C679X

C679X is a designation that can refer to more than one concept depending on the context, but it is most commonly encountered as a protein-level mutation notation in genetics. In this usage, C679X denotes a nonsense mutation at position 679 where the cysteine (C) is replaced by a stop codon (X). This results in premature termination of the protein, potentially producing a truncated polypeptide with loss of downstream regions and altered or abolished function. The biological impact depends on the gene, the protein’s length, and the importance of the affected domains. Such variants are described in genetic databases and literature with the associated gene symbol, organism, and transcript or protein accession to specify the exact context.

Outside of genetics, C679X can appear as a model number, product code, or internal designation in various industries. In those cases, the meaning is not standardized and requires additional context to identify what entity the label refers to.

When used in a clinical or research setting, identifying a C679X variant typically involves sequencing or targeted genotyping to confirm the cysteine-to-stop change, followed by analyses to assess potential phenotypic consequences. Documentation usually includes the specific gene, isoform, and methodological details to enable reproducibility.

In summary, C679X most often denotes a stop-gain mutation at residue 679 in protein-coding genes, but its exact meaning depends on the surrounding context and should be clarified with accompanying gene and species information.