OMIA:000698-9940 : Myotonia in Ovis aries (sheep)

In other species: dog , domestic cat , horse , pig , taurine cattle , goat , water buffalo

Categories: Muscle phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 160800 (trait) , 255700 (trait) , 118425 (gene)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2015

Cross-species summary: Myotonia congenita

Molecular basis: Using a comparative candidate gene approach (based on the same clinical signs being due to mutations in CLCN1 in goats, horse and humans [see related entries at the top of this page]), Monteagudo et al. (2015) sequenced this gene in two affected lambs and three unrelated unaffecteds from Spanish flocks of the Rasa Aragonesa breed. They reported "In the second exon, a g.106140081G>A transversion was found in homozygosity in both affected individuals (GenBank number NC_019461.1 numbering), resulting in a p.Gln93Lys substitution in the amino acid sequence. Both lambs were born from ewes heterozygous for this SNV (GA), verified by DNA sequencing. Five of the 27 rams in service at the farm were also found to be heterozygous GA, while the remainder was homozygous GG. No AA individuals were detected among the adult individuals." 40 unrelated rams from other flocks were homozygous GG. Importantly, "Removing the GA rams in May 2013 and replacing them with GG rams from the same flock allowed us to prevent occurrence of homozygous AA new-born lambs in the flock and to confirm association between the SNV [single nucleotide variant] and the pathology. As of 22 December 2014, no additional affected lambs had been born, further supporting the role of this SNV in the pathology."

Clinical features: As reported by et al. (2015) "The symptoms were visible only after sudden visual and/or auditory stimulation or fast movements during normal flock management. When other individuals in the lot started evasive movements, the affected lambs maintained a rigid position with extended limbs and frequently fell to the ground. After 6–25 s, the lambs were able to stand and move normally."

Breed: Rasa Aragonesa, Spain (Sheep) (VBO_0015863).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
CLCN1 chloride channel, voltage-sensitive 1 Ovis aries 4 NC_056057.1 (107922466..107961042) CLCN1 Homologene, Ensembl , NCBI gene


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.

Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.

OMIA Variant ID Breed(s) Variant Phenotype Gene Allele Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
1664 Myotonia CLCN1 unpublished Entry has been created to generate an OMIAvariantID for a variant that is currently in the process of being published. Information will be updated once manuscript has been published. 2024 Reference not in PubMed; see OMIA 000698-9940 for reference details
245 Rasa Aragonesa, Spain (Sheep) Myotonia CLCN1 missense Naturally occurring variant Oar_rambouillet_v1.0 4 g.115541101G>A c.277G>A p.(E93K) Oar_v3.1 position is g.106140081G>A published as p.Gln93Lys. cDNA and protein position predicted using Variant Effect Predictor ENSOART00020002372.1 rs401726021 2015 25744800 The genomic location on Oar_rambouillet_v1.0 was determined by Katie Eager, EMAI, NSW Department of Primary Industries.

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2015). OMIA:000698-9940: Online Mendelian Inheritance in Animals (OMIA) [dataset].


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.

2024 [No authors listed] :
2023 Xie, S., Isaacs, K., Becker, G., Murdoch, B.M. :
A computational framework for improving genetic variants identification from 5,061 sheep sequencing data. J Anim Sci Biotechnol 14:127, 2023. Pubmed reference: 37779189. DOI: 10.1186/s40104-023-00923-3.
2015 Monteagudo, L.V., Tejedor, M.T., Ramos, J.J., Lacasta, D., Ferrer, L.M. :
Ovine congenital myotonia associated with a mutation in the muscle chloride channel gene. Vet J 204:128-9, 2015. Pubmed reference: 25744800. DOI: 10.1016/j.tvjl.2015.01.014.
1997 Moore, G.A., Dyer, K.R., Dyer, R.M., Sponenberg, D.P. :
Autosomal recessive myotonia congenita in sheep Genetics Selection Evolution 29:291-294, 1997. DOI: 10.1186/1297-9686-29-2-291.

Edit History

  • Created by Frank Nicholas on 06 Sep 2005
  • Changed by Frank Nicholas on 08 Mar 2015