Testing for specific variants known to cause disease. Examples include: (1) one or more specific pathogenic variants (e.g., Glu6Val for sickle cell anemia, a panel of pathogenic variants for cystic fibrosis); (2) a nucleotide repeat expansion (e.g., the trinucleotide repeat expansion associated with Huntington disease); and (3) common deletions (e.g., population-specific alpha globin gene deletions).