Phenotypes Associated with This Genotype

Genotype
MGI:3576120

• Allelic Composition: Egr2^tm1Jmi/Egr2^tm1Jmi
• Genetic Background: Not Specified

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

Runted phenotype and hindbrain defect of Egr2^tm1Jmi/Egr2^tm1Jmi mice

mortality/aging

postnatal lethality, complete penetrance ( J:96641 )

• 40% die within the first week of life, the remaining homozygotes survive into the third week of life

behavior/neurological

tremors ( J:96641 )

• severe tremors are seen

impaired coordination ( J:96641 )

growth/size/body

decreased body size ( J:96641 )

nervous system

increased Schwann cell proliferation ( J:96641 )

• increased numbers of proliferating Schwann cells are seen at P14

abnormal hindbrain development ( J:96641 )

• at E10.5, in 14% of mutants both rhombomeres 3 and 5 are absent, in 57% fusion of cranial nerves V, VII, and VIII is seen, and in 29% fusion of cranial nerves IX and X is seen

abnormal Schwann cell morphology ( J:96641 , J:99824 )

• an abundance of undifferentiated Schwann cells are seen associated with individual axons of the sciatic nerve (J:96641)

• at postnatal day 14 increased proliferation of Schwann cells is seen with 11.3 +/- 1.9% of the nuclei BrdU+ compared to less than 0.9% in wild-type mice (J:99824)

abnormal sciatic nerve morphology ( J:96641 )

• at P14 the sciatic nerve is thin and translucent

• the number of large and medium claiber axons is normal but, most lack myelin

abnormal myelination ( J:96641 , J:99824 )

• myelination is absent; however, no signs of demyelination are seen (J:96641)

cellular

increased Schwann cell proliferation ( J:96641 )

• increased numbers of proliferating Schwann cells are seen at P14

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
Charcot-Marie-Tooth disease type 4E		DOID:0110195	OMIM:605253	J:96641