Citrullinaemia
- Phene ID
- 32
- Name
- Citrullinaemia
- Phene Name
- N/A
- OMIA ID
- 194
- Species ID
- 9913
- Characterised
- Yes
- Characterised Year
- 1989
| Symbol | Gene ID | Chromosome | Description |
|---|---|---|---|
| ASS1 | 280726 | 11 | argininosuccinate synthase 1 |
| Variant ID | Phenotype | Gene ID | Deleterious | Chromosome | Genomic | Transcript | Protein |
|---|---|---|---|---|---|---|---|
| 289 | Citrullinaemia | 280726 | 1 | 11 | NC_037338.1:g.100781668C>T | NM_173892.4:c.256C>T | NP_776317.1:p.(R86*) |
| Breed | Breed ID | Species ID | VBO Term |
|---|---|---|---|
| Blanco Orejinegro, Colombia (Cattle) | 1340 | 9913 | http://purl.obolibrary.org/obo/VBO_0004602 |
| Brown Swiss (Cattle) | 59 | 9913 | http://purl.obolibrary.org/obo/VBO_0000166 |
| Holstein Friesian (Cattle) | 73 | 9913 | http://purl.obolibrary.org/obo/VBO_0000239 |
To date, all cases of this lethal disorder in cattle appear to be due to the same mutation, namely a nonsense mutation in the 5th of 9 exons of the ASS gene. Normal bovine ASS is a peptide containing 412 amino acids; the mutation occurs in the 86th codon.
By cloning and sequencing a very likely comparative candidate gene (based on the homologous human disorder), Dennis et al. (1989) reported the causative mutation as a C>T transition, altering arginine-86 (CGA) to a nonsense codon (TGA) (Mohammad Shariflou 10/11/2006; FN 19 Sept 2012).
The .0001 mutation destroys a recognition sequence for the restriction enzyme AvaI, thereby generating an RFLP. Dennis et al. (1989) developed a PCR genotyping test based on this RFLP, with primers 100 bp on either side of the mutation site. After AvaI digestion of the PCR product, homozygous normals show a single 100-bp band (containing the fragments on either side of the mutation site), heterozygotes show a 100-bp band and a 200-bp band, and affected calves show a 200-bp band only. This test is now regularly performed on hair follicles, which are far easier to collect from the field than blood (Healy, pers. comm.).