Myopathy NEB (p.R2478_D2512del) is characterized by weakness (usually most severe in the face, neck flexors, and proximal limb muscles), hypotonia, and the presence of nemaline bodies or rods in affected muscle fibers.

The disease is clinically heterogeneous and can be further classified into 6 forms based upon onset and severity of motor and respiratory involvement: severe congenital (neonatal) form; Amish NM, intermediate congenital form; typical congenital form; childhood-onset form; and adult-onset (late-onset) form. Nemaline myopathy is typically inherited in an autosomal recessive manner, but can also be passed on as an autosomal dominant or arise from a de novo mutation.