Altered allelic distributions of the serotonin transporter gene in migraine without aura and migraine with aura

Allelic variation of the human serotonin transporter gene (HSERT), a highly plausible candidate gene for susceptibility to migraine, was investigated in 266 individuals with migraine, including 173 having migraine without aura (MO), 94 having migraine with aura (MA), 18 with co-occurrence of MO and MA, plus 133 unaffected controls. The distribution of a polymorphism with different forms of a variable tandem number repeat (VNTR) in intron 2 were compared. The MO group had an over-representation of genotypes with two twelve repeat alleles (STin2.12) and a reduction of genotypes containing one ten repeat (STin2.10) compared to controls. The MA group showed a similar pattern, but also a trend towards an increase in genotypes containing the nine repeat allele of the VNTR (STin2.9). Genotypes containing this allele were found in 6.4% of the MA group compared to 2.3% of controls. The group with co-occurrence of MO and MA had a significantly different pattern of overall allele frequency distribution from controls...