Associations Between Variations in TPH1, TPH2 and SLC6A4 Genes and Postpartum Depression: A Study in the Jordanian Population

In this study, we investigated the association between tryptophan hydroxylase-1 (TPH1) (218A>C), tryptophan hydroxylase-2 (TPH2) (1463G>A) and serotonin carrier family 6, member 4 (SLC6A4) [long (L) vs. short (S)] gene polymorphisms with postpartum depression (PPD) in women from Jordan. A total of 370 postpartum (130 depressed and 240 non depressed) women volunteered for the study. Genotyping was carried out using restriction fragment length polymorphism (RFLP) for TPH1, amplification refractory mutation system (ARMS) for TPH2 and polymerase chain reaction (PCR) for SLC6A4 S and L. The Edinburgh postnatal depression scale was used to screen postpartum women. Both S and L alleles of SLC6A4 are common in Jordanian women (about 51.0 and 49.0%, respectively), while allele TPH1-218C is more common (64.0%) than allele A (37.0%). Regarding TPH2, allele A is absent from the examined women. None of the examined polymorphisms were found to be associated with PPD (p >0.05). However, depression history, pregnancy problems and economic status were found to be significantly associated with PPD (p <0.05). The results suggest that TPH1, TPH2 and SLC6A4 S and L polymorphisms do not seem to be important in Jordan for predisposing to PPD.