Homozygotes can be identified as early as 7 to 8 days of age when the first coat comes in. The hair growth is sparse and grows in stripes with bald areas between. The areas around the eyes often develop a mild, crusty growth and rash. All four hair types are present. Of two homozygotes tested both display a low cone response by electroretinograph.
The atypical hair loss (aphl) mutation arose spontaneously at The Jackson Laboratory on the MRL/MpJ-Faslpr/J background in 2006 and was backcrossed to MRL/MpJ to via backcross-intercross breeding to remove the Faslpr mutation. When this strain reached N6 in 2010 and the Faslpr mutation was shown to be removed from the line the breeding scheme changed to sibling mating heterozygotes and homozygotes.
|Allele Name||atypical hair loss|
|Gene Symbol and Name||aphl, atypical hair loss|
|Strain of Origin||MRL/MpJ-Faslpr/J|
|Molecular Note||Whole exome sequencing identified candidate mutations in the UTRs of 3 genes, Eif2ak3, Mrpl35, and Usp39, but none has yet been proven causative.|