multiple COSMIC id for the same mutation I would like to know why there are different entries for the same mutation in COSMIC, for example COSM6954941 and COSM12833 both refer to ERBB4 c.908C>A.

In this specific case the field Gene name in the two entries is different, COSM6954941 report ERBB4_ENST00000402597 while COSM12833 report ERBB4, but there are many cases in which the Gene name is the same, for example COSM1361 and COSM1219.
Harry Boutselakis addressed the question via the customer support of the COSMIC web site.




  Dear Ivan, Thank you for using COSMIC.
  
  
    I would like to know why there are different entries for the same mutation   in COSMIC, for example COSM6954941 and COSM12833 both refer
    to ERBB4   c.908C>A.
    
    In this specific case the field Gene name in the two entries is different,   COSM6954941 report ERBB4_ENST00000402597 while COSM12833
    report ERBB4,
  
  
  The mutations are annotated onto two different isoforms of ERBB4. So
  this annotation refers to two different transcripts. In these cases
  the consequence of the mutation on the mRNA and polypeptide is the
  same reflected by the syntax.
  
  
    but there are many cases in which the Gene name is the same, for example   COSM1361 and COSM1219.
  
  
  This case the consequence one mutation on the mRNA is unknown , but
  the amino acid change is the same on both cases.
  
  The information stored in COSMIC is curated from experimental data,
  depending on the evidence and experimental methodology used, the
  mutations are differentiated accordingly. I hope this answers your
  question.
  
  Kind regards,
  
  Harry