Table 3 Major allele frequencies (%) in the control groups of different studies examining the role of PDE4D in stroke.

SNP	Allele	Münster	Iceland	Munich	Sweden
SNP 45 (rs12188950)	G	85.5	78.0	86.3	88.0
SNP 56 (rs702553)	T	68.7	65.5	NR	NR
SNP 83 (rs966221)	C	61.0	52.0	NR	NR
SNP 87 (rs2910829)	T	53.1	48.4	NR	NR
SNP 89 (rs1396476)	A	83.7	81.8	NR	NR

Major allele frequencies are derived from our own study (Münster) and the studies by Gretarsdottir et al (Iceland),⁵ Lohmussaar et al (Munich),¹⁰ and Nilsson‐Ardnor et al (Sweden).¹¹ Bevan et al¹² did not report allele frequencies of the SNPs. SNP41 is not reported because it received the wrong designation in the original paper by Gretarsdottir et al (rs152312) which was subsequently corrected to rs121537989. As only the study by Nilsson‐Ardnor typed SNP rs121537989 but the other studies typed SNP rs152312 we have not shown the allele frequencies of this SNP.

Allele: A, adenine; C, cytosine; G, guanine; T, thymidine.

NR, not reported; SNP, single nucleotide polymorphism designation.