Mouse Genome Informatics
hm
    Hspg2tm1Soni/Hspg2tm1Soni
involves: 129S/SvEv * DBA/2J
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
nervous system
• shorter internodal lengths at 2 and 8 months of age with a concomitant increase in the number of myelinating Schwann cells
• the distribution of axonal diameters is slightly shifted toward higher values but the mean nerve fiber diameter is similar to controls resulting in an increased mean g ratio
• marked increase in the number of Schmidt-Lanterman incisures and adjacent juxtaincisures at 8 months of age
• increase is less pronounced at 2 months of age compared to 8 months of age
• shorter internodal lengths at 2 and 8 months of age with a concomitant increase in the number of myelinating Schwann cells
• polyaxonal myelination is more frequently seen compared to wild-type controls in sciatic nerves
• however, no evidence of demyelination or remyelination is detected in sciatic nerves
• increase in the mean length of the nodal gap on teased sciatic nerve fibers and in longitudinal nerve sections at 8 months of age
• mild increase in length
• major remodeling is seen in tibialis anterior longitudinal sections with incomplete apposition of presynaptic and postsynaptic components, thin terminal nerves and short sprouting of terminal Schwann cells suggestive of reinnervation processes
• dysmyelination of preterminal segments in neuromuscular junctions with age
• however, no evidence of demyelination or remyelination is detected in sciatic nerves
• display bursts of motor unit action potential firing at high rates (120 to 300 Hz; neuromyotonic discharges) at 8 months of age
• peripheral nerve hyperexcitability is seen in the paraspinal and facial muscles at 2 months of age and becomes more severe with age
• greater attenuations of compound nerve action potentials are detected in vitro assays suggest that persistent axonal depolarization may occur in nerves

Mouse Models of Human Disease
OMIM IDRef(s)
Schwartz-Jampel Syndrome, Type 1; SJS1 255800 J:183547