Table 4.

Copy Number Detection for Selected Hybrid Alleles Composed of Portions of CYP2D6 and CYP2D7

Allele	Allele functional status†	Reference material available	Multiethnic allele frequency	Hybrid type	5′ UTR‡	Exon 1‡	Intron 2‡	Intron 5‡	Intron 6‡	Exon 9‡
∗4.013 (∗4N)	No function			2D6-2D7	Yes	Yes	Yes	Yes	Yes	No
∗13	No function	Yes	0%–0.4%	2D7-2D6	No	No	Yes/no	Yes/no	Yes/no	Yes§
∗36	No function	Yes	0%–1.2%	2D6-2D7	Yes	Yes	Yes	Yes	Yes	No
∗68	No function	Yes	Not available	2D6-2D7	Yes	Yes	No¶	No¶	No¶	No
∗83	Uncertain function	Yes	Not available	2D6-2D7	Yes	Yes	Yes	Yes	Yes	No

CPIC, Clinical Pharmacogenetics Implementation Consortium; HGVS, Human Genome Variation Society.

^†Allele functional status corresponds to CPIC clinical allele function assignments as listed in the CYP2D6 Allele Functionality Table available through PharmGKB (https://www.pharmgkb.org/page/cyp2d6refmaterials, last accessed June 2, 2021); these function assignments are also displayed by the Pharmacogene Variation Consortium.

^‡Signal present on copy number analysis for this allele.

^§A hybrid with a switch to CYP2D6 past exon 9 has been described in tandem arrangements; these are technically also CYP2D7-2D6 hybrids and produce no signal across any of the listed regions.

^¶It cannot be ruled out that rare/undefined hybrids switch in different regions affecting the copy number call in that region.