Phenotypes associated with this allele

• Allele Symbol: Htt^tm7Mem
• Allele Name: targeted mutation 7, Marcy E MacDonald
• Allele ID: MGI:3697906
• Summary: 2 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Htt^tm7Mem/Htt^tm7Mem	involves: 129S/SvEv * 129S1/Sv * 129X1/SvJ * CD-1	MGI:3698001
ht2	Htt^tm1Mem/Htt^tm7Mem	involves: 129S/SvEv * 129S1/Sv * 129X1/SvJ * CD-1	MGI:3698007

Genotype
MGI:3698001

hm1

• Allelic Composition: Htt^tm7Mem/Htt^tm7Mem
• Genetic Background: involves: 129S/SvEv * 129S1/Sv * 129X1/SvJ * CD-1

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

mortality/aging

neonatal lethality, complete penetrance ( J:44391 )

• survivors die within 2 days after birth

perinatal lethality, incomplete penetrance ( J:44391 )

• almost one half are stillborn

nervous system

abnormal midbrain morphology ( J:44391 )

• enlarged furrowed midbrain that hides the cerebellum

abnormal cerebral aqueduct morphology ( J:44391 )

• the aqueduct is enlarged and displaced

enlarged cerebral aqueduct ( J:44391 )

abnormal forebrain morphology ( J:44391 )

• elongated and misshapen forebrain

abnormal thalamus morphology ( J:44391 )

• architectural abnormalities

abnormal telencephalon morphology ( J:44391 )

• architectural anomalies in the septal nucleus

abnormal lateral ventricle morphology ( J:44391 )

• lateral ventricles are displaced

• ectopic tissue masses are found in the lateral ventricles

dilated lateral ventricle ( J:44391 )

abnormal striatum morphology ( J:44391 )

• architectural abnormalities

• however, newborn brains do not exhibit evidence of the striatal or cortical pathology that is seen in Huntington's disease

abnormal cerebral cortex morphology ( J:44391 )

• architectural abnormalities in the parasagittal cerebral cortex

abnormal postnatal subventricular zone morphology ( J:44391 )

• newborns exhibit ectopic tissue masses in the subventricular zone

abnormal nervous system tract morphology ( J:44391 )

• agenesis of white-matter tracts

abnormal anterior commissure morphology ( J:44391 )

• anterior commissure is not well formed

craniofacial

abnormal cranium morphology ( J:44391 )

• oddly shaped, elongated cranium

lowered ear position ( J:44391 )

• uni- or bilateral

abnormal ear shape ( J:44391 )

• uni- or bilateral misshapen and narrowed external ears

hearing/vestibular/ear

lowered ear position ( J:44391 )

• uni- or bilateral

abnormal ear shape ( J:44391 )

• uni- or bilateral misshapen and narrowed external ears

skeleton

abnormal cranium morphology ( J:44391 )

• oddly shaped, elongated cranium

integument

thick skin ( J:44391 )

• thickened dehydrated skin

growth/size/body

lowered ear position ( J:44391 )

• uni- or bilateral

abnormal ear shape ( J:44391 )

• uni- or bilateral misshapen and narrowed external ears

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
NOT	Huntington's disease	DOID:12858	OMIM:143100	J:44391

Genotype
MGI:3698007

ht2

• Allelic Composition: Htt^tm1Mem/Htt^tm7Mem
• Genetic Background: involves: 129S/SvEv * 129S1/Sv * 129X1/SvJ * CD-1

mortality/aging

perinatal lethality, complete penetrance ( J:44391 )

• no mutants observed at weaning but some are present as stillborn pups

lethality throughout fetal growth and development, incomplete penetrance ( J:44391 )

• the expected numbers are seen at E18.5, however 7 of 18 are either dead or in the process of being absorbed, indicating that some die before E18.5

nervous system

abnormal cerebellum development ( J:44391 )

• cerebellum is misshapen and appears underdeveloped

abnormal brain ventricle morphology ( J:44391 )

• the tightly organized layer of neuroepithelium at the ventricular surface is absent or is replaced or obscured by Map2 immunoreactive postmitotic neuronal cells

abnormal midbrain morphology ( J:44391 )

• midbrain is distorted by the abnormally large aqueduct

abnormal cerebral aqueduct morphology ( J:44391 )

• aqueduct is abnormally dilated

abnormal forebrain morphology ( J:44391 )

• forebrain is misshapen

abnormal thalamus morphology ( J:44391 )

• thalamus is malformed and displaced

abnormal telencephalon morphology ( J:44391 )

• along the midline, the entire septal area is misshapen and reduced

dilated lateral ventricle ( J:44391 )

• lateral ventricles are abnormally dilated

abnormal striatum morphology ( J:44391 )

• exhibit abnormal organization and thickening of the striatal subventricular zone

• however, the striatum does not show evidence of Huntington's disease-like pathology

abnormal hippocampus morphology ( J:44391 )

• hippocampus is malformed and displaced

absent hippocampal fimbria ( J:44391 )

• agenesis of the fimbria

abnormal olfactory bulb morphology ( J:44391 )

• olfactory bulbs are malformed and displaced

abnormal embryonic/fetal subventricular zone morphology ( J:44391 )

• display abnormal organization and thickening of the striatal subventricular zone that contains ectopic cell masses that protrude into the lateral ventricles

exencephaly ( J:44391 )

• 4 of 11 fetuses exhibit exencephaly, with the forebrain and midbrain protruding from the open skull

abnormal nervous system tract morphology ( J:44391 )

• fiber tracts exhibit extensive agenesis

cardiovascular system

abnormal blood vessel morphology ( J:44391 )

• head region is conspicuously vascularized

craniofacial

domed cranium ( J:44391 )

• domed cranium

abnormal ear position ( J:44391 )

• uni- or bilateral misplaced external ears

abnormal ear shape ( J:44391 )

• uni- or bilateral misshapen external ears

hearing/vestibular/ear

abnormal ear position ( J:44391 )

• uni- or bilateral misplaced external ears

abnormal ear shape ( J:44391 )

• uni- or bilateral misshapen external ears

skeleton

domed cranium ( J:44391 )

• domed cranium

integument

thick skin ( J:44391 )

• thickened waxy skin

growth/size/body

abnormal head morphology ( J:44391 )

• pups alive at E18.5, display a more severe head phenotype than seen in Hdh^tm7Mem homozygotes

abnormal ear position ( J:44391 )

• uni- or bilateral misplaced external ears

abnormal ear shape ( J:44391 )

• uni- or bilateral misshapen external ears

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
NOT	Huntington's disease	DOID:12858	OMIM:143100	J:44391