Mouse Genome Informatics
involves: 129P2/OlaHsd * C57BL/6
phenotype observed in females
phenotype observed in males
N normal phenotype

Peripheral neuropathology in Sbf2Gt(RRF511)Byg/Sbf2Gt(RRF511)Byg mice

nervous system
• myelin infolds and outfolds are seen on nerve fibers of the sciatic and saphenous nerves
• outfolds are seen on both small and large caliber fibers and consist of one or more satellite loops of myelin that sometimes contain axoplasm-like material
• infolds consist of myelin folded into the axon and may dramatically alter the profile of the axon
• infrequently fibers may contain both infolds and outfolds
• the percentage of fibers with infolds or outfolds increases with age as does the complexity of the folds
• folds are most prominent adjacent to nodes of Ranvier which alter the shape of the node but do not affect its overall organization
• however, myelin thickness is not decreased, degenerating axons are only rarely seen and onion bulb formations seen in human patients with CMT4B are not seen
• decreased motor nerve conduction velocity at 8 months of age

• some older mice display wide placement of the hind limbs when placed on a flat surface

Mouse Models of Human Disease
Charcot-Marie-Tooth Disease, Type 4b2; CMT4B2 604563 J:133391