CYP2C19*37 is assigned no function based on limited evidence. CYP2C19*37 is a partial deletion of the CYP2C19 gene and was identified by interrogation of multiple databases of clinical chromosomal microarray data (31260137). Therefore, because a partial gene deletion is not expected to result in a functional protein, consensus among experts was no function based on limited evidence as it was determined the phenotypes containing this allele would be clinically distinct from phenotypes comprising normal function and decreased function alleles.