As stated above, the most common genetic form of NM is caused by a mutation in the nebulin gene, called Nebulin, and has a range of severity levels. All published cases up to this point where NM is thought to be caused by a mutation in the "NEB" gene have been autosomal recessive and are the most common cause of nemaline myopathy. Patients with this kind of NM are more affected in the muscles in their head, rather than their proximal muscles at the core of their body. Consequently, patients with this genetic mutation often cannot lift their heads and speak with a nasal voice. There have been cases that suggest this kind of NM may lead to patients having higher intellect.