[A consensus recommendation for the interpretation and reporting of copy number variation and regions of homozygosity in prenatal genetic diagnosis].

Chromosomal microdeletions and microduplications have been proven to be a significant proportion of genetic factors underlying birth defects. Chromosomal microarray analysis (CMA) and next generation sequencing-based copy number variation (CNV-seq) assay have been recommended as first-tier tests for prenatal evaluation of disease-causing CNV across the genome. With the broad application of such technologies in prenatal genetic diagnosis, there is a needed to enhance the consistency in interpretation and reporting of CNV results in clinical laboratories across China. In addition, a standard guideline for prenatal analysis and reporting of regions of homozygosity (ROH) is also required. To assist the classification, interpretation and reporting of CNV/ROH, the following recommendations have been developed, which may enhance a standard application of CMA/CNV-seq techniques in prenatal genetic diagnosis.