Abstract: Presently, clinical genetic testing reports for genetic patients mainly describe the pathogenicity of gene variations and their clinical implications. When writing reports, laboratory staff often focus on the nature of variation itself. However, clinicians have to face the referred cases, so their focus is mainly on the clinical situation of cases. This situation often causes clinicians to misunderstand test reports. The paper proposes a five-tier categorization system of the sequence variation findings based on their clinical significance. That is, the genetic test report should not only classify the pathogenicity of gene variants, but also include the classification of clinical significance. This protocol recommended that the clinical significance of gene mutation be divided into five levels: variants with strong clinical significance, variants with potential clinical significance, variants of unknown clinical significance, unexpected secondary findings and variants with no important clinical significance. This protocol emphasizes the importance of accuracy and comprehensiveness of clinical phenotypes and the importance of laboratory-clinical communication. The standardization of phenotype description is advocated. These recommendations will promote the mutual understanding for the clinicians and laboratory staff, and will be helpful for the interpretation of the testing reports and genetic counseling.

Key words: genetic testing, genetic variation, genetic counseling, pathogenicity classification, clinical significance, result interpretation