Wal Mutant Mice Have a Mutation Associated with Autism Spectrum Disorders.

Area of Science:

• Genetics
• Molecular Biology
• Animal Models

Background:

• The waved alopecia (wal) mutation in mice causes a distinctive wavy coat and progressive hair thinning.
• The precise genetic cause of the wal mutation and its location within mouse chromosome 14 were previously undetermined.

Purpose of the Study:

• To identify the molecular basis of the spontaneous waved alopecia (wal) mutation in mice.
• To investigate candidate genes within the mapped wal locus and perform genome-wide sequencing.

Main Methods:

• Sequencing of candidate gene exons within the defined wal locus.
• Genome-wide sequencing to identify causative mutations.
• Analysis of identified mutations for association with the wal phenotype.

Main Results:

• No causative mutations were found within the candidate genes at the wal locus.
• A spontaneous mutation was identified in the Slc9a9 gene, located outside the wal locus.
• This Slc9a9 mutation is unlikely to be associated with the observed waved alopecia phenotype.

Conclusions:

• The genetic defect responsible for the waved alopecia (wal) phenotype remains unidentified.
• A novel spontaneous mutation in the Slc9a9 gene was discovered in mice, unrelated to the wal phenotype.
• This finding represents the first reported spontaneous Slc9a9 mutation in mice, a gene linked to autism spectrum disorders.