Phenotypes Associated with This Genotype

Genotype
MGI:3513600

• Allelic Composition: Mtmr2^tm1.1Abol/Mtmr2^tm1.1Abol
• Genetic Background: involves: 129S2/SvPas

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

mortality/aging

prenatal lethality, incomplete penetrance ( J:94373 )

• significant number of null mice are not born (14% versus the expected 25% born were null)

behavior/neurological

limb grasping ( J:94373 )

• occasionally clenched paws when suspended by the tail

tremors ( J:94373 )

• occasionally showed mild tremor

abnormal gait ( J:94373 )

• significantly wider base and longer stride at 6 months of age suggesting a neuromuscular abnormality

long stride length ( J:94373 )

growth/size/body

decreased body weight ( J:94373 )

• males weighed less than wild-type at all ages

limbs/digits/tail

abnormal autopod morphology ( J:94373 )

• occasionally had widely placed hindpaws

reproductive system

abnormal spermatogenesis ( J:94373 )

♂ • at 3 weeks of age, some seminiferous tubules showed premature germ cell loss from the epithelium and at 4 months of age, elongating/elongate spermatids and spermatocytes shed from the epithelium and entered the lumen of tubules in mutant testes

nervous system

abnormal sciatic nerve morphology ( J:94373 )

• myelin foldings and recurrent loops were seen in myelin-forming Schwann cells of the sciatic nerve

axon degeneration ( J:94373 )

• at 6 months of age, occasional degenerating axons were seen in sciatic nerve

abnormal myelination ( J:94373 )

• myelin outfolding (appeared as comma shaped extension of myelin and axoplasm), recurrent loops (appeared as one to five satellite myelinated axons around a larger myelinated axon), and myelin protruding into the axon were seen in sciatic nerves, quadriceps and saphenous nerves, predominantly at paranodal myelin

• number of fibers containing myelin outfoldings and loops increased progressively in sciatic nerves with age (from 1-6 months) as did the complexity of myelin outfoldings

abnormal nerve conduction ( J:94373 )

• reduced nerve conduction velocities (30.8 m/s vs. 38.7 m/s in wild-type) and prolonged F-wave latencies

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Charcot-Marie-Tooth disease type 4B1		DOID:0110191	OMIM:601382	J:94373