The ear askew mutation is homozygous embryonic lethal. Heterozygotes have unilateral or bilateral low-set ears and malformed pinna. There is variable expressivity. Heterozygotes are viable and fertile, but auditory brainstem response assessment shows severe hearing loss at 6 months of age.
The ear askew mutation arose spontaneously in the strain BALB/cByJ-Agtpbppcd-3J/J at The Jackson Laboratory in 2001. This mutant subline has been maintained by sibling intercrossing heterozygotes with wild-type siblings and the -Agtpbppcd-3J mutation was bred out. In 2009 his strain reached generation +F16 and sperm was cryopreserved from heterozygous males.
|Allele Name||ear askew|
|Gene Symbol and Name||Fgfr1, fibroblast growth factor receptor 1|
|Strain of Origin||BALB/cByJ-Agtpbp1pcd-3J/J|
|Molecular Note||This spontaneous point mutation is a C-to-G transversion at position 25,557,813 (GRCm38) that results in an asparagine to lysine substitution at amino acid 147 (p.N147K).|