Phenotypes Associated with This Genotype

Genotype
MGI:5779417

• Allelic Composition: Tg(Pmp22)My41Clh/0
• Genetic Background: involves: C57BL/6J * CBA/Ca

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

mortality/aging

premature death ( J:76795 )

• mice rarely survive 5 months

behavior/neurological

weakness ( J:76795 )

• weakness of hind limbs

abnormal gait ( J:76795 )

• unstable gait

• gait abnormalities become obvious by 3 weeks and progressively worsen

nervous system

abnormal submucous nerve plexus morphology ( J:76795 )

• Ramak fibers (bundles of unmyelinated axons surrounded by a single Schwann cell) show an excess of Schwann cell membrane formation

increased Schwann cell number ( J:76795 )

• number of Schwann cells is increased by about 3 times the normal number

decreased myelin sheath thickness ( J:76795 )

• where myelin sheaths are present, they exhibit increased g ratio indicating thinner myelin

axon degeneration ( J:76795 )

• axonal loss in both the proximal and the distal tibial nerves of 5-6 month old mice

• however, axonal loss at the mid sciatic level is not seen

abnormal myelination ( J:76795 )

• at P4, myelination is delayed in the sciatic nerve, with only 4.6% of axons myelinated compared to 54.2% in controls and only 255 of axons myelinated in adults

• lack of large myelinated fibers

• myelin periodicity is slightly but not significantly increased

demyelination ( J:76795 )

• mice exhibit a severe demyelinating peripheral neuropathy

• however, mice do not exhibit hypertrophic changes like increased fascicle size or classical onion bulbs

dysmyelination ( J:76795 )

• 73.7% of axons have either no myelin or myelin that is too thin to be measured

• dysmyelinated fibers are those that have either been demylinated or have completely failed to elaborate any myelin

• many dysmyelinated axons in the sciatic nerve are incompletely surrounded by Schwann cell cytoplasm and others do not have any visible Schwann cell contact

reproductive system

reduced female fertility ( J:76795 )

♀ • females have one, or at most two, litters when mated to wild-type males and then cease to reproduce

male infertility ( J:76795 )

♂ • males do not breed with wild-type females

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Charcot-Marie-Tooth disease type 1A		DOID:0110148	OMIM:118220	J:76795