Phenotypes Associated with This Genotype

Genotype
MGI:6188328

• Allelic Composition: Abca12^smsk/Abca12^smsk
• Genetic Background: involves: C57BL/6J

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

mortality/aging

perinatal lethality, complete penetrance ( J:262458 )

• newborns die within a few hours after birth

integument

impaired skin barrier function ( J:262458 )

• E18.5 mutants show defective skin barrier

abnormal epidermis stratum basale morphology ( J:262458 )

• disorganization of the basal layer

abnormal epidermis stratum corneum morphology ( J:262458 )

• mice exhibit higher density of corneodesmosomes in both the lower and upper layers of the stratum corneum indicating persistence of corneodesmosomes

• incomplete cornification is seen in stratum corneum with cells appearing transitional

• stratum corneum shows defects in lipid accumulation, with a reduction in glucosylceramide/ceramide levels and lamellar bodies with no lamellar cargo

hyperkeratosis ( J:262458 )

• hyperkeratotic epidermis in E18.5 mutants, with the stratum corneum containing twice as many layers as wild-type skin at E18.5

• treatment of grafted mutant skin onto the back of immunocompromised skin with a cream containing recombinant KLK5 and KLK7 enzymes results in the peeling of the top layers and sloughing of the hyperkeratotic stratum corneum

parakeratosis ( J:262458 )

• parakeratosis in the stratum corneum

impaired stratum corneum desquamation ( J:262458 )

• severe desquamatory defects in the epidermis, with retention of corneocytes and desmosomal/corneodesmosomal components

• corneocytes in epidermis are tightly attached to each other even after prolonged attempts to separate them

abnormal epidermal lamellar body morphology ( J:262458 )

• skin shows abnormal lamellar bodies and the absence of lipid lamellae in the epidermis

thick epidermis stratum granulosum ( J:262458 )

• expansion of the granular layer

thin epidermis stratum spinosum ( J:262458 )

• reduction in the size of the spinous layer

dry skin ( J:262458 )

• newborns appear severely dehydrated with dry cracking skin

shiny skin ( J:262458 )

tight skin ( J:262458 )

• by E18.5, mutants develop a taut, thick skin and limb contractures

translucent skin ( J:262458 )

abnormal skin development ( J:262458 )

• E16.5 mutants develop a partial absence of normal skin folds around the trunk and limbs

• marker analysis indicates that terminal differentiation is deregulated in epidermis

• however, hair follicles appear to develop normally

abnormal keratinocyte physiology ( J:262458 )

• reduction of lipid secretion from stratum granulosum keratinocytes

homeostasis/metabolism

dehydration ( J:262458 )

• newborns appear severely dehydrated with dry cracking skin

impaired skin barrier function ( J:262458 )

• E18.5 mutants show defective skin barrier

Mouse Models of Human Disease		DO ID	OMIM ID(s)	Ref(s)
autosomal recessive congenital ichthyosis 4B		DOID:0060713	OMIM:242500	J:262458