TWO REPORTS appeared almost simultaneously, in 1963, describing a new myopathy. The condition was characterized pathologically by nuṃerous inclusions in muscle fibers referred to variously as myogranules, nemaline (thread-like) structures, or rod-like bodies.1,2
These initial cases together with other subsequent reports3-8 were considered to represent a disease entity with identical pathological findings and many of the following clinical features: "floppy infant"; delayed motor development; proximal limb weakness, usually with hypotonia; reduced muscle bulk; reflexes usually absent; onset from birth, most noticeable on initial attempt to walk; associated deformities, particularly pes cavus, high-arched palate, kyphosis or scoliosis; possibly (autosomal) dominant inheritance; and extremely slow or nonprogressive course.
Since this disorder was first brought to light, Engel and Resnick9 and Engel10 described a disorder in which there were rodlike structures but this disorder was of late onset, noninherited, and progressive. The question has therefore been raised whether
Heffernan LP, Rewcastle NB, Humphrey JG. The Spectrum of Rod Myopathies. Arch Neurol. 1968;18(5):529–542. doi:10.1001/archneur.1968.00470350087008