Figure 4.

EM of muscle samples from patients 1 (severe congenital NM [a and b]) and 6 (childhood onset NM [c and d]). Nemaline bodies are present in all patients and are associated with disruption of the sarcomeric register. Rods appear either as extensions of sarcomeric Z-lines, in random array without obvious attachment to Z-lines (often in areas devoid of sarcomeres) or in large clusters localized at the sarcolemma or intermyofibrillar spaces (d). Glycogen accumulation (long arrow in panel a) and an increase in intermyofibrillar spaces (arrow in panel d) are common. Additional features include intranuclear rods (short arrow in panel a) and dramatically atrophied fibers (arrow in panel b) in patient 1, as well as whorling of thin filaments in patient 6 (arrow in panel c).