Phenotypes Associated with This Genotype

Genotype
MGI:5428882

• Allelic Composition: Hspg2^tm1Soni/Hspg2^tm1Soni
• Genetic Background: involves: 129S/SvEv * DBA/2J

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

nervous system

increased Schwann cell number ( J:183547 )

• shorter internodal lengths at 2 and 8 months of age with a concomitant increase in the number of myelinating Schwann cells

abnormal axon morphology ( J:183547 )

• 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

abnormal internode morphology ( J:183547 )

• 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

abnormal myelin sheath morphology ( J:183547 )

• 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

abnormal node of Ranvier morphology ( J:183547 )

• increase in the mean length of the nodal gap on teased sciatic nerve fibers and in longitudinal nerve sections at 8 months of age

abnormal paranode morphology ( J:183547 )

• mild increase in length

abnormal neuromuscular synapse morphology ( J:183547 )

• 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

demyelination ( J:183547 )

• dysmyelination of preterminal segments in neuromuscular junctions with age

• however, no evidence of demyelination or remyelination is detected in sciatic nerves

abnormal action potential ( J:183547 )

• 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		DO ID	OMIM ID(s)	Ref(s)
Schwartz-Jampel syndrome 1		DOID:0090005	OMIM:255800	J:183547