CMGS/VKGL suggested classification

The Practice guidelines for the Interpretation and Reporting of Unclassified Variants (UVs) in Clinical Molecular Genetics suggest the following classification system:

• Class 1 – Certainly not pathogenic
• Class 2 – Unlikely to be pathogenic but cannot be formally proven
• Class 3 – Likely to be pathogenic but cannot be formally proven
• Class 4 - Certainly pathogenic

(Note that the guidelines specify that "...it is not considered essential to use a classification system such as this".)

Bell J, Bodmer D, Sistermans E, Ramsden SC: Practice guidelines for the interpretation and reporting of unclassified variants (UVs) in clinical molecular genetics.
Guidelines ratified by the UK CMGS (11th January, 2008) and the VGKL (22nd October, 2007).
http://cmgsweb.shared.hosting.zen.co.uk/BPGs/Best_practice_Guidelines.htm