Phenotypes Associated with This Genotype

Genotype
MGI:3807775

• Allelic Composition: Fscn2^ahl8/Fscn2^ahl8
• Genetic Background: DBA/2J

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

hearing/vestibular/ear

decreased inner hair cell stereocilia number ( J:162868 )

• hair bundles appear normal at 2 weeks of age but are progressively lost between 1 and 6 months of age

decreased outer hair cell stereocilia number ( J:162868 )

• degeneration occurs earliest here

abnormal auditory brainstem response ( J:139223 )

• although DBA/2J is homozygous for both Cdh23 and ahl8, through linkage analysis with CAST/Ei, which is wild-type at Cdh23, ahl8 is shown to contribute up to 37% of the 16 kHz ABR threshold variation in 13 week old homozygotes

increased or absent threshold for auditory brainstem response ( J:162868 )

• increased ABR threshold

increased susceptibility to age-related hearing loss ( J:139223 , J:162868 )

• hearing loss is progressive and shows a much earlier onset than in C57BL/6J, with average 16 kHz ABR thresholds approximately 50 dB higher at 10 weeks of age than in 30 week old C57BL/6J (J:139223)

• hearing appears normal at 2 weeks of age but is progressively lost, based upon measurement of auditory brainstem response between 1 and 6 months of age (J:162868)

nervous system

decreased inner hair cell stereocilia number ( J:162868 )

• hair bundles appear normal at 2 weeks of age but are progressively lost between 1 and 6 months of age

decreased outer hair cell stereocilia number ( J:162868 )

• degeneration occurs earliest here