OMIA 001723-9940 : Ataxia, familial episodic spinocerebellar in Ovis aries

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal Incompletely Dominant

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2017

Inheritance: Based on the results of mating the two unaffected rams (that had previously produced affected offspring) with unrelated ewes, Mayhew et al. (2012) concluded that this disorder is "a dominant trait, with incomplete penetration of observed clinical signs and variable expressivity."

Molecular basis: Dittmer et al. (2017): "Using whole genome sequencing of two half-sib affected lambs, their sire, and their two normal dams, a heterozygous C>T transition at OAR10:77593415 (Oar_v3.1) in exon 1 of the fibroblast growth factor 14 (FGF14) gene (c.46C>T) was identified. The c.46C>T transition resulted in a premature stop codon at position 16 of the 247 amino acid FGF14 protein (p.Q16*). PCR and Sanger sequencing was used to genotype an additional 20 clinically affected animals, demonstrating all lambs carried the c.46C>T variant but 1 clinically more severely affected inbred lamb was homozygous (TT)."

Clinical features: As reported by Mayhew et al. (2012) "Some lambs were noted to be abnormal at birth, both on home properties and in the experimental flock. They tended to adopt a head and neck extended posture and were slow to get to their feet and suckle when they then became more or less normal. When forced to move, they and other more robust lambs elicited an asymmetric gait, base-wide extensor hypertonia (hypometria) of thoracic limbs and flexor hypertonia (hypermetria) of pelvic limbs. In some there was nystagmus. After several metres of asymmetric ataxic gait they would fall to one side, sometimes adopting a sitting position. Recovery usually occurred in one to several minutes. As lambs aged, it became more difficult to elicit the episodes of dysfunction and by 6 months of age they appeared normal".

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
FGF14 fibroblast growth factor 14 Ovis aries 10 NC_040261.1 (88622194..87975960) FGF14 Homologene, Ensembl, NCBI gene

Variants

By default, variants are sorted chronologically by year of publication, to provide a historical perspective. Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column headers.

WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Breed(s) Variant Phenotype Gene Allele Type of Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
Romney Marsh Familial episodic ataxia FGF14 nonsense (stop-gain) Oar_v3.1 10 g.77593415C>T c.46C>T p.Q16* 2017 29253853

References


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.
2017 Dittmer, K.E., Jolly, R.D., Mayhew, I.G., Ridler, A.L., Chernyavtseva, A., Garrick, D.J., Blair, H.T. :
Familial episodic ataxia in lambs is potentially associated with a mutation in the fibroblast growth factor 14 (FGF14) gene. PLoS One 12:e0190030, 2017. Pubmed reference: 29253853. DOI: 10.1371/journal.pone.0190030.
2013 Mayhew, I.G., Jolly, R.D., Burnham, D., Ridler, A.I., Poff, G.J., Blair, H.T. :
Familial episodic ataxia in lambs. N Z Vet J 61:107-10, 2013. Pubmed reference: 22985028. DOI: 10.1080/00480169.2012.717501.

Edit History


  • Created by Frank Nicholas on 17 Oct 2012
  • Changed by Frank Nicholas on 19 Jan 2018