Although in some cases the pathogenicity of a CNV can be inferred from the molecular analysis (e.g., CNVs removing both HBA1 and HBA2 causing α-thalassaemia), the interpretation of CNVs should combine evidence about the disease mechanism, phenotype, and mode of inheritance, as suggested by the ACMG/AMP guidelines. The gene discussed is HBA2; the disease is thalassemia.