Phenotypes Associated with This Genotype

Genotype
MGI:6281675

• Allelic Composition: Chd7^Looper/Chd7⁺
• Genetic Background: BALB/c-Chd7^Looper

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

behavior/neurological

abnormal motor capabilities/coordination/movement ( J:252089 )

• mice exhibit a longer latency to fall from a rotating rod

• however, they show normal digigait test results, indicating that directional control, but not motor coordination, is impaired

decreased startle reflex ( J:252089 )

• mice startle less than wild-type littermates in response to mixed frequency noise

increased locomotor activity ( J:252089 )

• mice spend more time moving than controls during locomotor cell testing, indicating hyperactivity

• on average, mice run twice as quickly and travel twice as far as controls

circling ( J:252089 )

• mice exhibit circling behavior

• mice are inclined to circle within the center of the test arena compared to controls that prefer the edges

• during the swim test, mice swim in circles compared to controls that occasionally float motionless or seek refuge at the outskirts of the test arena

craniofacial

otosclerosis ( J:252089 )

• stapes shows an ectopic bone bridge extending from the tubercle to the otic capsule

abnormal oval window morphology ( J:252089 )

• fusion of the stapedial footplate to the oval window of the cochlea

abnormal middle ear ossicle morphology ( J:252089 )

• ossicles show a range of malformations

• however, mid-modiolar cochlea sections are normal

abnormal incus morphology ( J:252089 )

• the incus shows malformation of the facet

abnormal incus long process morphology ( J:252089 )

• the incus shows incomplete development of the long process

abnormal incus short process morphology ( J:252089 )

• the incus shows incomplete development of the short process

abnormal malleus manubrium morphology ( J:252089 )

• the malleus manubrium protrudes at an abnormally acute angle while the neck is thickened and malformed

abnormal stapes morphology ( J:252089 )

• stapes is rounded and small with an ectopic bone bridge extending from the tubercle to the otic capsule

abnormal stapes footplate morphology ( J:252089 )

• fusion of the stapedial footplate to the oval window of the cochlea

facial asymmetry ( J:252089 )

eyelid edema ( J:252089 )

growth/size/body

facial asymmetry ( J:252089 )

eyelid edema ( J:252089 )

decreased body weight ( J:252089 )

• mice are 30% lighter than controls

postnatal growth retardation ( J:252089 )

hearing/vestibular/ear

otosclerosis ( J:252089 )

• stapes shows an ectopic bone bridge extending from the tubercle to the otic capsule

abnormal oval window morphology ( J:252089 )

• fusion of the stapedial footplate to the oval window of the cochlea

abnormal middle ear ossicle morphology ( J:252089 )

• ossicles show a range of malformations

• however, mid-modiolar cochlea sections are normal

abnormal incus morphology ( J:252089 )

• the incus shows malformation of the facet

abnormal incus long process morphology ( J:252089 )

• the incus shows incomplete development of the long process

abnormal incus short process morphology ( J:252089 )

• the incus shows incomplete development of the short process

abnormal malleus manubrium morphology ( J:252089 )

• the malleus manubrium protrudes at an abnormally acute angle while the neck is thickened and malformed

abnormal stapes morphology ( J:252089 )

• stapes is rounded and small with an ectopic bone bridge extending from the tubercle to the otic capsule

abnormal stapes footplate morphology ( J:252089 )

• fusion of the stapedial footplate to the oval window of the cochlea

abnormal lateral semicircular canal morphology ( J:252089 )

• incomplete development of the lateral semicircular canal

abnormal posterior semicircular canal morphology ( J:252089 )

• various degrees of hypoplasia of the posterior canal

abnormal superior semicircular canal morphology ( J:252089 )

• various degrees of hypoplasia of the anterior canal

increased or absent threshold for auditory brainstem response ( J:252089 )

• auditory brainstem response (ABR) thresholds are elevated between 4 and 32 kHz

• Background Sensitivity: the average click ABR threshold is higher on the BALB/c background than on a mixed C57BL/6 and BALB/c background

impaired hearing ( J:252089 )

• mice exhibit hearing loss

homeostasis/metabolism

eyelid edema ( J:252089 )

immune system

blepharitis ( J:252089 )

• 11 of 16 mice show eye irritation and blepharoconjunctivitis

conjunctivitis ( J:252089 )

• 11 of 16 mice show eye irritation and blepharoconjunctivitis

skeleton

otosclerosis ( J:252089 )

• stapes shows an ectopic bone bridge extending from the tubercle to the otic capsule

abnormal oval window morphology ( J:252089 )

• fusion of the stapedial footplate to the oval window of the cochlea

abnormal middle ear ossicle morphology ( J:252089 )

• ossicles show a range of malformations

• however, mid-modiolar cochlea sections are normal

abnormal incus morphology ( J:252089 )

• the incus shows malformation of the facet

abnormal incus long process morphology ( J:252089 )

• the incus shows incomplete development of the long process

abnormal incus short process morphology ( J:252089 )

• the incus shows incomplete development of the short process

abnormal malleus manubrium morphology ( J:252089 )

• the malleus manubrium protrudes at an abnormally acute angle while the neck is thickened and malformed

abnormal stapes morphology ( J:252089 )

• stapes is rounded and small with an ectopic bone bridge extending from the tubercle to the otic capsule

abnormal stapes footplate morphology ( J:252089 )

• fusion of the stapedial footplate to the oval window of the cochlea

abnormal glenoid fossa morphology ( J:252089 )

• incus shows deformed glenoid cavity

vision/eye

eyelid edema ( J:252089 )

blepharitis ( J:252089 )

• 11 of 16 mice show eye irritation and blepharoconjunctivitis

conjunctivitis ( J:252089 )

• 11 of 16 mice show eye irritation and blepharoconjunctivitis

narrow eye opening ( J:252089 )

• mice exhibit variable, narrowed palpebral fissures and lid edema, often with one eye severely affected and one moderately affected or normal eye

• however, coloboma is not seen

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
CHARGE syndrome		DOID:0050834	OMIM:214800	J:252089