Mouse Genome Informatics
phenotype observed in females
phenotype observed in males
N normal phenotype
• death by 12 days of age (J:41426)
• homozygotes die between 5 and 12 days of age (J:79976)
• death caused by dehydration a result of increased transepidermal water loss (J:90417)

• mitochondria in epidermis are larger, vesiculated, and contain lamellar-like structures that become dense and homogeneous
• increase in keratinocyte proliferation

endocrine/exocrine glands
• glands are small, infrequent and immature

• 50% loss by day 11

• increase in keratinocyte proliferation
• glands are small, infrequent and immature
• does not develop normal first hair coat
• few hair fibers emerge
• hair fibers have a prominent collar of cornified cells and break off near the surface
• cuticular defects including linear striation, perforations and pealing scales
• root sheaths are hyperplastic and cornified
• thickening from the junction of the infundibula to the junction of the dermis and hypodermal fat layer
• neutrophil and mast cell infiltration between follicles
• mitochondria in epidermis are large, vesiculated, and contain lamellar-like structures that become dense and homogeneous
• hair fiber remnants extend into stratum corneum
• contains an abundance of vacuoles or degenerating organelles
• stratum corneum is thickened
• beginning at 6 days of age homozygotes develop a layer of compact orthokeratotic scales, initially on the dorsal skin
• in interfollicular epidermis and follicular infundibular region
• interfollicular epidermis and stratum corneum are thickened
• thick white (orthokeratotic) scales beginning at 5 days of age
• develops thick white coating by 9 days, primarily dorsal skin
• thick fold on anterior, dorsal, truncal skin
• compared to controls 6-8 day old mice exhibit increased thickness in dermis, malphigian layer and scale
• hypodermal fat layer and follicle length are not significantly thicker

Mouse Models of Human Disease
Ichthyosis, Congenital, Autosomal Recessive 4b; ARCI4B 242500 J:41426 , J:90417