Categories: Nervous system phene

Possibly relevant human trait(s) and/or gene(s) (MIM number): 608182 (gene)

Links to MONDO diseases: No links.

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2020

Molecular basis: By whole-genome sequencing two affected Norwegian Buhund sibs, comparing these sequences against 405 whole-genome sequences from other breeds, and then extensively genotyping the most likely variant, Jenkins et al. (2020) identified the most likely causal variant as "a T to C single nucleotide polymorphism (SNP) (NC_006585.3:g.88890674T>C), [that] is predicted to cause a tryptophan to arginine substitution in a highly conserved region of the potassium voltage-gated channel interacting protein KCNIP4. This gene has not been implicated previously in hereditary ataxia in any species. Evaluation of KCNIP4 protein expression through western blot and immunohistochemical analysis using cerebellum tissue of affected and control dogs demonstrated that the mutation causes a dramatic reduction of KCNIP4 protein expression. The expression of alternative KCNIP4 transcripts within the canine cerebellum, and regional differences in KCNIP4 protein expression, were characterised through RT-PCR and immunohistochemistry respectively. The voltage-gated potassium channel protein KCND3 has previously been implicated in spinocerebellar ataxia, and our findings suggest that the Kv4 channel complex KCNIP accessory subunits also have an essential role in voltage-gated potassium channel function in the cerebellum and should be investigated as potential candidate genes for cerebellar ataxia in future studies in other species."

Breed: Norwegian Buhund.

Associated gene: