysis and 11.4/100,000 myotonia congenita .