Contribution of serotonin transporter gene polymorphisms to pediatric migraine

Background.-The serotonin transporter gene is a promising candidate locus for the genetic susceptibility of migraine. Objective.-Two functional polymorphisms of the serotonin transporter gene (5-HTTLPR and STin2) were analyzed to assess whether these variants are associated with pediatric migraine. Methods.-Eighty-seven Hungarian pediatric migraine patients and 464 controls were genotyped using polymerase chain reaction. Patients suffering from migraine with (n = 38) or without aura (n = 49) were interviewed regarding the clinical symptoms before or during the attacks. Results.-There was no difference between genotype or allele distribution of 5-HTTLPR and STin2 polymorphisms in the entire group of migraineurs and controls. Analysis of subgroups showed an association between STin2 and migraine with aura, as the 12,12 homozygote genotype was overrepresented in this group of patients. Furthermore, similar allele and genotype patterns were found in cases with severe vomiting and abdominal pain. Conclusions.-These results confirm and extend the association between the STin2 polymorphism of 5-HTT gene and migraine with aura using pediatric probands. Our data also suggest a novel endophenotype for pediatric migraine characterized by excessive vomiting and abdominal pain during the attack.