Analysis of CYP2D6 Allele Frequencies and Identification of Novel SNPs and Sequence Variations in Sardinians

Table 6

CYP2D6 allele frequencies detected in 250 healthy Sardinian people and previous frequencies found in reference populations. In these results, “Sardinian haplotypes 1” and “2” are considered as part of CYP2D6*41 allele, instead “Sardinian haplotypes 3 and 4” are considered as part of CYP2D6*2 allele.

Variant allele	Sardinian frequencies (%); (𝑛=250)	Sardinian frequencies (%); (𝑛=28) [11]	Sardinian frequencies (%); (𝑛=48) [12]	Mediterranean frequencies (%); (𝑛=247) [12]	German frequencies (%); (𝑛=589) [18]	White subjects frequencies (%); (𝑛=308) [23]	European frequencies (%); (𝑛=672) [24, 25]	Caucasian frequencies (%) [26]	Correlated enzymatic activity [5]
* 1	31.4	28.6	36.5	40.8ª	36.4	36.4	33.4	nd	EM
* 2	20.4	35.7	40.6	37.1ª	32.4	17.5	32.9	nd	EM
* 3	2.2	1.8	3.1	1.5	2.0	nd	1.8	nd	PM
* 4	16.8	21.4	12.5	16.0ª	20.7	nd	18.9	12–21	PM
* 5	1.0	1.8	1.0	nd	2.0	nd	7.3	4–6	PM
* 6	0.2	—	—	0.8	0.9	nd	1.4	nd	PM
* 9	0.2	—	—	0.6	1.8	2.1	2.6	nd	IM
* 10	5.4	5.4	4.2	2.9	1.5	1.8	1.4	1-2	IM
* 15	0.6	nd	nd	nd	0.1	nd	nd	nd	PM
* 20	0.2	nd	nd	nd	nd	nd	nd	nd	PM
* 28	0.8	nd	nd	nd	nd	nd	nd	nd	Not known
* 35	1.0	nd	nd	nd	nd	5.2	nd	nd	EM
* 41	17.8	3.6	nd	nd	nd	8.4	nd	nd	IM
* 1 ×N	0.8	—	—	nd	0.5	—	nd	nd	UM
* 2 ×N	1.2	1.8	2.1	nd	1.3	1.1	nd	1–5	UM

—: allele not found in the study; nd: allele not detected in reference study; ^aincluding duplications/multiduplications of haplotype.