Abstract: Genomic microarrays used to assess DNA copy number are now recommended as first-tier tests for the postnatal evaluation of individuals with intellectual disability，autism spectrum disorders，and/or multiple congenital anomalies. Application of this technology has resulted in the discovery of widespread copy number variation in the human genome，both polymorphic variation in healthy individuals and novel pathogenic copy number imbalances. To assist clinical laboratories in the evaluation of copy number variants and to promote consistency in interpretation and reporting of genomic microarray results，the American College of Medical Genetics has developed the following professional guidelines for the interpretation and reporting of copy number variation. These guidelines apply primarily to evaluation of constitutional copy number variants detected in the postnatal setting.

Key words: CNV, Copy number variant, Microarray, aCGH, CMA