myotonic muscular dystrophy

Does myotonic muscular dystrophy ever present with persistant muscle twitches? I first started noticing symptoms of muscle weakness in my legs and feet about 7 years ago, which are now also in my face and arms/hands. The muscle weakness is accompanied by the twitches. I've been tested for almost every neurological disorder, including ALS, and all the tests have been clear/negative. I found an article on MMD and recognized some of my symptoms.Another question I have is, I am the youngest of 7 children...all of my siblings are perfectly healthy and normal, no muscle weakness or anything. I'm 32 and my next oldest sibling is 40, followed by siblings of ascending age up to their mid 50s. If I had MMD with 6 brothers and sisters, wouldn't any of them have it as well?
Also, is MMD ever accompanied by hyper reflexes in the knees, wrists, etc, or is it the opposite? I've read a couple conflicting articles on it; one that said you develop "increased" reflexes, and one that said you have "decreased reflexes."
Thanks for any info, Bobby.